CA2503042C - Method and apparatus for adapting antenna array using received predetermined signal - Google Patents
Method and apparatus for adapting antenna array using received predetermined signal Download PDFInfo
- Publication number
- CA2503042C CA2503042C CA002503042A CA2503042A CA2503042C CA 2503042 C CA2503042 C CA 2503042C CA 002503042 A CA002503042 A CA 002503042A CA 2503042 A CA2503042 A CA 2503042A CA 2503042 C CA2503042 C CA 2503042C
- Authority
- CA
- Canada
- Prior art keywords
- weight control
- signal
- quality metric
- antenna
- signal quality
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/12—Supports; Mounting means
- H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
- H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
- H01Q1/241—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM
- H01Q1/246—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for base stations
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
- H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
- H01Q3/2605—Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
- H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
- H01Q3/28—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the amplitude
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
- H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
- H01Q3/30—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array
- H01Q3/34—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array by electrical means
- H01Q3/36—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array by electrical means with variable phase-shifters
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
- H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
- H04B7/0617—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal for beam forming
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
- H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining
- H04B7/0842—Weighted combining
- H04B7/086—Weighted combining using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
Abstract
An antenna apparatus that can increase capacity in a wireless communication system is disclosed. The antenna operates in conjunction with a station and comprises a plurality of antenna elements (101-n), each coupled to a respective weight control component (111-n) to provide a weight to the signal transmitted from (or received by) each element. The weight for each antenna element is adjusted to achieve optimum reception during, for example, an idle mode when a pilot signal is received. The antenna array creates a beam former for signals to be transmitted from the mobile station, and a directional receiving array to more optimally detect and receive signals transmitted from the base station. By directionally receiving and transmitting signals, multipath fading and intercell interference are greatly reduced. The weights are adjusted in a coarse and a fine mode. In the coarse mode all the weight control components are jointly adjusted or changed so that the antenna beam scans through a predetermined sector of a circle until a signal quality metric of the received signal is optimized. The coarse adjustment mode is followed by a fine adjustment mode during which the weights of are independently adjusted to further optimize the signal quality metric.
Description
METHOD AND APPARATUS FOR ADAPTING
ANTENNA ARRAY USING RECEIVED PREDETERMINED SIGNAL
BACKGROUND OF THE INVENTION
This invention relates to mobile (or portable) cellular communication systems, and more particularly to an antenna apparatus for use by mobile stations to provide beam forming transmission and reception capabilities.
Widely deployed conununication systems, such as cellular mobile telephone systems, provide wireless communications between a base station and one or more mobile stations. The base station is typically a computer controlled set of transceivers that are intercoimected to a land-based public switched telephone network (PSTN). The base station includes an antenna apparatus for sending forward link radio frequency signals to the mobile stations. The base station antenna also receives reverse link radio frequency signals transmitted from each mobile unit. Each mobile station also contains an antenna apparatus for the reception of the forward linlc signals and for transmission of the reverse links signals. A typical mobile station is a digital cellular telephone handset or a personal computer coupled to a cellular modem. In certain cellular systems, multiple mobile stations may transmit and receive signals on the same frequency, but in different time slots or with different modulation codes, to distinguish signals sent to or received from individual stations.
Another increasingly popular type of wireless data communication system is the Wireless Local Area Network (WLAN) such as specified by tlie Institute for Electrical and Electronic Engineers (IEEE) standard 802.11 a and its variants 802.1 lb and 802.11g. Such WLANs are similar to cellular systems in that a coverage area is divided into cells (called Basic Service Sets or BSS in the WLAN
nomenclature) that are controlled by a control base station, known as an Access Point. The remote mobile stations, as in a cellular system, then use the base station to access a communication networlc. WLANs are another type of wireless communication system in which radio frequency channels are shared.
The most coinnlon type of antenna for transmitting and receiving signals at a mobile station is a monopole or oinnidirectional antenna. This type of antenna consists of a single wire or antenna element that is coupled to a transceiver within the station. The transceiver receives reverse linlc signals to be transmitted from circuitry within the station and modulates the signals onto a carrier signal at a specific frequency assigned to that station. The modulated carrier signal is transmitted by the antemia element. Forward link signals received by the antemia elenlent at a specific frequency are demodulated by the transceiver and supplied to processing circuitry within the mobile station.
The signal transmitted from a monopole anteinia is omnidirectional in nature. That is, the signal is sent with the same signal strength in all directions in a generally horizontal plane. Reception of a signal with a monopole antenna element is likewise omnidirectional. A monopole antenna does not differentiate in its ability to detect a signal in one direction versus detection of the same or a different signal conling from another direction. Generally, a monopole antenna does not produce significant radiation in the aziinuth direction. The antenna pattern is commonly referred to as a donut shape with the antenna element located at the center of the donut hole.
A secozid type of antenna that has been used by mobile stations is described in U.S. Pat. No. 5,617,102. The system described therein provides a directional antenna comprising two antenna elements mounted on the outer case of a laptop computer, for example. The systeni includes a phase shifter attached to each element. The phase shifter may be switched on or off to effect the phase of signals transmitted or received during coinmunications to and from the computer.
By switching the phase shifters on and regulating the amount of phase shift imparted to the signals input thereto, the antenna pattern (which applies to both the receive and transmit modes) may be inodified to provide a concentrated signal or beam in the selected direction. This is referred to as an increase in antenna gain or directionality. The dual element antenn.a of the cited patent thereby directs the transinitted signal into predetermined quadrants or directions to allow for changes in orientation of the station relative to the base station, while minimizing sigiial loss due to the orientation change. In accordance with the antenna reciprocity tlieorem, the antenna receive characteristics are similarly effected by the use of the phase shifters.
Wireless systems in which the mobile stations inust share access to radio channels are recognized as being interference limited systems. That is, as more mobile stations become active in a cell and in adjacent cells, frequency interference becomes greater and thus error rates increase. As error rates increase, to maintain signal and system integrity, the operator must decrease the maximum data rates allowable. Tlius, another method by which data rate can be increased is to decrease the number of active mobile stations, thus clearing the airwaves of potential interference. However, this is rarely an effective mechanism to increase data rates due to the lack of priority assignments to the system users.
SUMMARY OF THE INVENTION
Problems of the prior art Various problems are inherent in prior art antemzas used on mobile stations in wireless communications systems. One such problem is called multipatli fading.
In multipath fading, a radio frequency signal transmitted from a sender (either a base station or mobile station) may encounter interference on route to the intended receiver. The signal may, for example, be reflected from objects, such as buildings that are not in the direct path of transmission, but that redirect a reflected version of the original signal to the receiver. In such instances, the receiver receives two versions of the same radio signal; the original version and a reflected version.
Each received signal is at the sanle frequency, but the reflected signal may be out of phase with the original due to the reflection and consequent longer transmission path. As a result, the original and reflected signals may partially cancel each other out (destructive interference), resulting in fading or dropouts in the received signal, hence the terin multipath fading.
Single eleinent antemias are highly susceptible to multipatli fading. A
single element antenna has no way of determining the direction from which a transmitted signal is sent and cannot be tuned or attenuated to more accurately detect and receive a signal in any particular direction. Its directional pattern is fixed by the physical structure of the antenna components.
The dual element anteima described in the aforementioned reference is also susceptible to multipatll fading, due to the syinmetrical and opposing nature of the hemispherical lobes formed by the antenna pattern when the phase shifter is activated. Since the lobes created in the antenna pattern are more or less syinmetrical and opposite from one another, a signal reflected in a reverse direction from its origin can be received with as much power as the original signal that is received directly. That is, if the original signal reflects from an object beyond or bel-iind the intended receiver (with respect to the sender) and reflects back at the intended receiver from the opposite direction as the directly received signal, a phase difference in the two signals can create destructive interference due to multipath fading.
Another problem present is inter-cell interference. Most systems have a base station located at the center of a cell (or the center of a BSS, in the case of a WLAN). The distance from the edge of a cell to its base station is typically driven by the maximum amount of power that is to be required to transmit an acceptable signal from a mobile station located near the edge of the cell to that cell's base station (i.e., the power required to transmit an acceptable signal a distance equal to the radius of one cell).
Intercell interference occurs when a mobile station near the edge of one cell transmits a signal that crosses over the edge into a neighboring cell and interferes with cominunications taking place within the neighboring cell.
ANTENNA ARRAY USING RECEIVED PREDETERMINED SIGNAL
BACKGROUND OF THE INVENTION
This invention relates to mobile (or portable) cellular communication systems, and more particularly to an antenna apparatus for use by mobile stations to provide beam forming transmission and reception capabilities.
Widely deployed conununication systems, such as cellular mobile telephone systems, provide wireless communications between a base station and one or more mobile stations. The base station is typically a computer controlled set of transceivers that are intercoimected to a land-based public switched telephone network (PSTN). The base station includes an antenna apparatus for sending forward link radio frequency signals to the mobile stations. The base station antenna also receives reverse link radio frequency signals transmitted from each mobile unit. Each mobile station also contains an antenna apparatus for the reception of the forward linlc signals and for transmission of the reverse links signals. A typical mobile station is a digital cellular telephone handset or a personal computer coupled to a cellular modem. In certain cellular systems, multiple mobile stations may transmit and receive signals on the same frequency, but in different time slots or with different modulation codes, to distinguish signals sent to or received from individual stations.
Another increasingly popular type of wireless data communication system is the Wireless Local Area Network (WLAN) such as specified by tlie Institute for Electrical and Electronic Engineers (IEEE) standard 802.11 a and its variants 802.1 lb and 802.11g. Such WLANs are similar to cellular systems in that a coverage area is divided into cells (called Basic Service Sets or BSS in the WLAN
nomenclature) that are controlled by a control base station, known as an Access Point. The remote mobile stations, as in a cellular system, then use the base station to access a communication networlc. WLANs are another type of wireless communication system in which radio frequency channels are shared.
The most coinnlon type of antenna for transmitting and receiving signals at a mobile station is a monopole or oinnidirectional antenna. This type of antenna consists of a single wire or antenna element that is coupled to a transceiver within the station. The transceiver receives reverse linlc signals to be transmitted from circuitry within the station and modulates the signals onto a carrier signal at a specific frequency assigned to that station. The modulated carrier signal is transmitted by the antemia element. Forward link signals received by the antemia elenlent at a specific frequency are demodulated by the transceiver and supplied to processing circuitry within the mobile station.
The signal transmitted from a monopole anteinia is omnidirectional in nature. That is, the signal is sent with the same signal strength in all directions in a generally horizontal plane. Reception of a signal with a monopole antenna element is likewise omnidirectional. A monopole antenna does not differentiate in its ability to detect a signal in one direction versus detection of the same or a different signal conling from another direction. Generally, a monopole antenna does not produce significant radiation in the aziinuth direction. The antenna pattern is commonly referred to as a donut shape with the antenna element located at the center of the donut hole.
A secozid type of antenna that has been used by mobile stations is described in U.S. Pat. No. 5,617,102. The system described therein provides a directional antenna comprising two antenna elements mounted on the outer case of a laptop computer, for example. The systeni includes a phase shifter attached to each element. The phase shifter may be switched on or off to effect the phase of signals transmitted or received during coinmunications to and from the computer.
By switching the phase shifters on and regulating the amount of phase shift imparted to the signals input thereto, the antenna pattern (which applies to both the receive and transmit modes) may be inodified to provide a concentrated signal or beam in the selected direction. This is referred to as an increase in antenna gain or directionality. The dual element antenn.a of the cited patent thereby directs the transinitted signal into predetermined quadrants or directions to allow for changes in orientation of the station relative to the base station, while minimizing sigiial loss due to the orientation change. In accordance with the antenna reciprocity tlieorem, the antenna receive characteristics are similarly effected by the use of the phase shifters.
Wireless systems in which the mobile stations inust share access to radio channels are recognized as being interference limited systems. That is, as more mobile stations become active in a cell and in adjacent cells, frequency interference becomes greater and thus error rates increase. As error rates increase, to maintain signal and system integrity, the operator must decrease the maximum data rates allowable. Tlius, another method by which data rate can be increased is to decrease the number of active mobile stations, thus clearing the airwaves of potential interference. However, this is rarely an effective mechanism to increase data rates due to the lack of priority assignments to the system users.
SUMMARY OF THE INVENTION
Problems of the prior art Various problems are inherent in prior art antemzas used on mobile stations in wireless communications systems. One such problem is called multipatli fading.
In multipath fading, a radio frequency signal transmitted from a sender (either a base station or mobile station) may encounter interference on route to the intended receiver. The signal may, for example, be reflected from objects, such as buildings that are not in the direct path of transmission, but that redirect a reflected version of the original signal to the receiver. In such instances, the receiver receives two versions of the same radio signal; the original version and a reflected version.
Each received signal is at the sanle frequency, but the reflected signal may be out of phase with the original due to the reflection and consequent longer transmission path. As a result, the original and reflected signals may partially cancel each other out (destructive interference), resulting in fading or dropouts in the received signal, hence the terin multipath fading.
Single eleinent antemias are highly susceptible to multipatli fading. A
single element antenna has no way of determining the direction from which a transmitted signal is sent and cannot be tuned or attenuated to more accurately detect and receive a signal in any particular direction. Its directional pattern is fixed by the physical structure of the antenna components.
The dual element anteima described in the aforementioned reference is also susceptible to multipatll fading, due to the syinmetrical and opposing nature of the hemispherical lobes formed by the antenna pattern when the phase shifter is activated. Since the lobes created in the antenna pattern are more or less syinmetrical and opposite from one another, a signal reflected in a reverse direction from its origin can be received with as much power as the original signal that is received directly. That is, if the original signal reflects from an object beyond or bel-iind the intended receiver (with respect to the sender) and reflects back at the intended receiver from the opposite direction as the directly received signal, a phase difference in the two signals can create destructive interference due to multipath fading.
Another problem present is inter-cell interference. Most systems have a base station located at the center of a cell (or the center of a BSS, in the case of a WLAN). The distance from the edge of a cell to its base station is typically driven by the maximum amount of power that is to be required to transmit an acceptable signal from a mobile station located near the edge of the cell to that cell's base station (i.e., the power required to transmit an acceptable signal a distance equal to the radius of one cell).
Intercell interference occurs when a mobile station near the edge of one cell transmits a signal that crosses over the edge into a neighboring cell and interferes with cominunications taking place within the neighboring cell.
Typically, intercell interference occurs when similar frequencies are used for communications in neighboring cells. The problem of intercell interference is coinpounded by the fact that stations near the edges of a cell typically use higher transmit powers so that the signals they transmit can be effectively received by the intended base station located at the cell center. Consider that the signal from another mobile station located beyond or behind the intended receiver may be arrive at the base station at the same power level, representing additional interference.
The intercell interference problem is exacerbated in Code Division Multiple Access (CDMA), since the stations in adjacent cells may typically be transmitting on the same frequency at the same time. For example, generally, two stations in adjacent cells operating at the same carrier frequency but transmitting to different base stations will interfere with each other if both signals are received at one of the base stations. One signal appears as noise relative to the other. The degree of interference and the receiver's ability to detect and demodulate the intended signal is also influenced by the power level at which the stations are operating. If one of the stations is situated at the edge of a cell, it transmits at a higher power level, relative to other units witliin its cell and the adjacent cell, to reach the intended base station. But, its signal is also received by the unintended base station, i.e., the base station in the adjacent cell. Depending on the relative power level of two sanie-carrier frequency signals received at the unintended base station, it may not be able to properly identify a sigrial transmitted from within its cell from the signal transmitted from the adjacent cell. What is needed is a way to reduce the station anteiuia's apparent field of view, which can have a marked effect on the operation of the forward link (base to the mobile station) by reducing the apparent nuinber of interfering transmissions received at a base station.
A
similar iinprovement is needed for the reverse link, so that the transmitted signal power needed to achieve a particular receive signal quality can be reduced.
