WO2002032028A1

WO2002032028A1 - Microcell delay-sectorization system for cdma base transmitter site

Info

Publication number: WO2002032028A1
Application number: PCT/US2001/031788
Authority: WO
Inventors: Matthew Fuerter
Original assignee: Repeater Technologies
Priority date: 2000-10-13
Filing date: 2001-10-09
Publication date: 2002-04-18
Also published as: AU2002211636A1

Abstract

A cellular telephone microcell system embodiment of the present invention combines a single microcell base station with a delay-sectorization circuitry (66), to modify a single sectored or omnidirectional microcell into a multiple-sector microcell. The delay-sectorization circuitry (66) provides the interconnection, filtering, and amplification requirements for conversion of a single sectored/omni-directional microcell into a three-sector microcell (64a, 64b, 64c). Both the initial primary sector and one or more secondary sectors are connected to two antennas. Each of the sector preferably acts simultaneously, as both a receiver and transmitter antenna depending on the number of CDMA channels used in the application. Receive diversity is supported within each of the sectors, the standard dual branch diversity of the microcell, and between each of the sectors, via strategic use of delay elements within the delay-sectorization circuitry (66). Transmit delay diversity is also preferably provided between each of the sectors.

Description

MICROCELL DELAY-SECTORIZATION SYSTEM FOR CDMA BASE TRANSMITTER SITE

FIELD OF THE INVENTION

The invention relates to the field of cellular telephone systems. More particularly, the invention relates to the use of delay combining circuitry to enhance the performance and economy of a sectorized microcell base transmitter site.

BACKGROUND OF THE INVENTION

Code division multiple access (CDMA) techniques are commonly used in communication systems, to allow communications between a large number of system users. Personal communication system (PCS) cellular telephone services typically use code division multiple access (CDMA) modulation of radio carriers operating at 1900 MHz, but is not limited to 1900 MHz.

While the use of microwave signals and modulation offers many benefits, multi- path interference can occur when a signal that proceeds directly from a transmitter to a receiver is interfered with by a reflected signal that takes a longer path and arrives at the receiver late enough to confuse the demodulation. Such reflected multi-path signals can wane and ebb, and the delays can change as a mobile receiver moves about. Occasionally, the amplitude of the reflected signals can exceed the directly received signal strength.

Figure 1 is a partial schematic diagram of a cellular communications system 10. A cellular system 10 is typically comprised of several base transmitter sites (BTS) 16, wherein each base transmitter site 16 is typically comprised of one or more interconnected microcells 20, which are each directed to provide forward-link transmission and reverse-link reception of signals 12 from a regional portion (i.e. a sector) 24 (e.g. such as sector 24a) of a service region 22 surrounding the base transmitter site 16. One or more remote users RU, having remote transceivers (i.e. cell phones) CP, may be located within the service region 22, and may send or receive signals 12 between the remote transceivers CP and the base transmitter site 16. One challenge for reliable yet economic mobile telephone service is keeping the size of each service region (i.e. cell) 22 served by a base transmitter site 16 small enough to provide strong signal levels everywhere of importance in the cell 22, while at the same time organizing the cells 22 to be large enough such that base transmitter sites 16 are economically distributed to cover an extended cellular service region.

Each of the microcells 20 within a conventional base transmitter site 16 typically includes two antennas 14a, 14b and associated base transmitter site componentry, and operates as an individual base station, to provide forward and reverse link service for a sector (e.g. 24a) for the base transmitter site 16. Therefore, the cost of a conventional microcell 20 within a three-microcell base transmitter site 16 (e.g. such as wherein each microcell provides service to a 120 degree sector 24) is approximately one third of the cost of a conventional base transmitter site 16. Each of the conventional microcells 20 are then linked, through common base transmitter site componentry, such as to a public switched telephone network PSTN.

The antennas 14a, 14b used within a microcell 20 are connected through antenna ports 18, and are usually either directional, or omni-directional antennas 14, whereby the microcell 20 provides forward-link transmission of signals 15 to one or more remote users RU within the microcell sector 24 (e.g. sector 24a), and whereby the microcell 20 provides reception of reverse-link signals 12 from one or more remote users RU within the microcell sector 24.

Omni-directional antennas 14, which commonly have a relatively small gain, are typically used to service a short-distance/large angular regions 24. Directional antennas 14 provide a higher gain than omni-directional antennas 14, since the power for a directional antenna 14 is focused within a smaller angular region 24.

For example, directional antennas 14 are typically directed to cover 120 degree sectors 24, while an omnidirectional antenna may cover a full 360 degree region 22.

As seen in Figure 1 , one or more full-duplex radio-signal repeaters 26 may be used in communication with microcells 20 at a base transmitter site 16. Relatively inexpensive full-duplex radio-signal repeaters 26, such as over-the-air (OA) 800C network CDMA channelized repeaters, available through Repeater Technologies Inc., of Sunnyvale, CA, are commonly used to extend 28 the service area 22 of a relatively expensive base transmitter site 16. The CDMA channelized repeaters 26 are typically placed at the fringes of a cell area 22, and expand the cell coverage 28 of the base transmitter site 16 around the CDMA channelized repeater 16, such as shown by extended regions 28 for sectors 24b and 24c shown in Figure 1.

Figure 2 shows a plurality of base transmitter sites 16 located within a cellular service region 30. Base transmitter sites 16 which are located in rural regions are often preferably located to serve corridors, such as along a highway HWY. One or more remote users RU may be located within a coverage area 22 for a base transmitter site 16 at any given time, and typically move between sectors

24a,24b,24c within a cell 22, and between cells 22. The selected locations of base transmitter sites 16 are also often defined by surrounding terrain TE.

Several repeaters 26 are also often preferably deployed along long stretches of interstate freeways or highways HWY, as shown in Figure 1 , such that a single base transmitter site 16 can serve as much as sixty-one miles of highway HWY, where two similar base transmitter sites 16 without the use of repeaters 26 may be required to service a fifty-four mile stretch of highway HWY.

If competing CDMA transmission signals 12 arrive more than one chip apart from each other at a repeater 26 or at a microcell 20, an ordinary CDMA receiver can easily resolve them. However, if multipath signal reflections cause the CDMA transmission signals 12 to arrive less than one chip apart from each other, a diversity receiver is needed. A so-called RAKE-receiver is used, for example, with two spatially separated receive antennas to receive a CDMA transmission and its delayed copy from a transmitter. A CDMA channelized repeater 26 that includes receive-diversity operation is the over-the-air 1900C Network Repeater 26, by Repeater Technologies Inc., of Sunnyvale, CA.

K. Gilhousen, R. Padovani, and C. Wheatley, Method and System for Providing a Soft Handoffin Communications in a CDMA Cellular Telephone System, U.S. Patent No. 5,101 ,501 (31 March 1992) disclose a system for directing communications signals between a mobile user and cell sites, as the mobile user moves between cell site service areas. RAKE-receϊvers use many correlators that are fed the multipath signals 12. After despreading by correlators, such signals are combined, such as by maximal ratio combining. Since the received multipath signals fade independently, diversity order and thus performance are improved. After spreading and modulation, the signal 12 is transmitted and it passes through a multipath channel, which can be modeled by a tapped delay line (i