The intercell interference problem is exacerbated in Code Division Multiple Access (CDMA), since the stations in adjacent cells may typically be transmitting on the same frequency at the same time. For example, generally, two stations in adjacent cells operating at the same carrier frequency but transmitting to different base stations will interfere with each other if both signals are received at one of the base stations. One signal appears as noise relative to the other. The degree of interference and the receiver's ability to detect and demodulate the intended signal is also influenced by the power level at which the stations are operating. If one of the stations is situated at the edge of a cell, it transmits at a higher power level, relative to other units witliin its cell and the adjacent cell, to reach the intended base station. But, its signal is also received by the unintended base station, i.e., the base station in the adjacent cell. Depending on the relative power level of two sanie-carrier frequency signals received at the unintended base station, it may not be able to properly identify a sigrial transmitted from within its cell from the signal transmitted from the adjacent cell. What is needed is a way to reduce the station anteiuia's apparent field of view, which can have a marked effect on the operation of the forward link (base to the mobile station) by reducing the apparent nuinber of interfering transmissions received at a base station.
A
similar iinprovement is needed for the reverse link, so that the transmitted signal power needed to achieve a particular receive signal quality can be reduced.
Brief description of the present invention The present invention provides an inexpensive antenna apparatus for use with a mobile or portable station in a wireless same-frequency communications system, such as a CDMA cellular coinmunications system or WLAN system.
The invention provides a mechanism and method for efficiently configuring the antemia apparatus to maximize the effective radiated and/or received energy. The antenna apparatus includes multiple antenna elements and a lilce number of adjustable weight control colnponents. As is well known in the art, the weight control coinponents are controllable to adjust the phase, amplitude and/or delay of the signal coupled to each of the antenna elements. The weight control components (e.g., phase shifter, delay line, amplifier with variable gain) are jointly and independently operable to affect the direction of reverse link signals transmitted from the station on each of the antenna elements and the direction of forward link signals transinitted from the station.
The antenna controller provides a coarse and a fine adjustinent for the weiglit control components. First, the controller jointly controls each of the weight control components to effect the phase of the signal input to each of the antenna elements so that the antenna is pointed generally in a given direction. The controller then shifts to an independent mode where each of the weight control components is independently adjusted to fine tune the antenna pointing direction.
The proper adjustinent of the weight control components in the independent mode can, for exainple, be detennined by monitoring an optimum response to a predetennined signal transmitted from the base station and received by the mobile station.
The exact nature of the predetennined signal depends upon the type of wireless communication system in which the invention is deployed. For a cellular system, the predetenllined signal would typically be a pilot channel signal or access channel signal. In a WLAN system, the predetermined signal can be a beacon frame, Barker sequence, preamble sequence, or other predetermined bit pattern. In general, training sequences, preambles, and similar apriori known signals can also be used for predetermined signal.
The antenna apparatus thus acts as a beam former for transmission of signals from the mobile station and acts as a directional antenna for signals received by the mobile station.
Through the use of an array of antenna elements, each having a programmable weight control component for forming the antenna beam as desired, the antenna apparatus increases the effective transmit power per bit transmitted. Thus, the number of active mobile stations in a cell may remain the same while the antenna apparatus of this invention increases data rates for each station beyond those achievable by prior art antennas.
Alternatively, if data rates are maintained at a given rate, more mobile stations may become simultaneously active in a single cell using the antenna apparatus described herein. In either case, the capacity of a cell is increased, as measured by the sum total of data being communicated at any given time.
Forward link communications capacity can be increased as well, due to the directional reception capabilities of the antenna apparatus. Since the antenna apparatus is less susceptible to interference from adjacent cells, the forward link system capacity can be increased by adding more users or by increasing cell radius size.
According to one embodiment of the present invention there is provided a method for setting optimal weight control component arrangements for a plurality of antenna elements of a transceiver operating in a wireless local area network (WLAN). The method comprises the steps of: (a) receiving a beacon frame from each of the plurality of antenna elements; (b) combining the received beacon frame detected from each of the plurality of antenna elements to produce a combined received beacon frame; and (c) determining a signal quality metric for the combined received beacon frame. The method includes step (d) jointly adjusting the weight control components associated with at least two of the plurality of antenna elements in response to the signal quality metric of the received beacon frame; and (e) repeating the step (d) until an optimum signal quality metric is achieved.
The method further includes step (f) independently adjusting the weight control components in response to the signal quality metric of the received beacon frame; and (g) repeating the step (e) until the determined signal quality metric of the combined received beacon frame reaches an optimum value.
According to another embodiment of the present invention there is provided a mobile station operating within a wireless local area network (WLAN). The mobile station comprises: a plurality of antenna elements; a plurality of weight control components coupled to the plurality of antenna elements; a combiner coupled to the plurality of antenna elements;
and at least one transceiver coupled to the combiner. The mobile station includes a controller coupled to the at least one transceiver and to the plurality of weight control components for setting the plurality of weight control components. The setting of the plurality of weight control components comprises: (a) receiving a beacon frame from each of the plurality of antenna elements; (b) combining the received beacon frame detected from each of the plurality of antenna elements to produce a combined received beacon frame; and (c) determining a signal quality metric for the combined received beacon frame.
The setting further comprises step (d) jointly adjusting the weight control components associated with at least two of the plurality of antenna elements in response to the signal quality metric of the received beacon frame; (e) repeating the step (d) until an optimum signal quality metric is achieved; (f) independently adjusting the weight control components in response to the signal quality metric of the received beacon frame; and (g) repeating the step (e) until the determined signal quality metric of the combined received beacon frame reaches an optimum value.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
The invention provides a mechanism and method for efficiently configuring the antemia apparatus to maximize the effective radiated and/or received energy. The antenna apparatus includes multiple antenna elements and a lilce number of adjustable weight control colnponents. As is well known in the art, the weight control coinponents are controllable to adjust the phase, amplitude and/or delay of the signal coupled to each of the antenna elements. The weight control components (e.g., phase shifter, delay line, amplifier with variable gain) are jointly and independently operable to affect the direction of reverse link signals transmitted from the station on each of the antenna elements and the direction of forward link signals transinitted from the station.
The antenna controller provides a coarse and a fine adjustinent for the weiglit control components. First, the controller jointly controls each of the weight control components to effect the phase of the signal input to each of the antenna elements so that the antenna is pointed generally in a given direction. The controller then shifts to an independent mode where each of the weight control components is independently adjusted to fine tune the antenna pointing direction.
The proper adjustinent of the weight control components in the independent mode can, for exainple, be detennined by monitoring an optimum response to a predetennined signal transmitted from the base station and received by the mobile station.
The exact nature of the predetennined signal depends upon the type of wireless communication system in which the invention is deployed. For a cellular system, the predetenllined signal would typically be a pilot channel signal or access channel signal. In a WLAN system, the predetermined signal can be a beacon frame, Barker sequence, preamble sequence, or other predetermined bit pattern. In general, training sequences, preambles, and similar apriori known signals can also be used for predetermined signal.
The antenna apparatus thus acts as a beam former for transmission of signals from the mobile station and acts as a directional antenna for signals received by the mobile station.
Through the use of an array of antenna elements, each having a programmable weight control component for forming the antenna beam as desired, the antenna apparatus increases the effective transmit power per bit transmitted. Thus, the number of active mobile stations in a cell may remain the same while the antenna apparatus of this invention increases data rates for each station beyond those achievable by prior art antennas.
Alternatively, if data rates are maintained at a given rate, more mobile stations may become simultaneously active in a single cell using the antenna apparatus described herein. In either case, the capacity of a cell is increased, as measured by the sum total of data being communicated at any given time.
Forward link communications capacity can be increased as well, due to the directional reception capabilities of the antenna apparatus. Since the antenna apparatus is less susceptible to interference from adjacent cells, the forward link system capacity can be increased by adding more users or by increasing cell radius size.
According to one embodiment of the present invention there is provided a method for setting optimal weight control component arrangements for a plurality of antenna elements of a transceiver operating in a wireless local area network (WLAN). The method comprises the steps of: (a) receiving a beacon frame from each of the plurality of antenna elements; (b) combining the received beacon frame detected from each of the plurality of antenna elements to produce a combined received beacon frame; and (c) determining a signal quality metric for the combined received beacon frame. The method includes step (d) jointly adjusting the weight control components associated with at least two of the plurality of antenna elements in response to the signal quality metric of the received beacon frame; and (e) repeating the step (d) until an optimum signal quality metric is achieved.
The method further includes step (f) independently adjusting the weight control components in response to the signal quality metric of the received beacon frame; and (g) repeating the step (e) until the determined signal quality metric of the combined received beacon frame reaches an optimum value.
According to another embodiment of the present invention there is provided a mobile station operating within a wireless local area network (WLAN). The mobile station comprises: a plurality of antenna elements; a plurality of weight control components coupled to the plurality of antenna elements; a combiner coupled to the plurality of antenna elements;
and at least one transceiver coupled to the combiner. The mobile station includes a controller coupled to the at least one transceiver and to the plurality of weight control components for setting the plurality of weight control components. The setting of the plurality of weight control components comprises: (a) receiving a beacon frame from each of the plurality of antenna elements; (b) combining the received beacon frame detected from each of the plurality of antenna elements to produce a combined received beacon frame; and (c) determining a signal quality metric for the combined received beacon frame.
The setting further comprises step (d) jointly adjusting the weight control components associated with at least two of the plurality of antenna elements in response to the signal quality metric of the received beacon frame; (e) repeating the step (d) until an optimum signal quality metric is achieved; (f) independently adjusting the weight control components in response to the signal quality metric of the received beacon frame; and (g) repeating the step (e) until the determined signal quality metric of the combined received beacon frame reaches an optimum value.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
FIG. 1 illustrates a cell of a wireless communications system.
FIG. 2a illustrates one configuration of an antenna apparatus used by a mobile station.
FIG. 2b illustrates another configuration of an antenna apparatus.
FIG. 3 is a flow cllart of the processing steps perfomled to optimally set the weight value for the signal transmitted from or received by each antenna elenlent.
FIG. 4 is a flow chart of steps performed by a perturbational algorithm to optinlally determine the arrangement of antenna elements.
FIG. 5 illustrates a flow diagrain for a perturbational computational algorithm for computing the weights to be assigned to each anteinia element.
FIG. 6 illustrates another antenna embodiment.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
A description of preferred embodiments of the invention follows.
FIG. 1 illustrates a typical wireless communication system such as a CDMA cellular comniunication system. The ce1150 represents a pliysical area in which mobile stations 60-1 through 60-3 communicate with a centrally located base station 160. One or more mobile stations 60 are equipped with an antenna 100 configured according to the present invention. The mobile stations 60 are provided with wireless data and/or voice seivices by the system operator and can connect devices such as, for example, laptop computers, portable computers, personal digital assistants (PDAs) or the lilce through base station 160 to a network 75, which can be the public switched telephone networlc (PSTN), a packet switched computer network, such as the Internet, a public data network or a private intranet. The base station 160 can communicate with the network 75 over any number of different available communications protocols such as primary rate ISDN, or other LAPD based protocols such as IS-634 or V5.2, or even TCP/IP if network 75 is a packet based Ethernet network such as the Internet. The stations 60 are typically mobile in nature and may travel from one location to another while communicating with the base station 160.
As the stations leave one cell and enter another, the communications link is handed off from the base station of the exiting cell to the base station of the entering cell.
FIG. 1 illustrates one base station 160 and three mobile stations 60 in a ce1150 by way of example only and for ease of description of the invention. The invention is applicable to systems in which there are typically many more mobile stations 60 communicating with one or more base stations 160 in an individual cell, such as the cell 50.
It is also to be understood by those skilled in the art that FIG. 1 may be a standard cellular type communications system employing signaling schemes such as a CDMA, TDMA, GSM or others in which the radio channels are assigned to carry data and/or voice between the base stations 160 and stations 60. In a preferred embodiment, FIG.
1 is a CDMA-like system, using code division multiplexing principles such as those defined in the IS-95B standards for the air interface.
But it should be understood that FIG. 1 is also representative of other types of wireless systems. For example, a Wireless Local Area Network (WLAN) operating in accordance with IEEE Standard 802.11 b has one or more control base stations 160 (also referred to correctly in the 802.11 parlance as Access Points). WLANs are similar to cellular systems in that each base station 160 services a number of remote mobile stations 60 that are active at the same time. So, the reference to base station 160 here is equally applicable to WLAN Access Points.
FIG. 2a illustrates one configuration of an antenna apparatus used by a mobile station.
FIG. 2b illustrates another configuration of an antenna apparatus.
FIG. 3 is a flow cllart of the processing steps perfomled to optimally set the weight value for the signal transmitted from or received by each antenna elenlent.
FIG. 4 is a flow chart of steps performed by a perturbational algorithm to optinlally determine the arrangement of antenna elements.
FIG. 5 illustrates a flow diagrain for a perturbational computational algorithm for computing the weights to be assigned to each anteinia element.
FIG. 6 illustrates another antenna embodiment.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
A description of preferred embodiments of the invention follows.
FIG. 1 illustrates a typical wireless communication system such as a CDMA cellular comniunication system. The ce1150 represents a pliysical area in which mobile stations 60-1 through 60-3 communicate with a centrally located base station 160. One or more mobile stations 60 are equipped with an antenna 100 configured according to the present invention. The mobile stations 60 are provided with wireless data and/or voice seivices by the system operator and can connect devices such as, for example, laptop computers, portable computers, personal digital assistants (PDAs) or the lilce through base station 160 to a network 75, which can be the public switched telephone networlc (PSTN), a packet switched computer network, such as the Internet, a public data network or a private intranet. The base station 160 can communicate with the network 75 over any number of different available communications protocols such as primary rate ISDN, or other LAPD based protocols such as IS-634 or V5.2, or even TCP/IP if network 75 is a packet based Ethernet network such as the Internet. The stations 60 are typically mobile in nature and may travel from one location to another while communicating with the base station 160.
As the stations leave one cell and enter another, the communications link is handed off from the base station of the exiting cell to the base station of the entering cell.
FIG. 1 illustrates one base station 160 and three mobile stations 60 in a ce1150 by way of example only and for ease of description of the invention. The invention is applicable to systems in which there are typically many more mobile stations 60 communicating with one or more base stations 160 in an individual cell, such as the cell 50.
It is also to be understood by those skilled in the art that FIG. 1 may be a standard cellular type communications system employing signaling schemes such as a CDMA, TDMA, GSM or others in which the radio channels are assigned to carry data and/or voice between the base stations 160 and stations 60. In a preferred embodiment, FIG.
1 is a CDMA-like system, using code division multiplexing principles such as those defined in the IS-95B standards for the air interface.
But it should be understood that FIG. 1 is also representative of other types of wireless systems. For example, a Wireless Local Area Network (WLAN) operating in accordance with IEEE Standard 802.11 b has one or more control base stations 160 (also referred to correctly in the 802.11 parlance as Access Points). WLANs are similar to cellular systems in that each base station 160 services a number of remote mobile stations 60 that are active at the same time. So, the reference to base station 160 here is equally applicable to WLAN Access Points.
The invention provides the niobile stations 60 with an antenna 100 that provides directional reception of forward link radio signals transmitted froin the base station 160, as well as directional transmission of reverse linlc signals, via a process called beam forming, from the mobile stations 60 to the base station 160.
This concept is illustrated in FIG. 1 by the example beam patterns 71 through that extend outwardly from each mobile station 60 inore or less in a direction for best propagation toward the base station 160. By being able to direct transmission more or less toward the base station 160, and by being able to directively receive signals originating more or less from the location of the base station 160, the antenna apparatus 100 reduces the effects of intercell interference and multipath fading for the mobile stations 60. Moreover, since the transmission beam patterns 71, 72 and 73 extend outward in the direction of the base station 160 but are attenuated in most otller directions, less power is required for transmission of effective communications signals from the mobile stations 60-1, 60-2 and 60-3 to the base station 160.
FIG. 2a illustrates a detailed view of a mobile station 60 and an associated antenna apparatus 100 configured according to one embodiinent of the present invention. Antenna apparatus 100 includes a platform or housing 110 upon which are mounted a plurality of antenna eleinents 101-1, 101-2, ..., 101-n (collectively referred to herein as the antenna elements 101). Witliin housing 110, the antenna apparatus 100 includes weight control components 111-1, 111-2, ..., 111-n (collectively, the weights 111) for adjusting the amplitude, phase or both the amplitude and phase of the signal received by or transniitted from each respective element 101-1, 101-2, ..., 101-n, a bi-directional summation network or splitter/combiner 120, a transceiver 130, and a controller 140, which are all interconnected via a bus 135. As illustrated, the antenna apparatus 100 is coupled via the transceiver 130 to a laptop coniputer 150 (not drawn to scale). The antenna 100 provides the laptop computer 150 with wireless data communication services via forward linlc signals 180 transmitted from the base station 160 and reverse link signals 170 transmitted to the base station 160.
This concept is illustrated in FIG. 1 by the example beam patterns 71 through that extend outwardly from each mobile station 60 inore or less in a direction for best propagation toward the base station 160. By being able to direct transmission more or less toward the base station 160, and by being able to directively receive signals originating more or less from the location of the base station 160, the antenna apparatus 100 reduces the effects of intercell interference and multipath fading for the mobile stations 60. Moreover, since the transmission beam patterns 71, 72 and 73 extend outward in the direction of the base station 160 but are attenuated in most otller directions, less power is required for transmission of effective communications signals from the mobile stations 60-1, 60-2 and 60-3 to the base station 160.
FIG. 2a illustrates a detailed view of a mobile station 60 and an associated antenna apparatus 100 configured according to one embodiinent of the present invention. Antenna apparatus 100 includes a platform or housing 110 upon which are mounted a plurality of antenna eleinents 101-1, 101-2, ..., 101-n (collectively referred to herein as the antenna elements 101). Witliin housing 110, the antenna apparatus 100 includes weight control components 111-1, 111-2, ..., 111-n (collectively, the weights 111) for adjusting the amplitude, phase or both the amplitude and phase of the signal received by or transniitted from each respective element 101-1, 101-2, ..., 101-n, a bi-directional summation network or splitter/combiner 120, a transceiver 130, and a controller 140, which are all interconnected via a bus 135. As illustrated, the antenna apparatus 100 is coupled via the transceiver 130 to a laptop coniputer 150 (not drawn to scale). The antenna 100 provides the laptop computer 150 with wireless data communication services via forward linlc signals 180 transmitted from the base station 160 and reverse link signals 170 transmitted to the base station 160.
In one embodiment, each antenna element 101 may be disposed on the surface of the housing 110. For example, if the housing is a rectangular box, four elements 101 may be respectively positioned at locations corresponding to the corners of a rectangle (in one embodiment the rectangle is a square), and a fifth antenna element 101 at a location corresponding to the center of the rectangle. The distance between each element 101 is great enough so that the relationship between a signal received by more than one element 101 will be out of phase with other elements that also receive the same signal, assuming all elements 101 have the same setting for their respective weight control components 111. However, n can be any convenient number.
The weight control components 111 are both dependently and independently adjustable to affect the directionality of signals to be transmitted and/or received to or from the station (i.e., laptop computer 150 in this example).
By properly adjusting the weight control components (i.e., the weights) for each element 101 during signal transmission, a composite beam is formed that is positionally directed toward the base station 160. That is, the optimal arrangement for the weight control components for sending a reverse link signal 170 from the antenna 100 is a setting for each antenna element 101 that creates a directional reverse link signal beam former. The result is an antenna 100 that directs a stronger reverse link signal pattern in the direction of the intended receiver base station 160, reducing the likelihood that an unintended base station in an adjacent cell will also receive the reverse link signal 170.
The weight coritrol component settings used for transmission of signals over the reverse link 170 also cause the elements 101 to optimally receive forward link signals 180 transmitted from the base station 160, and reduce the reception of signals from other adjacent base stations. Due to the controllable nature and the independence of the weight control components for each antenna element 101, only forward link signals 180 arriving from a direction that is more or less in the location of the base station 160 are optimally received. The elements 101 naturally reject other signals that are not transmitted from directions proximate the intended forward link signals 180. In other words, a directional antenna is formed by adjusting the weight control components of each element 101.
It should be understood that there are alternate embodiments of the antenna elements 101 and transceiver 130. As shown in FIG. 2b, a plurality of antenna elements 101-1, 101-2, ..., 101-m again are associated with a like plurality of weight control components 111-1, 111-2, ..., 111-m. There are in this embodiment a different plurality of transceivers 130-1, 130-2,..., 130-n. The splitter/ combiner 120 connects to all transceivers 130 in this embodiment. In one such an embodiment, n=m so that there is a transceiver 130 associated with each element 101. However, other RF combiner/ splitters 125 might be used to support arrangements where n does not equal m, by combining signals associated with one or more antenna elements 101.
Regardless of whether the FIG. 2a or FIG. 2b embodiment is used, the weight control component 111 settings, in accordance with the teachings of the present invention, are first established by a coarse adjustment wherein all weight control components 111 are simultaneously adjusted to point the antenna beam. In lieu of adjusting the weight control components I 11, a plurality of weight vectors are used. Each weight vector represents an antenna directional angle and each contains a value or element, one element for each weight control component 111. As the weight control components are adjusted (or vector elements applied to each weight control component), a signal quality metric (e.g.
signal to noise ratio, power or signal to interference ratio (Eo/Io)) is monitored to find the optimum (i.e., minimum or maximum, dependent on the specific metric) signal quality metric value.
Since all weight control components 111 are simultaneously adjusted in this coarse mode, the antenna beam shape remains unchanged while the antenna beam rotates through azimuth angles.
Once the optimum signal quality metric value has been identified, the weight control components 111 are decoupled from each other and then independently adjusted to fine tune the antenna beam pattern.
This inventive technique of coarse adjustment followed by fine adjustment reduces the time required to achieve an optimal antenna beam pattern. Absent the coarse adjustment step, the independent adjustment of each of the weight control components 111 involves the adjustment of independent parameters (representing, more generally, n degrees of freedom) and therefore, takes longer to converge to an optimum beam pattern. Beginning the process with only one degree of freedom, by simultaneously changing all of the weight control components 111, achieves a generally optimal antenna pattern quickly; to be followed by the fine adjustment process for determining the optimal antenna pattern. The coarse adjustment/fine adjustment process converges more quickly to the final optimal antenna beam pattern than prior art techniques.
The summation network 120 is coupled to the signal terminal S, of each weight control component 111. During transmission, the summation network 120 provides a reverse link signal to each of the weight control components 111. The weight control components 111 affect the correction of the reverse link signal by imparting a weight (in one embodiment, a phase shift) to the input signal, as determined by a control input signal P to each weight control component 111. Differentiating the reverse link signals 170 transmitted from each element 101 causes constructive or destructive interference with the signals transmitted from the other elements. In this manner, the interfering signals combine to for6l a strong composite beam for the reverse link signals 170 in the desired direction. The imparted weight provided to each antenna element 101 determines the direction in which the composite beam is transmitted.
The weight control components 111 used for transmission from each antenna element 101, also provide a similar effect on a forward link signal 180 that is received from the base station 160. That is, as each element 101 receives a signal 180 from the base station 160, (prior to the adjustment of the weight control components 111) the respective received signals are out of phase with each other due to the physical separation of the elements 101 on the housing 110. However, each received signal is shifted by the weight control components 111. The adjustment brings each signal in phase with the other received signals 180.
Accordingly, the signal quality metric associated with the composite received signal, produced by the summation network 120, is maximized.
The weight control components 111 are both dependently and independently adjustable to affect the directionality of signals to be transmitted and/or received to or from the station (i.e., laptop computer 150 in this example).
By properly adjusting the weight control components (i.e., the weights) for each element 101 during signal transmission, a composite beam is formed that is positionally directed toward the base station 160. That is, the optimal arrangement for the weight control components for sending a reverse link signal 170 from the antenna 100 is a setting for each antenna element 101 that creates a directional reverse link signal beam former. The result is an antenna 100 that directs a stronger reverse link signal pattern in the direction of the intended receiver base station 160, reducing the likelihood that an unintended base station in an adjacent cell will also receive the reverse link signal 170.
The weight coritrol component settings used for transmission of signals over the reverse link 170 also cause the elements 101 to optimally receive forward link signals 180 transmitted from the base station 160, and reduce the reception of signals from other adjacent base stations. Due to the controllable nature and the independence of the weight control components for each antenna element 101, only forward link signals 180 arriving from a direction that is more or less in the location of the base station 160 are optimally received. The elements 101 naturally reject other signals that are not transmitted from directions proximate the intended forward link signals 180. In other words, a directional antenna is formed by adjusting the weight control components of each element 101.
It should be understood that there are alternate embodiments of the antenna elements 101 and transceiver 130. As shown in FIG. 2b, a plurality of antenna elements 101-1, 101-2, ..., 101-m again are associated with a like plurality of weight control components 111-1, 111-2, ..., 111-m. There are in this embodiment a different plurality of transceivers 130-1, 130-2,..., 130-n. The splitter/ combiner 120 connects to all transceivers 130 in this embodiment. In one such an embodiment, n=m so that there is a transceiver 130 associated with each element 101. However, other RF combiner/ splitters 125 might be used to support arrangements where n does not equal m, by combining signals associated with one or more antenna elements 101.
Regardless of whether the FIG. 2a or FIG. 2b embodiment is used, the weight control component 111 settings, in accordance with the teachings of the present invention, are first established by a coarse adjustment wherein all weight control components 111 are simultaneously adjusted to point the antenna beam. In lieu of adjusting the weight control components I 11, a plurality of weight vectors are used. Each weight vector represents an antenna directional angle and each contains a value or element, one element for each weight control component 111. As the weight control components are adjusted (or vector elements applied to each weight control component), a signal quality metric (e.g.
signal to noise ratio, power or signal to interference ratio (Eo/Io)) is monitored to find the optimum (i.e., minimum or maximum, dependent on the specific metric) signal quality metric value.
Since all weight control components 111 are simultaneously adjusted in this coarse mode, the antenna beam shape remains unchanged while the antenna beam rotates through azimuth angles.
Once the optimum signal quality metric value has been identified, the weight control components 111 are decoupled from each other and then independently adjusted to fine tune the antenna beam pattern.
This inventive technique of coarse adjustment followed by fine adjustment reduces the time required to achieve an optimal antenna beam pattern. Absent the coarse adjustment step, the independent adjustment of each of the weight control components 111 involves the adjustment of independent parameters (representing, more generally, n degrees of freedom) and therefore, takes longer to converge to an optimum beam pattern. Beginning the process with only one degree of freedom, by simultaneously changing all of the weight control components 111, achieves a generally optimal antenna pattern quickly; to be followed by the fine adjustment process for determining the optimal antenna pattern. The coarse adjustment/fine adjustment process converges more quickly to the final optimal antenna beam pattern than prior art techniques.
The summation network 120 is coupled to the signal terminal S, of each weight control component 111. During transmission, the summation network 120 provides a reverse link signal to each of the weight control components 111. The weight control components 111 affect the correction of the reverse link signal by imparting a weight (in one embodiment, a phase shift) to the input signal, as determined by a control input signal P to each weight control component 111. Differentiating the reverse link signals 170 transmitted from each element 101 causes constructive or destructive interference with the signals transmitted from the other elements. In this manner, the interfering signals combine to for6l a strong composite beam for the reverse link signals 170 in the desired direction. The imparted weight provided to each antenna element 101 determines the direction in which the composite beam is transmitted.
The weight control components 111 used for transmission from each antenna element 101, also provide a similar effect on a forward link signal 180 that is received from the base station 160. That is, as each element 101 receives a signal 180 from the base station 160, (prior to the adjustment of the weight control components 111) the respective received signals are out of phase with each other due to the physical separation of the elements 101 on the housing 110. However, each received signal is shifted by the weight control components 111. The adjustment brings each signal in phase with the other received signals 180.
Accordingly, the signal quality metric associated with the composite received signal, produced by the summation network 120, is maximized.
To optimally establish the weight value for each of the weight control components 111, weight control values are provided by the controller 140. Generally, in the preferred embodiment, the controller 140 determines these optimum weights during idle periods when the laptop computer 150 is neither transmitting nor receiving payload or informational data via the antenna 100. When the station 60 is operating in this idle state, a predetermined signal, that is transmitted from the base station 160 and is received at each antenna element 101 serves as the basis for adjusting the weight control components 111 to optimize reception of such as by maximizing the received signal energy or other link signal quality metric.
The exact type of predetermined signal 190 used to adjust the weight control components 111 depends upon the exact type of system 100. In the case of a CDMA cellular system the predetermined signal 190 can be a forward link pilot signal or access channel signal. In the case of a WLAN system 100, the predetermined signal 190 can be a beacon frame, a Barker sequence, or similar predetermined bit pattern. Other suitable predetermined signals 190 can be preambles, training sequences, or similar signals that can be known, apriori, at the receiver.
The controller 140 thus determines and sets an optimal weight for each weight control component 111, to optimize reception of the forward link pilot signal 190. When the antenna 100 enters an active mode for transmission or reception of signals between the base station 160 and the laptop 150, the weight as set by each of the weight control components 111 remains as set during the previous idle state.
The exact type of predetermined signal 190 used to adjust the weight control components 111 depends upon the exact type of system 100. In the case of a CDMA cellular system the predetermined signal 190 can be a forward link pilot signal or access channel signal. In the case of a WLAN system 100, the predetermined signal 190 can be a beacon frame, a Barker sequence, or similar predetermined bit pattern. Other suitable predetermined signals 190 can be preambles, training sequences, or similar signals that can be known, apriori, at the receiver.
The controller 140 thus determines and sets an optimal weight for each weight control component 111, to optimize reception of the forward link pilot signal 190. When the antenna 100 enters an active mode for transmission or reception of signals between the base station 160 and the laptop 150, the weight as set by each of the weight control components 111 remains as set during the previous idle state.
Before a detailed description of the weight-setting computation as performed by the controller 140 is given, it should be understood that the invention is based in part on the observation that the location of the base station 160 relative to any one mobile station (i.e., laptop 150) is approximately circumferential in nature. That is, if a circle is drawn around a mobile station 60 and base station locations are assumed to have a minimum of one degree of granularity, the base station 160 can be located at 360 possible angular locations. The combination of the n weights, (one value for each of the n weight control components 111), optimizes the antenna pattern at an angular sector within the 360 circle.
Minimal sector widths are attainable with the process according to the present invention for establishing the weight values.
In accordance with the teachings of the present invention, a two-step process is employed to determine the optimal weights. First, the controller 140 simultaneously adjusts all of the weight control components 111 through a series of values. For example, all of the weight control components 111 can be simultaneously adjusted so that the central axis of the antenna beam pattern steps through five degree intervals, resulting in 72 different angular positions around the 360 degree circle. The control signal input to each of the weight control components 111 for changing the weights to scan the antenna beam can be read from memory locations within the controller 140. The index into the memory locations is the desired antenna beam angle and the output is five weights to be applied to the P terminal of each of the weight control components 111 for pointing the antenna beam in the desired direction. At each beam location the response of the transceiver 130 to the pilot signal is determined. In one embodiment of the present invention the antenna rescan process is performed while the station 60 is in the idle state. The scanning process can also be performed on a known set of data transmitted from the base station 160 during the active mode. After incrementing through all directional angles in the 360 degree circle (or a predetermined sector of the circle if the base station 160 is known to be in a certain direction relative to the mobile station 60) and detecting the receiver response for each directional angle, the weight combination (i.e., one for each of the weight control components 111) having the optimal receiver response, as measured by any one of a number of receiver metrics (for instance, maximum signal to noise ratio, bit error rate, the ratio of energy per bit, Eb, or energy per chip, Ec, to total interference, Io or to total noise, No) is determined and the weight control components 111 are reset to those weight values.
Next, the weight control components 111 are decoupled and each is independently controlled by inputting independent weight values to the P
terminal of each, until the optimum signal quality metric is identified. This fine adjustment approach eventually determines a weight for each of the weight control components 111 that produces the optimum signal quality metric, as determined from the received pilot signal.
It should also be noted that although FIG. 2a illustrates a splitter/combiner 120 (operating in conjunction with the transceiver 130) through which all signals received by and transmitted from the elements 101 pass, this element is not a necessarily required according to the teachings of the present invention. In another embodiment, as shown in FIG. 2b, each element 101 can be connected directly to a transceiver 130 for receiving and transmitting signals, where the weight control components 111 are interposed between each element and its corresponding transceiver. Each transceiver can individually determine the signal quality metric of the signal received at its associated element and the five (or n in the more general case) resulting signal quality metrics provided as an input to the controller 140 for determining a combined signal quality metric and in response thereto establishing the weights for each element as disclosed herein. In essence, the teachings of the present invention can be applied to a plurality of cooperating antenna elements for locating the optimum directional angle for the antenna, independent of the specific processing methodology for the signals received and transmitted through each of the elements.
FIG. 3 shows steps 302 through 307 performed by the controller 140 according to one embodiment of the invention for achieving the optimum signal quality metric (i.e., the optimum antenna directional angle) during the coarse adjustment phase. In lieu of the controller 140, a general purpose microprocessor or a dedicated microprocessor within the station 60 can be programmed to execute the processes set forth in FIGS. 3 and 4. As discussed above, the process of scanning the antenna beam angles, in both the coarse and fine modes, can be perfonned while the station 60 is in the idle state. In order to determine the optimal coarse weight values for the weight control components 111, steps 302 through 306 are performed during idle periods of data reception and transmission by using the pilot signal 190 transmitted from the base station 160. However, in another embodiment of the present invention, the rescan process can be performed using known data transmitted from the base station 160 during the active operational state of the station 60. The signal quality metrics are determined for the known data and the coarse and fine adjustment processes are performed as set forth in FIGS. 3, 4 and 5.
At a step 302, the controller 140 determines that the station 60 is in the idle state, such as by detecting the absence of certain forward link signals 180 or the presence of the predetennined signal 190. At a step 303 weights are established for each of the weight control components 111 and in response the antenna beam pattern is pointed in a first or relative 0 degree azimuth angle. The step 303 is the first step in a rescan loop that executes once for each directional angle assumed by the antenna 100, in search of the optimum directional angle. As the loop executes, the weights associated with each of the weight control components 111 are modified so that the antenna 100 scans to a different angular direction with every pass through the loop. The weights may, for example, be precalculated and stored in a table, with one weight for each element 101 for each possible antenna angle.
In other words, step 303 programs each weight control component 111 for a first angle, which may be conceptualized as angle 0 in a 360 degree circle surrounding the mobile station 60. At a step 304 the station 60 (or in another embodiment, the laptop computer 150) determines a signal quality metric for the received predetermined (e.g., pilot) signal 190, as output from the summation network 120.
The measurement in step 304 reflects how well each antenna element 101 detected the received predetermined signal 190 based upon the current set of weights applied at the step 303. The signal metric value is stored at the step 304.
The metric may, for example, be a link quality metric such as bit error rate or signal energy to noise energy per chip (Ec/No).
The step 305 then returns processing to the step 303 where the weights are jointly modified by the controller 140 to change the directional angle of the antenna 100. In one embodiment, this adjustment is accomplished by selecting another weight vector from among the stored vectors, and using the vector elements as the weight values. In one embodiment, this adjustment is accomplished by selecting another weight vector from among the stored vectors, and using the vector elements as the weight values. The steps 302 through 305 repeat until the antenna 100 has been scanned through the desired directional angles, and a signal quality metric value measured for each angle. Once the step 305 determines that all desired directional angles have been scanned, a step determines the optimum set of weights as determined by the setting that produced the optimum (largest or smallest, as the dictated by the chosen signal metric) received signal metric value. A step 307 then programs the weight control components 111 with the set of weights that was determined to produce the best result.
Once the coarse adjustment process of FIG. 3 is complete and the weight values set for the best signal quality metric at the step 307, a step 308 indicates that processing moves to the fine weight adjustment process of FIG. 4., The fine adjustment process of FIG. 4 begins at a step 401 where one of the weight control components 111 is selected for holding at a constant value while the weights of the weight control components are varied. At a step 402 the remaining weight control components are modified. In one embodiment the weight control components are adjusted or incremented in accordance with a predetermined algorithm or in fixed incremental values. The use and characteristics of an algorithm for optimizing a metric where there are N
degrees of freedom are well known in the art. Then the quality signal metric is measured and saved at a step 406. The saved value is associated with the unique weights set at the steps 401 and 402. The process continues executing through the loop formed by the steps 402, 406 and 408, adjusting the four weight control components each time processing moves through the step 402. The granularity of the weight adjustments executed at the step 402 is determinable by the system user. After all the possible settings for the varied weight control components have been utilized, the decision step 408 returns a positive response and the process proceeds to the decision step 410, where a negative response is obtained until all the weight control components have been selected at the step 401. Therefore, another weight control component is selected to hold at a constant value (the step 401) and the others are adjusted as the process executes through the steps 402, 406 and 408 again.
An affirmative response from the decision step 410 moves processing to a step 412, where the best setting for the weight control components 111 is determined. Recall that at the step 406 the predetermined signal metrics were measured and saved. Therefore, processing at the step 412 involves checking the saved signal quality metric values to identify the optimum value. At a step 414, the weights for the weight control components 111 associated with the best or optimum signal metric value are determined and the weight control components 111 are adjusted in accordance with those values. At this point, both the coarse and fme adjustment processes have been cornpleted and the antenna pattern determined by the weights at the. step 414 is an optimum pattern.
During periods of idle time, the FIGS. 3 and 4 processes can be repeated to compensate for the movement of the antenna 100 relative to the direction and orientation of the base station 160 and changes in the physical environment that cause changes in the interference pattern. In addition, the antenna 100 may be optimized during transmission of information signals by processing through the FIGS. 3 and 4 flowcharts, when known data is received by the station 60 so that the signal metric values of the received signal are suitable for comparison and identification of the optimum signal quality metric.
FIG. 5 illustrates a schematic of electronic components for implementing a perturbational algorithm to determine optimal weights for each antenna element 101, as required for the FIGS. 3 and 4 processes.
For example, if n=5, the algorithm fixes a value for four of the five unknown, optimum weights W[i], e.g. W[2] through W[5]. The algorithm perturbs the system and observes the response, adapting to find the optimum arrangement for the unfixed weight, e.g. W[1]. The measured link quality metric, in this case E,/Io, is fed to a first gain block G1. The control loop gain setting, G, of the input is fed to a second gain block G2. A first fast clock, CLKI, which alternates from a value of "1" to a value of "-1" is inverted by Il and fed to a first multiplier Ml.
The other input of multiplier M1 is fed from the gain block G2.
The output of Ml is fed to a multiplier M3 together with the output of the first gain block G1. An integrator NI measures an average level and provides this value to the latch L. A slow clock CLK2, typically alternating at a rate which varies between "1" and "0" and is much slower than CLK1 (by at least 100 times) drives the latch clock C. The output of the latch L is summed by summation block S with the non-inverted output from M2. The result, W[i], is a value which tends to seek a localized minimal value of the function to be optimized.
The process shown in FIG. 5 is then repeated by setting the first weight to W[1] and then determining W[2] by varying W[3] to W[5] in accordance with the FIG. 5 process. The process continues to find the optimum value for each of the five unknown weight settings.
It should be understood that the process is similar when the number of antenna elements is not equal to five.
Minimal sector widths are attainable with the process according to the present invention for establishing the weight values.
In accordance with the teachings of the present invention, a two-step process is employed to determine the optimal weights. First, the controller 140 simultaneously adjusts all of the weight control components 111 through a series of values. For example, all of the weight control components 111 can be simultaneously adjusted so that the central axis of the antenna beam pattern steps through five degree intervals, resulting in 72 different angular positions around the 360 degree circle. The control signal input to each of the weight control components 111 for changing the weights to scan the antenna beam can be read from memory locations within the controller 140. The index into the memory locations is the desired antenna beam angle and the output is five weights to be applied to the P terminal of each of the weight control components 111 for pointing the antenna beam in the desired direction. At each beam location the response of the transceiver 130 to the pilot signal is determined. In one embodiment of the present invention the antenna rescan process is performed while the station 60 is in the idle state. The scanning process can also be performed on a known set of data transmitted from the base station 160 during the active mode. After incrementing through all directional angles in the 360 degree circle (or a predetermined sector of the circle if the base station 160 is known to be in a certain direction relative to the mobile station 60) and detecting the receiver response for each directional angle, the weight combination (i.e., one for each of the weight control components 111) having the optimal receiver response, as measured by any one of a number of receiver metrics (for instance, maximum signal to noise ratio, bit error rate, the ratio of energy per bit, Eb, or energy per chip, Ec, to total interference, Io or to total noise, No) is determined and the weight control components 111 are reset to those weight values.
Next, the weight control components 111 are decoupled and each is independently controlled by inputting independent weight values to the P
terminal of each, until the optimum signal quality metric is identified. This fine adjustment approach eventually determines a weight for each of the weight control components 111 that produces the optimum signal quality metric, as determined from the received pilot signal.
It should also be noted that although FIG. 2a illustrates a splitter/combiner 120 (operating in conjunction with the transceiver 130) through which all signals received by and transmitted from the elements 101 pass, this element is not a necessarily required according to the teachings of the present invention. In another embodiment, as shown in FIG. 2b, each element 101 can be connected directly to a transceiver 130 for receiving and transmitting signals, where the weight control components 111 are interposed between each element and its corresponding transceiver. Each transceiver can individually determine the signal quality metric of the signal received at its associated element and the five (or n in the more general case) resulting signal quality metrics provided as an input to the controller 140 for determining a combined signal quality metric and in response thereto establishing the weights for each element as disclosed herein. In essence, the teachings of the present invention can be applied to a plurality of cooperating antenna elements for locating the optimum directional angle for the antenna, independent of the specific processing methodology for the signals received and transmitted through each of the elements.
FIG. 3 shows steps 302 through 307 performed by the controller 140 according to one embodiment of the invention for achieving the optimum signal quality metric (i.e., the optimum antenna directional angle) during the coarse adjustment phase. In lieu of the controller 140, a general purpose microprocessor or a dedicated microprocessor within the station 60 can be programmed to execute the processes set forth in FIGS. 3 and 4. As discussed above, the process of scanning the antenna beam angles, in both the coarse and fine modes, can be perfonned while the station 60 is in the idle state. In order to determine the optimal coarse weight values for the weight control components 111, steps 302 through 306 are performed during idle periods of data reception and transmission by using the pilot signal 190 transmitted from the base station 160. However, in another embodiment of the present invention, the rescan process can be performed using known data transmitted from the base station 160 during the active operational state of the station 60. The signal quality metrics are determined for the known data and the coarse and fine adjustment processes are performed as set forth in FIGS. 3, 4 and 5.
At a step 302, the controller 140 determines that the station 60 is in the idle state, such as by detecting the absence of certain forward link signals 180 or the presence of the predetennined signal 190. At a step 303 weights are established for each of the weight control components 111 and in response the antenna beam pattern is pointed in a first or relative 0 degree azimuth angle. The step 303 is the first step in a rescan loop that executes once for each directional angle assumed by the antenna 100, in search of the optimum directional angle. As the loop executes, the weights associated with each of the weight control components 111 are modified so that the antenna 100 scans to a different angular direction with every pass through the loop. The weights may, for example, be precalculated and stored in a table, with one weight for each element 101 for each possible antenna angle.
In other words, step 303 programs each weight control component 111 for a first angle, which may be conceptualized as angle 0 in a 360 degree circle surrounding the mobile station 60. At a step 304 the station 60 (or in another embodiment, the laptop computer 150) determines a signal quality metric for the received predetermined (e.g., pilot) signal 190, as output from the summation network 120.
The measurement in step 304 reflects how well each antenna element 101 detected the received predetermined signal 190 based upon the current set of weights applied at the step 303. The signal metric value is stored at the step 304.
The metric may, for example, be a link quality metric such as bit error rate or signal energy to noise energy per chip (Ec/No).
The step 305 then returns processing to the step 303 where the weights are jointly modified by the controller 140 to change the directional angle of the antenna 100. In one embodiment, this adjustment is accomplished by selecting another weight vector from among the stored vectors, and using the vector elements as the weight values. In one embodiment, this adjustment is accomplished by selecting another weight vector from among the stored vectors, and using the vector elements as the weight values. The steps 302 through 305 repeat until the antenna 100 has been scanned through the desired directional angles, and a signal quality metric value measured for each angle. Once the step 305 determines that all desired directional angles have been scanned, a step determines the optimum set of weights as determined by the setting that produced the optimum (largest or smallest, as the dictated by the chosen signal metric) received signal metric value. A step 307 then programs the weight control components 111 with the set of weights that was determined to produce the best result.
Once the coarse adjustment process of FIG. 3 is complete and the weight values set for the best signal quality metric at the step 307, a step 308 indicates that processing moves to the fine weight adjustment process of FIG. 4., The fine adjustment process of FIG. 4 begins at a step 401 where one of the weight control components 111 is selected for holding at a constant value while the weights of the weight control components are varied. At a step 402 the remaining weight control components are modified. In one embodiment the weight control components are adjusted or incremented in accordance with a predetermined algorithm or in fixed incremental values. The use and characteristics of an algorithm for optimizing a metric where there are N
degrees of freedom are well known in the art. Then the quality signal metric is measured and saved at a step 406. The saved value is associated with the unique weights set at the steps 401 and 402. The process continues executing through the loop formed by the steps 402, 406 and 408, adjusting the four weight control components each time processing moves through the step 402. The granularity of the weight adjustments executed at the step 402 is determinable by the system user. After all the possible settings for the varied weight control components have been utilized, the decision step 408 returns a positive response and the process proceeds to the decision step 410, where a negative response is obtained until all the weight control components have been selected at the step 401. Therefore, another weight control component is selected to hold at a constant value (the step 401) and the others are adjusted as the process executes through the steps 402, 406 and 408 again.
An affirmative response from the decision step 410 moves processing to a step 412, where the best setting for the weight control components 111 is determined. Recall that at the step 406 the predetermined signal metrics were measured and saved. Therefore, processing at the step 412 involves checking the saved signal quality metric values to identify the optimum value. At a step 414, the weights for the weight control components 111 associated with the best or optimum signal metric value are determined and the weight control components 111 are adjusted in accordance with those values. At this point, both the coarse and fme adjustment processes have been cornpleted and the antenna pattern determined by the weights at the. step 414 is an optimum pattern.
During periods of idle time, the FIGS. 3 and 4 processes can be repeated to compensate for the movement of the antenna 100 relative to the direction and orientation of the base station 160 and changes in the physical environment that cause changes in the interference pattern. In addition, the antenna 100 may be optimized during transmission of information signals by processing through the FIGS. 3 and 4 flowcharts, when known data is received by the station 60 so that the signal metric values of the received signal are suitable for comparison and identification of the optimum signal quality metric.
FIG. 5 illustrates a schematic of electronic components for implementing a perturbational algorithm to determine optimal weights for each antenna element 101, as required for the FIGS. 3 and 4 processes.
For example, if n=5, the algorithm fixes a value for four of the five unknown, optimum weights W[i], e.g. W[2] through W[5]. The algorithm perturbs the system and observes the response, adapting to find the optimum arrangement for the unfixed weight, e.g. W[1]. The measured link quality metric, in this case E,/Io, is fed to a first gain block G1. The control loop gain setting, G, of the input is fed to a second gain block G2. A first fast clock, CLKI, which alternates from a value of "1" to a value of "-1" is inverted by Il and fed to a first multiplier Ml.
The other input of multiplier M1 is fed from the gain block G2.
The output of Ml is fed to a multiplier M3 together with the output of the first gain block G1. An integrator NI measures an average level and provides this value to the latch L. A slow clock CLK2, typically alternating at a rate which varies between "1" and "0" and is much slower than CLK1 (by at least 100 times) drives the latch clock C. The output of the latch L is summed by summation block S with the non-inverted output from M2. The result, W[i], is a value which tends to seek a localized minimal value of the function to be optimized.
The process shown in FIG. 5 is then repeated by setting the first weight to W[1] and then determining W[2] by varying W[3] to W[5] in accordance with the FIG. 5 process. The process continues to find the optimum value for each of the five unknown weight settings.
It should be understood that the process is similar when the number of antenna elements is not equal to five.
Alternatively, in the coarse mode instead of incrementally varying the weight setting for each antenna element 101, the weight for each element can be stored in a table of vectors, each vector having n elements representing the n weight control settings for the weight control components 101. The values in each vector can be computed in advance based upon the angle of arrival of the received predetermined signals. That is, the values for each antenna element are determined according to the direction in which the base station is located in relation to the mobile station. In operation, the angle of arrival can be used as an index into the table of vectors and the weight control components set to the weight represented by the elements of the selected vector. By using a table with vectors, only the single angle of arrival calculation needs to be performed to properly set the coarse weights for each antenna element 101. The weight adjustment process of FIG. 4 then executes.
The antenna apparatus in preferred embodiments of the invention is inexpensive to construct and greatly increases the capacity in a CDMA
interference limited system. That is, the number of active stations within a single cell in a CDMA system is limited in part by the number of frequencies available for use and by signal interference limitations that occur as the number of frequencies in use increases. As more frequencies become active within a single cell, interference imposes maximum limitations on the number of users who can effectively communicate with the base station. Intercell interference also contributes as a limiting factor to cell capacity. Given the ability of the present invention to converge quickly, by using the coarse and fine processes, provides quick and accurate adaptation of a mobile station to changes in the angle and location relative to the base station 160.
Since this invention adaptively eliminates interference from adjacent cells and selectively directs transmission and reception of signals from each mobile unit equipped with the invention to and from the base station, an increase in the number of users per cell is realized. Moreover, the invention reduces the required transmit power for each mobile station by providing an extended directed beam towards the base station.
Alternative physical embodiments of the antenna include a four element antenna wherein three of the elements are positioned at comers of an equilateral triangular plane and are arranged orthogonally and extend outward from that plane. The fourth element is similarly situated but is located in the center of the triangle.
Further, the teachings of the present inventions are applicable to an antenna comprising a plurality of elements, where less than all of the elements are active elements, i.e., for radiating or receiving a signal where the other elements serve as parasitic elements to reflect, redirect or absorb some portions of the emitted signal to advantageously shape the transmitted beam in the transmit mode and similarly advantageously affect the receive beam pattern. The elements can be operative in either the active or parasitic mode as determined by an element controller.
FIG. 6 illustrates such an antenna embodiment including both parasitic and active elements. Parasitic elements 500 and 502 are connected respectively to terminations 504 and 506. An active element 508 is connected to conventional receiving circuitry 510, such as that shown in FIG. 2a. Although FIG. 5 illustrates two parasitic elements and a single active element, it is known by those skilled in the art that the fundamentals associated with FIG. 6 are extendable to n parasitic elements and m active elements. In one embodiment, for instance, the teachings of the present invention can be applied to parasitic elements one each arranged at the four corners of a rectangle and the active element at approximately the rectangle center.
In operation, a signal is received at each of the parasitic elements 500 and 502 as shown. The signal is then carried to the terminations 504, 506, respectively, and reflected back therefrom through the elements 500 and 502.
The terminations 504 and 506 comprise any one of the following: a phase shifting device, a weight control component (such as the weight control components 111 of FIGS. 2a or 2b) an impedance termination and a switch. The terminations 504 and 506 control both the amplitude and phase, only the phase, or only the amplitude of the signal input thereto, and thereby produce a reflected signal having a certain relationship (i.e., amplitude and phase characteristics) with respect to the received signal. The reflected signals are radiated from the elements 500 and 502, and effectively combined upon receipt at the active element 508.
It is seen that the FIG. 6 embodiment accomplishes these three primary objectives of an antenna array: receiving the signal at an element, imparting a phase or amplitude shift to the received signal and combining the received signals.
Although the FIG. 6 configuration has been explained in the receiving mode, it is known by those skilled in the art that in accordance with the antenna reciprocity theorem a like a function is achieved in the transmit mode.
While this invention has been particularly shown and described with references to preferred embodiments, those skilled in the art will realize that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. For example, there can be alternative mechanisms for determining the proper weights for each antenna element, such as storing weights in.a linked list or a database instead of a table. Moreover, those skilled in the art of radio frequency measurement techniques understand there are various ways to detect the angle of arrival and signal quality metrics of a signal, such as the received predetermined signal. These mechanisms for determining the signal angle of arrival and signal quality metrics are meant to be contemplated for use by this invention. Once the location is then known, the proper weights for weight control components may be quickly obtained. Such equivalents are intended to be encompassed within the scope of the claims.
The antenna apparatus in preferred embodiments of the invention is inexpensive to construct and greatly increases the capacity in a CDMA
interference limited system. That is, the number of active stations within a single cell in a CDMA system is limited in part by the number of frequencies available for use and by signal interference limitations that occur as the number of frequencies in use increases. As more frequencies become active within a single cell, interference imposes maximum limitations on the number of users who can effectively communicate with the base station. Intercell interference also contributes as a limiting factor to cell capacity. Given the ability of the present invention to converge quickly, by using the coarse and fine processes, provides quick and accurate adaptation of a mobile station to changes in the angle and location relative to the base station 160.
Since this invention adaptively eliminates interference from adjacent cells and selectively directs transmission and reception of signals from each mobile unit equipped with the invention to and from the base station, an increase in the number of users per cell is realized. Moreover, the invention reduces the required transmit power for each mobile station by providing an extended directed beam towards the base station.
Alternative physical embodiments of the antenna include a four element antenna wherein three of the elements are positioned at comers of an equilateral triangular plane and are arranged orthogonally and extend outward from that plane. The fourth element is similarly situated but is located in the center of the triangle.
Further, the teachings of the present inventions are applicable to an antenna comprising a plurality of elements, where less than all of the elements are active elements, i.e., for radiating or receiving a signal where the other elements serve as parasitic elements to reflect, redirect or absorb some portions of the emitted signal to advantageously shape the transmitted beam in the transmit mode and similarly advantageously affect the receive beam pattern. The elements can be operative in either the active or parasitic mode as determined by an element controller.
FIG. 6 illustrates such an antenna embodiment including both parasitic and active elements. Parasitic elements 500 and 502 are connected respectively to terminations 504 and 506. An active element 508 is connected to conventional receiving circuitry 510, such as that shown in FIG. 2a. Although FIG. 5 illustrates two parasitic elements and a single active element, it is known by those skilled in the art that the fundamentals associated with FIG. 6 are extendable to n parasitic elements and m active elements. In one embodiment, for instance, the teachings of the present invention can be applied to parasitic elements one each arranged at the four corners of a rectangle and the active element at approximately the rectangle center.
In operation, a signal is received at each of the parasitic elements 500 and 502 as shown. The signal is then carried to the terminations 504, 506, respectively, and reflected back therefrom through the elements 500 and 502.
The terminations 504 and 506 comprise any one of the following: a phase shifting device, a weight control component (such as the weight control components 111 of FIGS. 2a or 2b) an impedance termination and a switch. The terminations 504 and 506 control both the amplitude and phase, only the phase, or only the amplitude of the signal input thereto, and thereby produce a reflected signal having a certain relationship (i.e., amplitude and phase characteristics) with respect to the received signal. The reflected signals are radiated from the elements 500 and 502, and effectively combined upon receipt at the active element 508.
It is seen that the FIG. 6 embodiment accomplishes these three primary objectives of an antenna array: receiving the signal at an element, imparting a phase or amplitude shift to the received signal and combining the received signals.
Although the FIG. 6 configuration has been explained in the receiving mode, it is known by those skilled in the art that in accordance with the antenna reciprocity theorem a like a function is achieved in the transmit mode.
While this invention has been particularly shown and described with references to preferred embodiments, those skilled in the art will realize that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. For example, there can be alternative mechanisms for determining the proper weights for each antenna element, such as storing weights in.a linked list or a database instead of a table. Moreover, those skilled in the art of radio frequency measurement techniques understand there are various ways to detect the angle of arrival and signal quality metrics of a signal, such as the received predetermined signal. These mechanisms for determining the signal angle of arrival and signal quality metrics are meant to be contemplated for use by this invention. Once the location is then known, the proper weights for weight control components may be quickly obtained. Such equivalents are intended to be encompassed within the scope of the claims.
Claims (24)
1. A method for setting optimal weight control component arrangements for a plurality of antenna elements of a transceiver operating in a wireless local area network (WLAN), the method comprising the steps of:
(a) receiving a beacon frame from each of the plurality of antenna elements;
(b) combining the received beacon frame detected from each of the plurality of antenna elements to produce a combined received beacon frame;
(c) determining a signal quality metric for the combined received beacon frame;
(d) jointly adjusting the weight control components associated with at least two of the plurality of antenna elements in response to the signal quality metric of the received beacon frame;
(e) repeating the step (d) until an optimum signal quality metric is achieved;
(f) independently adjusting the weight control components in response to the signal quality metric of the received beacon frame; and (g) repeating the step (e) until the determined signal quality metric of the combined received beacon frame reaches an optimum value.
(a) receiving a beacon frame from each of the plurality of antenna elements;
(b) combining the received beacon frame detected from each of the plurality of antenna elements to produce a combined received beacon frame;
(c) determining a signal quality metric for the combined received beacon frame;
(d) jointly adjusting the weight control components associated with at least two of the plurality of antenna elements in response to the signal quality metric of the received beacon frame;
(e) repeating the step (d) until an optimum signal quality metric is achieved;
(f) independently adjusting the weight control components in response to the signal quality metric of the received beacon frame; and (g) repeating the step (e) until the determined signal quality metric of the combined received beacon frame reaches an optimum value.
2. The method of claim 1 wherein the signal quality metric is the ratio of received signal energy to interference.
3. The method of claim 1 wherein the signal quality metric is the ratio of received signal energy to thermal noise.
4. The method of claim 1 wherein the signal quality metric is received signal power.
5. The method of claim 1 wherein each weight control component includes a phase shifter.
6. The method of claim 1 wherein each weight control component includes an amplifier and a phase shifter.
7. The method of claim 1 wherein each weight control component includes an electromagnetic coupler.
8. The method of claim 1 wherein the steps (d) and (f) include adjusting the amplitude, phase or the amplitude and the phase imparted to the output signal from the plurality of antenna elements.
9. The method of claim 1 wherein the optimum value of the signal quality metric exceeds a predetermined value.
10. The method of claim 1 wherein step (b) of combining further comprises, after adjusting weight control components for at least two specific received beacon frames, a step of combining the specific received beacon frame prior to combining other received beacon frames.
11. The method of claim 1 wherein the adjustment of the weight control components occurs when the transceiver is in an active state.
12. The method of claim 1 wherein the weight control components are jointly adjustable in a first mode and independently adjustable in a second mode to optimize the signal received at the antenna elements by reducing the interference caused by signals that are not transmitted from an intended access point.
13. The method of claim 1 wherein the weight control components are jointly adjustable in a first mode and independently adjustable in a second mode to optimize a signal transmitted to a selected access point via the antenna elements by reducing the interference caused to other access points.
14. A mobile station operating within a wireless local area network (WLAN) comprising:
a plurality of antenna elements;
a plurality of weight control components coupled to said plurality of antenna elements;
a combiner coupled to said plurality of antenna elements; and at least one transceiver coupled to said combiner; and a controller coupled to said at least one transceiver and to said plurality of weight control components for setting said plurality of weight control components, the setting comprising:
(a) receiving a beacon frame from each of the plurality of antenna elements;
(b) combining the received beacon frame detected from each of the plurality of antenna elements to produce a combined received beacon frame;
(c) determining a signal quality metric for the combined received beacon frame;
(d) jointly adjusting the weight control components associated with at least two of the plurality of antenna elements in response to the signal quality metric of the received beacon frame;
(e) repeating the step (d) until an optimum signal quality metric is achieved;
(f) independently adjusting the weight control components in response to the signal quality metric of the received beacon frame; and (g) repeating the step (e) until the determined signal quality metric of the combined received beacon frame reaches an optimum value.
a plurality of antenna elements;
a plurality of weight control components coupled to said plurality of antenna elements;
a combiner coupled to said plurality of antenna elements; and at least one transceiver coupled to said combiner; and a controller coupled to said at least one transceiver and to said plurality of weight control components for setting said plurality of weight control components, the setting comprising:
(a) receiving a beacon frame from each of the plurality of antenna elements;
(b) combining the received beacon frame detected from each of the plurality of antenna elements to produce a combined received beacon frame;
(c) determining a signal quality metric for the combined received beacon frame;
(d) jointly adjusting the weight control components associated with at least two of the plurality of antenna elements in response to the signal quality metric of the received beacon frame;
(e) repeating the step (d) until an optimum signal quality metric is achieved;
(f) independently adjusting the weight control components in response to the signal quality metric of the received beacon frame; and (g) repeating the step (e) until the determined signal quality metric of the combined received beacon frame reaches an optimum value.
15. The mobile station of claim 14 wherein the signal quality metric is the ratio of received signal energy to interference.
16. The mobile station of claim 14 wherein the signal quality metric is the ratio of received signal energy to thermal noise.
17. The mobile station of claim 14 wherein the signal quality metric is received signal power.
18. The mobile station of claim 14 wherein each weight control component comprises a phase shifter.
19. The mobile station of claim 14 wherein each weight control component comprises an amplifier and a phase shifter coupled thereto.
20. The mobile station of claim 14 wherein each weight control component comprises an electromagnetic coupler.
21. The mobile station of claim 14 wherein the steps (b) and (d) performed by said controller comprise adjusting the amplitude, phase or the amplitude and the phase imparted to the output signal from said plurality of antenna elements.
22. The mobile station of claim 14 wherein the optimum value of the signal quality metric exceeds a predetermined value.
23. The mobile station of claim 14 wherein said weight control components are jointly adjustable in a first mode and independently adjustable in a second mode to optimize the signal received at said plurality of antenna elements by reducing the interference caused by signals that are not transmitted from an intended access point.
24. The mobile station of claim 14 wherein said weight control components are jointly adjustable in a first mode and independently adjustable in a second mode to optimize the signal transmitted to a selected access point via said plurality of antenna elements by reducing the interference caused to other access points.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/282,928 | 2002-10-28 | ||
US10/282,928 US6933887B2 (en) | 1998-09-21 | 2002-10-28 | Method and apparatus for adapting antenna array using received predetermined signal |
PCT/US2003/034215 WO2004040692A1 (en) | 2002-10-28 | 2003-10-28 | Method and apparatus for adapting antenna array using received predetermined signal |
Publications (2)
Publication Number | Publication Date |
---|---|
CA2503042A1 CA2503042A1 (en) | 2004-05-13 |
CA2503042C true CA2503042C (en) | 2010-01-12 |
Family
ID=32228792
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002503042A Expired - Fee Related CA2503042C (en) | 2002-10-28 | 2003-10-28 | Method and apparatus for adapting antenna array using received predetermined signal |
Country Status (11)
Country | Link |
---|---|
US (2) | US6933887B2 (en) |
EP (1) | EP1559169A4 (en) |
JP (1) | JP2006504354A (en) |
KR (1) | KR100817620B1 (en) |
CN (1) | CN1708876A (en) |
AU (1) | AU2003285061A1 (en) |
CA (1) | CA2503042C (en) |
MX (1) | MXPA05004603A (en) |
NO (1) | NO20052572L (en) |
TW (1) | TW200509458A (en) |
WO (1) | WO2004040692A1 (en) |
Families Citing this family (248)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7076228B1 (en) * | 1999-11-10 | 2006-07-11 | Rilling Kenneth F | Interference reduction for multiple signals |
US7006040B2 (en) | 2000-12-21 | 2006-02-28 | Hitachi America, Ltd. | Steerable antenna and receiver interface for terrestrial broadcast |
US7509096B2 (en) * | 2002-07-26 | 2009-03-24 | Broadcom Corporation | Wireless access point setup and management within wireless local area network |
US7394796B2 (en) * | 2002-07-26 | 2008-07-01 | Broadcom Corporation | Wireless access point service coverage area management |
US7042394B2 (en) | 2002-08-14 | 2006-05-09 | Skipper Wireless Inc. | Method and system for determining direction of transmission using multi-facet antenna |
US7480486B1 (en) | 2003-09-10 | 2009-01-20 | Sprint Spectrum L.P. | Wireless repeater and method for managing air interface communications |
US7406295B1 (en) | 2003-09-10 | 2008-07-29 | Sprint Spectrum L.P. | Method for dynamically directing a wireless repeater |
US20050105505A1 (en) * | 2003-11-07 | 2005-05-19 | Eran Fishler | Transceiver for a wireless local area network having a sparse preamble data sequence |
TWI256207B (en) * | 2003-11-24 | 2006-06-01 | Interdigital Tech Corp | Method and apparatus for utilizing a directional beam antenna in a wireless transmit/receive unit |
US7460082B2 (en) * | 2003-12-30 | 2008-12-02 | Intel Corporation | Sectored antenna systems for WLAN |
US7308264B2 (en) * | 2004-02-05 | 2007-12-11 | Interdigital Technology Corporation | Method for identifying pre-candidate cells for a mobile unit operating with a switched beam antenna in a wireless communication system, and corresponding system |
US7295811B2 (en) * | 2004-02-05 | 2007-11-13 | Interdigital Technology Corporation | Method for performing measurements for handoff of a mobile unit operating with a switched beam antenna in a wireless communication system, and corresponding system |
US7340254B2 (en) * | 2004-02-05 | 2008-03-04 | Interdigital Technology Corporation | Measurement opportunities for a mobile unit operating with a switched beam antenna in a CDMA system |
US7274936B2 (en) * | 2004-02-06 | 2007-09-25 | Interdigital Technology Corporation | Method and apparatus for measuring channel quality using a smart antenna in a wireless transmit/receive unit |
US7324817B2 (en) * | 2004-02-07 | 2008-01-29 | Interdigital Technology Corporation | Wireless communication method and apparatus for selecting and reselecting cells based on measurements performed using directional beams and an omni-directional beam pattern |
US7457545B2 (en) * | 2004-02-12 | 2008-11-25 | Northrop Grumman Corporation | Process for controlling a Hartmann wavefront sensor (WFS) in an adaptive optic (AO) system |
US7333830B2 (en) * | 2004-02-26 | 2008-02-19 | Quorum Systems, Inc. | Method and apparatus for synchronizing WLAN in a multi-mode radio system |
US7200376B2 (en) * | 2004-03-17 | 2007-04-03 | Interdigital Technology Corporation | Method for steering smart antenna beams for a WLAN using MAC layer functions |
US7289828B2 (en) * | 2004-03-17 | 2007-10-30 | Interdigital Technology Corporation | Method for steering a smart antenna for a WLAN using a periodic re-scan |
US7312750B2 (en) * | 2004-03-19 | 2007-12-25 | Comware, Inc. | Adaptive beam-forming system using hierarchical weight banks for antenna array in wireless communication system |
US7725080B2 (en) * | 2004-03-31 | 2010-05-25 | The Invention Science Fund I, Llc | Mote networks having directional antennas |
US8335814B2 (en) | 2004-03-31 | 2012-12-18 | The Invention Science Fund I, Llc | Transmission of aggregated mote-associated index data |
WO2005099288A2 (en) * | 2004-03-31 | 2005-10-20 | Searete Llc | Using mote-associated indexes |
US7457834B2 (en) * | 2004-07-30 | 2008-11-25 | Searete, Llc | Aggregation and retrieval of network sensor data |
US7536388B2 (en) * | 2004-03-31 | 2009-05-19 | Searete, Llc | Data storage for distributed sensor networks |
WO2005099289A2 (en) * | 2004-03-31 | 2005-10-20 | Searete Llc | Mote-associated index creation |
US7389295B2 (en) | 2004-06-25 | 2008-06-17 | Searete Llc | Using federated mote-associated logs |
US9261383B2 (en) | 2004-07-30 | 2016-02-16 | Triplay, Inc. | Discovery of occurrence-data |
US9062992B2 (en) | 2004-07-27 | 2015-06-23 | TriPlay Inc. | Using mote-associated indexes |
US7366544B2 (en) | 2004-03-31 | 2008-04-29 | Searete, Llc | Mote networks having directional antennas |
US8200744B2 (en) | 2004-03-31 | 2012-06-12 | The Invention Science Fund I, Llc | Mote-associated index creation |
US8161097B2 (en) | 2004-03-31 | 2012-04-17 | The Invention Science Fund I, Llc | Aggregating mote-associated index data |
US8275824B2 (en) | 2004-03-31 | 2012-09-25 | The Invention Science Fund I, Llc | Occurrence data detection and storage for mote networks |
US7599696B2 (en) * | 2004-06-25 | 2009-10-06 | Searete, Llc | Frequency reuse techniques in mote-appropriate networks |
US7929914B2 (en) | 2004-03-31 | 2011-04-19 | The Invention Science Fund I, Llc | Mote networks using directional antenna techniques |
US20060079285A1 (en) * | 2004-03-31 | 2006-04-13 | Jung Edward K Y | Transmission of mote-associated index data |
US7317898B2 (en) * | 2004-03-31 | 2008-01-08 | Searete Llc | Mote networks using directional antenna techniques |
US8346846B2 (en) | 2004-05-12 | 2013-01-01 | The Invention Science Fund I, Llc | Transmission of aggregated mote-associated log data |
US7941188B2 (en) | 2004-03-31 | 2011-05-10 | The Invention Science Fund I, Llc | Occurrence data detection and storage for generalized sensor networks |
WO2006016402A1 (en) * | 2004-08-10 | 2006-02-16 | Mitsubishi Denki Kabushiki Kaisha | Base station and mobile unit of mobile communication system, and azimuth determining method |
US7081597B2 (en) * | 2004-09-03 | 2006-07-25 | The Esab Group, Inc. | Electrode and electrode holder with threaded connection |
KR100666985B1 (en) * | 2004-09-30 | 2007-01-10 | 삼성전자주식회사 | Method and apparatus for calibrating in adaptive array antenna system |
US7567807B2 (en) * | 2005-04-21 | 2009-07-28 | Kyocera Wireless Corp. | Apparatus and method for performing handoff with a mobile station having a smart antenna |
DE602005017484D1 (en) * | 2005-07-13 | 2009-12-17 | Chigusa Tadaaki | Method and system for generating a transmission direction by means of a multi-faceted antenna |
WO2007009972A1 (en) * | 2005-07-20 | 2007-01-25 | Sony Ericsson Mobile Communications Ab | Antenna control arrangement and method |
EP1746735A1 (en) * | 2005-07-20 | 2007-01-24 | Sony Ericsson Mobile Communications AB | Antenna control arrangement and method |
US7907971B2 (en) | 2005-08-22 | 2011-03-15 | Airgain, Inc. | Optimized directional antenna system |
US9084260B2 (en) | 2005-10-26 | 2015-07-14 | Intel Corporation | Systems for communicating using multiple frequency bands in a wireless network |
US8072946B2 (en) * | 2006-03-30 | 2011-12-06 | Intel Corporation | Coordinated transmissions in wireless networks |
US7680518B2 (en) * | 2006-03-31 | 2010-03-16 | Interdigital Technology Corporation | Deviation based antenna control algorithm for an access point |
US7778149B1 (en) | 2006-07-27 | 2010-08-17 | Tadaaki Chigusa | Method and system to providing fast access channel |
US7606528B2 (en) * | 2006-11-10 | 2009-10-20 | Northrop Grumman Corporation | Distributed conformal adaptive antenna array for SATCOM using decision direction |
US20080117865A1 (en) * | 2006-11-17 | 2008-05-22 | Li Guoqing C | Communication in a wireless network using multiple antennae |
US8160096B1 (en) | 2006-12-06 | 2012-04-17 | Tadaaki Chigusa | Method and system for reserving bandwidth in time-division multiplexed networks |
CN101595654B (en) * | 2006-12-19 | 2014-05-07 | 艾尔加因公司 | Optimized directional mimo antenna system |
US20080172322A1 (en) | 2007-01-17 | 2008-07-17 | Steidlmayer Pete | Method for scheduling future orders on an electronic commodity trading system |
TWI355112B (en) * | 2007-06-14 | 2011-12-21 | Asustek Comp Inc | Method and system for setting smart antenna |
KR100959038B1 (en) * | 2007-06-14 | 2010-05-20 | 삼성전자주식회사 | Apparatus and method for parameter rollback in self configurable broadband wireless communication system |
US7978134B2 (en) | 2007-08-13 | 2011-07-12 | Samsung Electronics Co., Ltd. | System and method for efficient transmit and receive beamforming protocol with heterogeneous antenna configuration |
US8051037B2 (en) * | 2008-01-25 | 2011-11-01 | Samsung Electronics Co., Ltd. | System and method for pseudorandom permutation for interleaving in wireless communications |
US8165595B2 (en) * | 2008-01-25 | 2012-04-24 | Samsung Electronics Co., Ltd. | System and method for multi-stage antenna training of beamforming vectors |
US8280445B2 (en) * | 2008-02-13 | 2012-10-02 | Samsung Electronics Co., Ltd. | System and method for antenna training of beamforming vectors by selective use of beam level training |
US20090231196A1 (en) * | 2008-03-11 | 2009-09-17 | Huaning Niu | Mmwave wpan communication system with fast adaptive beam tracking |
CN102124334B (en) * | 2008-05-06 | 2017-05-31 | 高露洁-棕榄公司 | The method of the effect that measurement component is produced to cytoactive oxygen class material |
US8478204B2 (en) * | 2008-07-14 | 2013-07-02 | Samsung Electronics Co., Ltd. | System and method for antenna training of beamforming vectors having reuse of directional information |
JP5214033B2 (en) * | 2008-10-29 | 2013-06-19 | マーベル ワールド トレード リミテッド | Highly efficient and flexible beamforming sector sweep for transmission in multi-antenna communication devices |
US8730873B2 (en) * | 2008-11-04 | 2014-05-20 | Nokia Corporation | Asymmetric beam steering protocol |
US8934855B2 (en) * | 2008-11-12 | 2015-01-13 | Apple Inc. | Antenna auto-configuration |
US8289901B2 (en) * | 2009-03-17 | 2012-10-16 | Cisco Technology, Inc. | Pinning and cascading avoidance in dynamic channel assignment for wireless LANS |
US20100241588A1 (en) * | 2009-03-17 | 2010-09-23 | Andrew Busby | System and method for determining confidence levels for a market depth in a commodities market |
US9178593B1 (en) | 2009-04-21 | 2015-11-03 | Marvell International Ltd. | Directional channel measurement and interference avoidance |
EP2955859A1 (en) * | 2009-06-02 | 2015-12-16 | Technische Universität Dresden | Method for controlling a spatial diversity transmitter and receiver structure |
TWI400968B (en) * | 2009-07-28 | 2013-07-01 | Chunghwa Telecom Co Ltd | Method of Operational Efficiency Analysis of Mobile Network Base Station |
US20110032143A1 (en) * | 2009-08-05 | 2011-02-10 | Yulan Sun | Fixed User Terminal for Inclined Orbit Satellite Operation |
US8488499B2 (en) * | 2011-01-04 | 2013-07-16 | General Electric Company | System and method of enhanced quality of service of wireless communication based on redundant signal reception on two or more antenna diversity inputs |
US8761100B2 (en) | 2011-10-11 | 2014-06-24 | CBF Networks, Inc. | Intelligent backhaul system |
US10051643B2 (en) | 2011-08-17 | 2018-08-14 | Skyline Partners Technology Llc | Radio with interference measurement during a blanking interval |
US8422540B1 (en) | 2012-06-21 | 2013-04-16 | CBF Networks, Inc. | Intelligent backhaul radio with zero division duplexing |
US8238318B1 (en) | 2011-08-17 | 2012-08-07 | CBF Networks, Inc. | Intelligent backhaul radio |
US9713019B2 (en) | 2011-08-17 | 2017-07-18 | CBF Networks, Inc. | Self organizing backhaul radio |
US8467363B2 (en) | 2011-08-17 | 2013-06-18 | CBF Networks, Inc. | Intelligent backhaul radio and antenna system |
US8989762B1 (en) | 2013-12-05 | 2015-03-24 | CBF Networks, Inc. | Advanced backhaul services |
US8928542B2 (en) | 2011-08-17 | 2015-01-06 | CBF Networks, Inc. | Backhaul radio with an aperture-fed antenna assembly |
US10716111B2 (en) | 2011-08-17 | 2020-07-14 | Skyline Partners Technology Llc | Backhaul radio with adaptive beamforming and sample alignment |
US8502733B1 (en) | 2012-02-10 | 2013-08-06 | CBF Networks, Inc. | Transmit co-channel spectrum sharing |
US8385305B1 (en) * | 2012-04-16 | 2013-02-26 | CBF Networks, Inc | Hybrid band intelligent backhaul radio |
US10764891B2 (en) | 2011-08-17 | 2020-09-01 | Skyline Partners Technology Llc | Backhaul radio with advanced error recovery |
US10708918B2 (en) | 2011-08-17 | 2020-07-07 | Skyline Partners Technology Llc | Electronic alignment using signature emissions for backhaul radios |
US10548132B2 (en) | 2011-08-17 | 2020-01-28 | Skyline Partners Technology Llc | Radio with antenna array and multiple RF bands |
US9474080B2 (en) | 2011-08-17 | 2016-10-18 | CBF Networks, Inc. | Full duplex backhaul radio with interference measurement during a blanking interval |
US8982772B2 (en) | 2011-08-17 | 2015-03-17 | CBF Networks, Inc. | Radio transceiver with improved radar detection |
JP6000631B2 (en) * | 2012-05-10 | 2016-10-05 | オリンパス株式会社 | Wireless communication apparatus, wireless communication system, antenna control method, and program |
EP2900001B1 (en) * | 2012-09-21 | 2019-03-20 | Mitsubishi Electric Corporation | Wireless communication device, wireless communication system and wireless communication method |
US10009065B2 (en) | 2012-12-05 | 2018-06-26 | At&T Intellectual Property I, L.P. | Backhaul link for distributed antenna system |
US9113347B2 (en) | 2012-12-05 | 2015-08-18 | At&T Intellectual Property I, Lp | Backhaul link for distributed antenna system |
US9525524B2 (en) | 2013-05-31 | 2016-12-20 | At&T Intellectual Property I, L.P. | Remote distributed antenna system |
US9999038B2 (en) | 2013-05-31 | 2018-06-12 | At&T Intellectual Property I, L.P. | Remote distributed antenna system |
US8897697B1 (en) | 2013-11-06 | 2014-11-25 | At&T Intellectual Property I, Lp | Millimeter-wave surface-wave communications |
JP2015159421A (en) * | 2014-02-24 | 2015-09-03 | パナソニック株式会社 | Radio communication device and directivity control method |
US9692101B2 (en) | 2014-08-26 | 2017-06-27 | At&T Intellectual Property I, L.P. | Guided wave couplers for coupling electromagnetic waves between a waveguide surface and a surface of a wire |
US9768833B2 (en) | 2014-09-15 | 2017-09-19 | At&T Intellectual Property I, L.P. | Method and apparatus for sensing a condition in a transmission medium of electromagnetic waves |
US10063280B2 (en) | 2014-09-17 | 2018-08-28 | At&T Intellectual Property I, L.P. | Monitoring and mitigating conditions in a communication network |
US9615269B2 (en) | 2014-10-02 | 2017-04-04 | At&T Intellectual Property I, L.P. | Method and apparatus that provides fault tolerance in a communication network |
US9685992B2 (en) | 2014-10-03 | 2017-06-20 | At&T Intellectual Property I, L.P. | Circuit panel network and methods thereof |
US9503189B2 (en) | 2014-10-10 | 2016-11-22 | At&T Intellectual Property I, L.P. | Method and apparatus for arranging communication sessions in a communication system |
US9762289B2 (en) | 2014-10-14 | 2017-09-12 | At&T Intellectual Property I, L.P. | Method and apparatus for transmitting or receiving signals in a transportation system |
US9973299B2 (en) | 2014-10-14 | 2018-05-15 | At&T Intellectual Property I, L.P. | Method and apparatus for adjusting a mode of communication in a communication network |
US9520945B2 (en) | 2014-10-21 | 2016-12-13 | At&T Intellectual Property I, L.P. | Apparatus for providing communication services and methods thereof |
US9653770B2 (en) | 2014-10-21 | 2017-05-16 | At&T Intellectual Property I, L.P. | Guided wave coupler, coupling module and methods for use therewith |
US9769020B2 (en) | 2014-10-21 | 2017-09-19 | At&T Intellectual Property I, L.P. | Method and apparatus for responding to events affecting communications in a communication network |
US9577306B2 (en) | 2014-10-21 | 2017-02-21 | At&T Intellectual Property I, L.P. | Guided-wave transmission device and methods for use therewith |
US9627768B2 (en) | 2014-10-21 | 2017-04-18 | At&T Intellectual Property I, L.P. | Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith |
US9780834B2 (en) | 2014-10-21 | 2017-10-03 | At&T Intellectual Property I, L.P. | Method and apparatus for transmitting electromagnetic waves |
US9312919B1 (en) | 2014-10-21 | 2016-04-12 | At&T Intellectual Property I, Lp | Transmission device with impairment compensation and methods for use therewith |
JP5944086B1 (en) * | 2014-11-04 | 2016-07-05 | 三菱電機株式会社 | Antenna control apparatus, antenna adjustment method, and distributed antenna system |
US9954287B2 (en) | 2014-11-20 | 2018-04-24 | At&T Intellectual Property I, L.P. | Apparatus for converting wireless signals and electromagnetic waves and methods thereof |
US9800327B2 (en) | 2014-11-20 | 2017-10-24 | At&T Intellectual Property I, L.P. | Apparatus for controlling operations of a communication device and methods thereof |
US9544006B2 (en) | 2014-11-20 | 2017-01-10 | At&T Intellectual Property I, L.P. | Transmission device with mode division multiplexing and methods for use therewith |
US9461706B1 (en) | 2015-07-31 | 2016-10-04 | At&T Intellectual Property I, Lp | Method and apparatus for exchanging communication signals |
US9742462B2 (en) | 2014-12-04 | 2017-08-22 | At&T Intellectual Property I, L.P. | Transmission medium and communication interfaces and methods for use therewith |
US10009067B2 (en) | 2014-12-04 | 2018-06-26 | At&T Intellectual Property I, L.P. | Method and apparatus for configuring a communication interface |
US10340573B2 (en) | 2016-10-26 | 2019-07-02 | At&T Intellectual Property I, L.P. | Launcher with cylindrical coupling device and methods for use therewith |
US9997819B2 (en) | 2015-06-09 | 2018-06-12 | At&T Intellectual Property I, L.P. | Transmission medium and method for facilitating propagation of electromagnetic waves via a core |
US10243784B2 (en) | 2014-11-20 | 2019-03-26 | At&T Intellectual Property I, L.P. | System for generating topology information and methods thereof |
KR102284069B1 (en) * | 2015-01-26 | 2021-07-30 | 한국전자통신연구원 | Smart antenna system and method for improving receiving performance thereof |
US10144036B2 (en) | 2015-01-30 | 2018-12-04 | At&T Intellectual Property I, L.P. | Method and apparatus for mitigating interference affecting a propagation of electromagnetic waves guided by a transmission medium |
CN107409367B (en) * | 2015-02-20 | 2020-12-01 | 瑞典爱立信有限公司 | Radio unit for controlling power levels of spatially separated transceivers in a wireless communication network and method therein |
US9876570B2 (en) | 2015-02-20 | 2018-01-23 | At&T Intellectual Property I, Lp | Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith |
US9749013B2 (en) | 2015-03-17 | 2017-08-29 | At&T Intellectual Property I, L.P. | Method and apparatus for reducing attenuation of electromagnetic waves guided by a transmission medium |
US10224981B2 (en) | 2015-04-24 | 2019-03-05 | At&T Intellectual Property I, Lp | Passive electrical coupling device and methods for use therewith |
US9705561B2 (en) | 2015-04-24 | 2017-07-11 | At&T Intellectual Property I, L.P. | Directional coupling device and methods for use therewith |
US9948354B2 (en) | 2015-04-28 | 2018-04-17 | At&T Intellectual Property I, L.P. | Magnetic coupling device with reflective plate and methods for use therewith |
US9793954B2 (en) | 2015-04-28 | 2017-10-17 | At&T Intellectual Property I, L.P. | Magnetic coupling device and methods for use therewith |
US9748626B2 (en) | 2015-05-14 | 2017-08-29 | At&T Intellectual Property I, L.P. | Plurality of cables having different cross-sectional shapes which are bundled together to form a transmission medium |
US9871282B2 (en) | 2015-05-14 | 2018-01-16 | At&T Intellectual Property I, L.P. | At least one transmission medium having a dielectric surface that is covered at least in part by a second dielectric |
US9490869B1 (en) | 2015-05-14 | 2016-11-08 | At&T Intellectual Property I, L.P. | Transmission medium having multiple cores and methods for use therewith |
US10650940B2 (en) | 2015-05-15 | 2020-05-12 | At&T Intellectual Property I, L.P. | Transmission medium having a conductive material and methods for use therewith |
US9917341B2 (en) | 2015-05-27 | 2018-03-13 | At&T Intellectual Property I, L.P. | Apparatus and method for launching electromagnetic waves and for modifying radial dimensions of the propagating electromagnetic waves |
US10812174B2 (en) | 2015-06-03 | 2020-10-20 | At&T Intellectual Property I, L.P. | Client node device and methods for use therewith |
US10103801B2 (en) | 2015-06-03 | 2018-10-16 | At&T Intellectual Property I, L.P. | Host node device and methods for use therewith |
US9912381B2 (en) | 2015-06-03 | 2018-03-06 | At&T Intellectual Property I, Lp | Network termination and methods for use therewith |
US9866309B2 (en) | 2015-06-03 | 2018-01-09 | At&T Intellectual Property I, Lp | Host node device and methods for use therewith |
US9913139B2 (en) | 2015-06-09 | 2018-03-06 | At&T Intellectual Property I, L.P. | Signal fingerprinting for authentication of communicating devices |
US10142086B2 (en) | 2015-06-11 | 2018-11-27 | At&T Intellectual Property I, L.P. | Repeater and methods for use therewith |
US9608692B2 (en) | 2015-06-11 | 2017-03-28 | At&T Intellectual Property I, L.P. | Repeater and methods for use therewith |
US9820146B2 (en) | 2015-06-12 | 2017-11-14 | At&T Intellectual Property I, L.P. | Method and apparatus for authentication and identity management of communicating devices |
US9667317B2 (en) | 2015-06-15 | 2017-05-30 | At&T Intellectual Property I, L.P. | Method and apparatus for providing security using network traffic adjustments |
US9509415B1 (en) | 2015-06-25 | 2016-11-29 | At&T Intellectual Property I, L.P. | Methods and apparatus for inducing a fundamental wave mode on a transmission medium |
US9865911B2 (en) | 2015-06-25 | 2018-01-09 | At&T Intellectual Property I, L.P. | Waveguide system for slot radiating first electromagnetic waves that are combined into a non-fundamental wave mode second electromagnetic wave on a transmission medium |
US9640850B2 (en) | 2015-06-25 | 2017-05-02 | At&T Intellectual Property I, L.P. | Methods and apparatus for inducing a non-fundamental wave mode on a transmission medium |
US10033108B2 (en) | 2015-07-14 | 2018-07-24 | At&T Intellectual Property I, L.P. | Apparatus and methods for generating an electromagnetic wave having a wave mode that mitigates interference |
US10170840B2 (en) | 2015-07-14 | 2019-01-01 | At&T Intellectual Property I, L.P. | Apparatus and methods for sending or receiving electromagnetic signals |
US9847566B2 (en) | 2015-07-14 | 2017-12-19 | At&T Intellectual Property I, L.P. | Method and apparatus for adjusting a field of a signal to mitigate interference |
US9722318B2 (en) | 2015-07-14 | 2017-08-01 | At&T Intellectual Property I, L.P. | Method and apparatus for coupling an antenna to a device |
US10033107B2 (en) | 2015-07-14 | 2018-07-24 | At&T Intellectual Property I, L.P. | Method and apparatus for coupling an antenna to a device |
US9853342B2 (en) | 2015-07-14 | 2017-12-26 | At&T Intellectual Property I, L.P. | Dielectric transmission medium connector and methods for use therewith |
US10148016B2 (en) | 2015-07-14 | 2018-12-04 | At&T Intellectual Property I, L.P. | Apparatus and methods for communicating utilizing an antenna array |
US10341142B2 (en) | 2015-07-14 | 2019-07-02 | At&T Intellectual Property I, L.P. | Apparatus and methods for generating non-interfering electromagnetic waves on an uninsulated conductor |
US10044409B2 (en) | 2015-07-14 | 2018-08-07 | At&T Intellectual Property I, L.P. | Transmission medium and methods for use therewith |
US10320586B2 (en) | 2015-07-14 | 2019-06-11 | At&T Intellectual Property I, L.P. | Apparatus and methods for generating non-interfering electromagnetic waves on an insulated transmission medium |
US9882257B2 (en) | 2015-07-14 | 2018-01-30 | At&T Intellectual Property I, L.P. | Method and apparatus for launching a wave mode that mitigates interference |
US10205655B2 (en) | 2015-07-14 | 2019-02-12 | At&T Intellectual Property I, L.P. | Apparatus and methods for communicating utilizing an antenna array and multiple communication paths |
US9628116B2 (en) | 2015-07-14 | 2017-04-18 | At&T Intellectual Property I, L.P. | Apparatus and methods for transmitting wireless signals |
US9793951B2 (en) | 2015-07-15 | 2017-10-17 | At&T Intellectual Property I, L.P. | Method and apparatus for launching a wave mode that mitigates interference |
US10090606B2 (en) | 2015-07-15 | 2018-10-02 | At&T Intellectual Property I, L.P. | Antenna system with dielectric array and methods for use therewith |
US9608740B2 (en) | 2015-07-15 | 2017-03-28 | At&T Intellectual Property I, L.P. | Method and apparatus for launching a wave mode that mitigates interference |
US9948333B2 (en) | 2015-07-23 | 2018-04-17 | At&T Intellectual Property I, L.P. | Method and apparatus for wireless communications to mitigate interference |
US9871283B2 (en) | 2015-07-23 | 2018-01-16 | At&T Intellectual Property I, Lp | Transmission medium having a dielectric core comprised of plural members connected by a ball and socket configuration |
US9912027B2 (en) | 2015-07-23 | 2018-03-06 | At&T Intellectual Property I, L.P. | Method and apparatus for exchanging communication signals |
US9749053B2 (en) | 2015-07-23 | 2017-08-29 | At&T Intellectual Property I, L.P. | Node device, repeater and methods for use therewith |
US9967173B2 (en) | 2015-07-31 | 2018-05-08 | At&T Intellectual Property I, L.P. | Method and apparatus for authentication and identity management of communicating devices |
US9735833B2 (en) | 2015-07-31 | 2017-08-15 | At&T Intellectual Property I, L.P. | Method and apparatus for communications management in a neighborhood network |
US9904535B2 (en) | 2015-09-14 | 2018-02-27 | At&T Intellectual Property I, L.P. | Method and apparatus for distributing software |
US10009063B2 (en) | 2015-09-16 | 2018-06-26 | At&T Intellectual Property I, L.P. | Method and apparatus for use with a radio distributed antenna system having an out-of-band reference signal |
US10079661B2 (en) | 2015-09-16 | 2018-09-18 | At&T Intellectual Property I, L.P. | Method and apparatus for use with a radio distributed antenna system having a clock reference |
US10136434B2 (en) | 2015-09-16 | 2018-11-20 | At&T Intellectual Property I, L.P. | Method and apparatus for use with a radio distributed antenna system having an ultra-wideband control channel |
US9769128B2 (en) | 2015-09-28 | 2017-09-19 | At&T Intellectual Property I, L.P. | Method and apparatus for encryption of communications over a network |
US9729197B2 (en) | 2015-10-01 | 2017-08-08 | At&T Intellectual Property I, L.P. | Method and apparatus for communicating network management traffic over a network |
US9876264B2 (en) | 2015-10-02 | 2018-01-23 | At&T Intellectual Property I, Lp | Communication system, guided wave switch and methods for use therewith |
US10355367B2 (en) | 2015-10-16 | 2019-07-16 | At&T Intellectual Property I, L.P. | Antenna structure for exchanging wireless signals |
US10665942B2 (en) | 2015-10-16 | 2020-05-26 | At&T Intellectual Property I, L.P. | Method and apparatus for adjusting wireless communications |
US9912419B1 (en) | 2016-08-24 | 2018-03-06 | At&T Intellectual Property I, L.P. | Method and apparatus for managing a fault in a distributed antenna system |
US9860075B1 (en) | 2016-08-26 | 2018-01-02 | At&T Intellectual Property I, L.P. | Method and communication node for broadband distribution |
US10291311B2 (en) | 2016-09-09 | 2019-05-14 | At&T Intellectual Property I, L.P. | Method and apparatus for mitigating a fault in a distributed antenna system |
US11032819B2 (en) | 2016-09-15 | 2021-06-08 | At&T Intellectual Property I, L.P. | Method and apparatus for use with a radio distributed antenna system having a control channel reference signal |
US10135146B2 (en) | 2016-10-18 | 2018-11-20 | At&T Intellectual Property I, L.P. | Apparatus and methods for launching guided waves via circuits |
US10135147B2 (en) | 2016-10-18 | 2018-11-20 | At&T Intellectual Property I, L.P. | Apparatus and methods for launching guided waves via an antenna |
US10340600B2 (en) | 2016-10-18 | 2019-07-02 | At&T Intellectual Property I, L.P. | Apparatus and methods for launching guided waves via plural waveguide systems |
US9876605B1 (en) | 2016-10-21 | 2018-01-23 | At&T Intellectual Property I, L.P. | Launcher and coupling system to support desired guided wave mode |
US10811767B2 (en) | 2016-10-21 | 2020-10-20 | At&T Intellectual Property I, L.P. | System and dielectric antenna with convex dielectric radome |
US9991580B2 (en) | 2016-10-21 | 2018-06-05 | At&T Intellectual Property I, L.P. | Launcher and coupling system for guided wave mode cancellation |
US10374316B2 (en) | 2016-10-21 | 2019-08-06 | At&T Intellectual Property I, L.P. | System and dielectric antenna with non-uniform dielectric |
US10312567B2 (en) | 2016-10-26 | 2019-06-04 | At&T Intellectual Property I, L.P. | Launcher with planar strip antenna and methods for use therewith |
US10224634B2 (en) | 2016-11-03 | 2019-03-05 | At&T Intellectual Property I, L.P. | Methods and apparatus for adjusting an operational characteristic of an antenna |
US10498044B2 (en) | 2016-11-03 | 2019-12-03 | At&T Intellectual Property I, L.P. | Apparatus for configuring a surface of an antenna |
US10225025B2 (en) | 2016-11-03 | 2019-03-05 | At&T Intellectual Property I, L.P. | Method and apparatus for detecting a fault in a communication system |
US10291334B2 (en) | 2016-11-03 | 2019-05-14 | At&T Intellectual Property I, L.P. | System for detecting a fault in a communication system |
US10340603B2 (en) | 2016-11-23 | 2019-07-02 | At&T Intellectual Property I, L.P. | Antenna system having shielded structural configurations for assembly |
US10535928B2 (en) | 2016-11-23 | 2020-01-14 | At&T Intellectual Property I, L.P. | Antenna system and methods for use therewith |
US10090594B2 (en) | 2016-11-23 | 2018-10-02 | At&T Intellectual Property I, L.P. | Antenna system having structural configurations for assembly |
US10340601B2 (en) | 2016-11-23 | 2019-07-02 | At&T Intellectual Property I, L.P. | Multi-antenna system and methods for use therewith |
US10178445B2 (en) | 2016-11-23 | 2019-01-08 | At&T Intellectual Property I, L.P. | Methods, devices, and systems for load balancing between a plurality of waveguides |
US10361489B2 (en) | 2016-12-01 | 2019-07-23 | At&T Intellectual Property I, L.P. | Dielectric dish antenna system and methods for use therewith |
US10305190B2 (en) | 2016-12-01 | 2019-05-28 | At&T Intellectual Property I, L.P. | Reflecting dielectric antenna system and methods for use therewith |
US10382976B2 (en) | 2016-12-06 | 2019-08-13 | At&T Intellectual Property I, L.P. | Method and apparatus for managing wireless communications based on communication paths and network device positions |
US10727599B2 (en) | 2016-12-06 | 2020-07-28 | At&T Intellectual Property I, L.P. | Launcher with slot antenna and methods for use therewith |
US10637149B2 (en) | 2016-12-06 | 2020-04-28 | At&T Intellectual Property I, L.P. | Injection molded dielectric antenna and methods for use therewith |
US10819035B2 (en) | 2016-12-06 | 2020-10-27 | At&T Intellectual Property I, L.P. | Launcher with helical antenna and methods for use therewith |
US10326494B2 (en) | 2016-12-06 | 2019-06-18 | At&T Intellectual Property I, L.P. | Apparatus for measurement de-embedding and methods for use therewith |
US10020844B2 (en) | 2016-12-06 | 2018-07-10 | T&T Intellectual Property I, L.P. | Method and apparatus for broadcast communication via guided waves |
US10755542B2 (en) | 2016-12-06 | 2020-08-25 | At&T Intellectual Property I, L.P. | Method and apparatus for surveillance via guided wave communication |
US10694379B2 (en) | 2016-12-06 | 2020-06-23 | At&T Intellectual Property I, L.P. | Waveguide system with device-based authentication and methods for use therewith |
US10135145B2 (en) | 2016-12-06 | 2018-11-20 | At&T Intellectual Property I, L.P. | Apparatus and methods for generating an electromagnetic wave along a transmission medium |
US9927517B1 (en) | 2016-12-06 | 2018-03-27 | At&T Intellectual Property I, L.P. | Apparatus and methods for sensing rainfall |
US10439675B2 (en) | 2016-12-06 | 2019-10-08 | At&T Intellectual Property I, L.P. | Method and apparatus for repeating guided wave communication signals |
US10168695B2 (en) | 2016-12-07 | 2019-01-01 | At&T Intellectual Property I, L.P. | Method and apparatus for controlling an unmanned aircraft |
US10139820B2 (en) | 2016-12-07 | 2018-11-27 | At&T Intellectual Property I, L.P. | Method and apparatus for deploying equipment of a communication system |
US9893795B1 (en) | 2016-12-07 | 2018-02-13 | At&T Intellectual Property I, Lp | Method and repeater for broadband distribution |
US10446936B2 (en) | 2016-12-07 | 2019-10-15 | At&T Intellectual Property I, L.P. | Multi-feed dielectric antenna system and methods for use therewith |
US10359749B2 (en) | 2016-12-07 | 2019-07-23 | At&T Intellectual Property I, L.P. | Method and apparatus for utilities management via guided wave communication |
US10027397B2 (en) | 2016-12-07 | 2018-07-17 | At&T Intellectual Property I, L.P. | Distributed antenna system and methods for use therewith |
US10389029B2 (en) | 2016-12-07 | 2019-08-20 | At&T Intellectual Property I, L.P. | Multi-feed dielectric antenna system with core selection and methods for use therewith |
US10243270B2 (en) | 2016-12-07 | 2019-03-26 | At&T Intellectual Property I, L.P. | Beam adaptive multi-feed dielectric antenna system and methods for use therewith |
US10547348B2 (en) | 2016-12-07 | 2020-01-28 | At&T Intellectual Property I, L.P. | Method and apparatus for switching transmission mediums in a communication system |
US10411356B2 (en) | 2016-12-08 | 2019-09-10 | At&T Intellectual Property I, L.P. | Apparatus and methods for selectively targeting communication devices with an antenna array |
US10601494B2 (en) | 2016-12-08 | 2020-03-24 | At&T Intellectual Property I, L.P. | Dual-band communication device and method for use therewith |
US9998870B1 (en) | 2016-12-08 | 2018-06-12 | At&T Intellectual Property I, L.P. | Method and apparatus for proximity sensing |
US10389037B2 (en) | 2016-12-08 | 2019-08-20 | At&T Intellectual Property I, L.P. | Apparatus and methods for selecting sections of an antenna array and use therewith |
US10777873B2 (en) | 2016-12-08 | 2020-09-15 | At&T Intellectual Property I, L.P. | Method and apparatus for mounting network devices |
US10326689B2 (en) | 2016-12-08 | 2019-06-18 | At&T Intellectual Property I, L.P. | Method and system for providing alternative communication paths |
US9911020B1 (en) | 2016-12-08 | 2018-03-06 | At&T Intellectual Property I, L.P. | Method and apparatus for tracking via a radio frequency identification device |
US10103422B2 (en) | 2016-12-08 | 2018-10-16 | At&T Intellectual Property I, L.P. | Method and apparatus for mounting network devices |
US10916969B2 (en) | 2016-12-08 | 2021-02-09 | At&T Intellectual Property I, L.P. | Method and apparatus for providing power using an inductive coupling |
US10069535B2 (en) | 2016-12-08 | 2018-09-04 | At&T Intellectual Property I, L.P. | Apparatus and methods for launching electromagnetic waves having a certain electric field structure |
US10938108B2 (en) | 2016-12-08 | 2021-03-02 | At&T Intellectual Property I, L.P. | Frequency selective multi-feed dielectric antenna system and methods for use therewith |
US10530505B2 (en) | 2016-12-08 | 2020-01-07 | At&T Intellectual Property I, L.P. | Apparatus and methods for launching electromagnetic waves along a transmission medium |
US10264586B2 (en) | 2016-12-09 | 2019-04-16 | At&T Mobility Ii Llc | Cloud-based packet controller and methods for use therewith |
US9838896B1 (en) | 2016-12-09 | 2017-12-05 | At&T Intellectual Property I, L.P. | Method and apparatus for assessing network coverage |
US10340983B2 (en) | 2016-12-09 | 2019-07-02 | At&T Intellectual Property I, L.P. | Method and apparatus for surveying remote sites via guided wave communications |
CN106707250B (en) * | 2017-01-24 | 2019-05-21 | 西安电子科技大学 | Radar array Adaptive beamformer method based on mutual coupling calibration |
US9973940B1 (en) | 2017-02-27 | 2018-05-15 | At&T Intellectual Property I, L.P. | Apparatus and methods for dynamic impedance matching of a guided wave launcher |
US10298293B2 (en) | 2017-03-13 | 2019-05-21 | At&T Intellectual Property I, L.P. | Apparatus of communication utilizing wireless network devices |
GB2564397B (en) * | 2017-07-06 | 2021-12-08 | Airspan Ip Holdco Llc | Scanning in a wireless network |
TWI661611B (en) | 2017-09-29 | 2019-06-01 | Arcadyan Technology Corporation | Smart antenna and controlling method thereof for passive wi-fi device |
KR102413508B1 (en) * | 2018-02-15 | 2022-06-24 | 텔레폰악티에볼라겟엘엠에릭슨(펍) | Signal strength scaling of an uplink measurement signal and a corresponding uplink transmission beam according to the estimated interference level |
KR102526543B1 (en) | 2018-09-10 | 2023-04-28 | 삼성전자주식회사 | An electronic device comprising an antenna module |
KR101958163B1 (en) * | 2019-01-02 | 2019-07-04 | 알에프코어 주식회사 | Beamformer including signal detector for compensating weights, wireless transmitting and receiving device including beamformer, and operating method of wireless transmitting and receiving device |
CN110504544B (en) * | 2019-07-31 | 2021-11-23 | 奇酷互联网络科技(深圳)有限公司 | Antenna angle adjusting method, signal transmitter and storage medium |
Family Cites Families (46)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3560978A (en) * | 1968-11-01 | 1971-02-02 | Itt | Electronically controlled antenna system |
US3725938A (en) * | 1970-10-05 | 1973-04-03 | Sperry Rand Corp | Direction finder system |
US3766559A (en) * | 1971-10-20 | 1973-10-16 | Harris Intertype Corp | Adaptive processor for an rf antenna |
FR2196527B1 (en) * | 1972-08-16 | 1977-01-14 | Materiel Telephonique | |
US3950753A (en) * | 1973-12-13 | 1976-04-13 | Chisholm John P | Stepped cardioid bearing system |
US3999182A (en) * | 1975-02-06 | 1976-12-21 | The Bendix Corporation | Phased array antenna with coarse/fine electronic scanning for ultra-low beam granularity |
US4170766A (en) * | 1978-01-27 | 1979-10-09 | Raytheon Company | Beamformer |
DE2812575C2 (en) | 1978-03-22 | 1983-01-27 | Siemens AG, 1000 Berlin und 8000 München | Phased antenna field |
US4387378A (en) * | 1978-06-28 | 1983-06-07 | Harris Corporation | Antenna having electrically positionable phase center |
US4260994A (en) * | 1978-11-09 | 1981-04-07 | International Telephone And Telegraph Corporation | Antenna pattern synthesis and shaping |
US4236158A (en) * | 1979-03-22 | 1980-11-25 | Motorola, Inc. | Steepest descent controller for an adaptive antenna array |
US4488155A (en) * | 1982-07-30 | 1984-12-11 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Method and apparatus for self-calibration and phasing of array antenna |
JPS5950603A (en) | 1982-09-17 | 1984-03-23 | Nec Corp | Transmission signal system |
US4516126A (en) * | 1982-09-30 | 1985-05-07 | Hazeltine Corporation | Adaptive array having an auxiliary channel notched pattern in the steered beam direction |
US4631546A (en) * | 1983-04-11 | 1986-12-23 | Rockwell International Corporation | Electronically rotated antenna apparatus |
CA1239223A (en) * | 1984-07-02 | 1988-07-12 | Robert Milne | Adaptive array antenna |
EP0188504B1 (en) * | 1984-07-23 | 1989-12-13 | The Commonwealth Of Australia | Adaptive antenna array |
US5510796A (en) * | 1984-12-31 | 1996-04-23 | Martin Marietta Corporation | Apparatus for wind shear compensation in an MTI radar system |
US4872016A (en) * | 1988-09-06 | 1989-10-03 | Grumman Aerospace Corporation | Data processing system for a phased array antenna |
FR2663469B1 (en) * | 1990-06-19 | 1992-09-11 | Thomson Csf | DEVICE FOR SUPPLYING RADIANT ELEMENTS TO A NETWORK ANTENNA, AND ITS APPLICATION TO AN ANTENNA OF AN MLS TYPE LANDING AID SYSTEM. |
FR2666178A1 (en) * | 1990-08-21 | 1992-02-28 | Etudes Realis Protect Electron | HIGH FREQUENCY EMITTING OR RECEIVING ANTENNA DEVICE. |
US5038146A (en) * | 1990-08-22 | 1991-08-06 | Raytheon Company | Array built in test |
US5117236A (en) * | 1990-10-19 | 1992-05-26 | Motorola, Inc. | Antenna pattern selection for optimized communications |
IL100213A (en) * | 1990-12-07 | 1995-03-30 | Qualcomm Inc | CDMA microcellular telephone system and distributed antenna system therefor |
US5303240A (en) * | 1991-07-08 | 1994-04-12 | Motorola, Inc. | Telecommunications system using directional antennas |
CA2071714A1 (en) * | 1991-07-15 | 1993-01-16 | Gary George Sanford | Electronically reconfigurable antenna |
JP2684888B2 (en) * | 1991-08-06 | 1997-12-03 | 国際電信電話株式会社 | Adaptive array antenna control method |
US5634199A (en) * | 1993-04-14 | 1997-05-27 | Stanford University | Method of subspace beamforming using adaptive transmitting antennas with feedback |
EP0954050A1 (en) * | 1993-05-27 | 1999-11-03 | Griffith University | Antennas for use in portable communications devices |
US5437055A (en) * | 1993-06-03 | 1995-07-25 | Qualcomm Incorporated | Antenna system for multipath diversity in an indoor microcellular communication system |
US5502447A (en) * | 1993-10-28 | 1996-03-26 | Hazeltine Corporation | Beam sharpened pencil beam antenna systems |
US5592178A (en) * | 1994-06-01 | 1997-01-07 | Raytheon Company | Wideband interference suppressor in a phased array radar |
JP3305877B2 (en) * | 1994-06-23 | 2002-07-24 | 株式会社東芝 | Spread spectrum wireless communication system and wireless communication device used in this system |
US5621752A (en) * | 1994-06-23 | 1997-04-15 | Qualcomm Incorporated | Adaptive sectorization in a spread spectrum communication system |
US5617102A (en) * | 1994-11-18 | 1997-04-01 | At&T Global Information Solutions Company | Communications transceiver using an adaptive directional antenna |
US5680142A (en) * | 1995-11-07 | 1997-10-21 | Smith; David Anthony | Communication system and method utilizing an antenna having adaptive characteristics |
US5739784A (en) * | 1995-11-20 | 1998-04-14 | Motorola, Inc. | Method and beam stepping apparatus for a satellite cellular communication system |
US6038272A (en) * | 1996-09-06 | 2000-03-14 | Lucent Technologies Inc. | Joint timing, frequency and weight acquisition for an adaptive array |
US5767807A (en) * | 1996-06-05 | 1998-06-16 | International Business Machines Corporation | Communication system and methods utilizing a reactively controlled directive array |
US5905473A (en) * | 1997-03-31 | 1999-05-18 | Resound Corporation | Adjustable array antenna |
US6037905A (en) * | 1998-08-06 | 2000-03-14 | The United States Of America As Represented By The Secretary Of The Army | Azimuth steerable antenna |
US6125137A (en) * | 1998-09-11 | 2000-09-26 | Motorola, Inc. | Apparatus and method for performing a signal search in a coherent wireless communication system |
US6792290B2 (en) * | 1998-09-21 | 2004-09-14 | Ipr Licensing, Inc. | Method and apparatus for performing directional re-scan of an adaptive antenna |
US6100843A (en) * | 1998-09-21 | 2000-08-08 | Tantivy Communications Inc. | Adaptive antenna for use in same frequency networks |
US6473036B2 (en) * | 1998-09-21 | 2002-10-29 | Tantivy Communications, Inc. | Method and apparatus for adapting antenna array to reduce adaptation time while increasing array performance |
US6115409A (en) * | 1999-06-21 | 2000-09-05 | Envoy Networks, Inc. | Integrated adaptive spatial-temporal system for controlling narrowband and wideband sources of interferences in spread spectrum CDMA receivers |
-
2002
- 2002-10-28 US US10/282,928 patent/US6933887B2/en not_active Expired - Lifetime
-
2003
- 2003-10-24 TW TW092129544A patent/TW200509458A/en unknown
- 2003-10-28 JP JP2004548540A patent/JP2006504354A/en active Pending
- 2003-10-28 WO PCT/US2003/034215 patent/WO2004040692A1/en not_active Application Discontinuation
- 2003-10-28 CA CA002503042A patent/CA2503042C/en not_active Expired - Fee Related
- 2003-10-28 EP EP03779376A patent/EP1559169A4/en not_active Ceased
- 2003-10-28 MX MXPA05004603A patent/MXPA05004603A/en active IP Right Grant
- 2003-10-28 AU AU2003285061A patent/AU2003285061A1/en not_active Abandoned
- 2003-10-28 KR KR1020057007192A patent/KR100817620B1/en not_active IP Right Cessation
- 2003-10-28 CN CNA2003801020939A patent/CN1708876A/en active Pending
-
2004
- 2004-08-10 US US10/914,982 patent/US7009559B2/en not_active Expired - Fee Related
-
2005
- 2005-05-27 NO NO20052572A patent/NO20052572L/en not_active Application Discontinuation
Also Published As
Publication number | Publication date |
---|---|
CN1708876A (en) | 2005-12-14 |
TW200509458A (en) | 2005-03-01 |
KR100817620B1 (en) | 2008-03-31 |
EP1559169A4 (en) | 2006-06-07 |
CA2503042A1 (en) | 2004-05-13 |
EP1559169A1 (en) | 2005-08-03 |
JP2006504354A (en) | 2006-02-02 |
AU2003285061A1 (en) | 2004-05-25 |
US6933887B2 (en) | 2005-08-23 |
MXPA05004603A (en) | 2005-10-26 |
KR20050073587A (en) | 2005-07-14 |
NO20052572D0 (en) | 2005-05-27 |
NO20052572L (en) | 2005-07-28 |
US7009559B2 (en) | 2006-03-07 |
WO2004040692A1 (en) | 2004-05-13 |
US20030222818A1 (en) | 2003-12-04 |
US20050068231A1 (en) | 2005-03-31 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CA2503042C (en) | Method and apparatus for adapting antenna array using received predetermined signal | |
US6473036B2 (en) | Method and apparatus for adapting antenna array to reduce adaptation time while increasing array performance | |
US6404386B1 (en) | Adaptive antenna for use in same frequency networks | |
US6518920B2 (en) | Adaptive antenna for use in same frequency networks | |
US6400317B2 (en) | Method and apparatus for antenna control in a communications network | |
US7289827B2 (en) | Method and apparatus for performing directional re-scan of an adaptive antenna | |
US6600456B2 (en) | Adaptive antenna for use in wireless communication systems | |
KR100883943B1 (en) | Wireless communications with an adaptive antenna array | |
US7215297B2 (en) | Adaptive antenna for use in wireless communication systems | |
US20040053634A1 (en) | Adaptive pointing for use with directional antennas operating in wireless networks | |
KR20060130770A (en) | Mitigation of wireless transmit/receive unit (wtru) to wtru interference using multiple antennas or beams | |
WO2005046080A1 (en) | Method and apparatus for multi-beam antenna system | |
Basit | Smart Antenna in 3G Networks |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
MKLA | Lapsed |
Effective date: 20181029 |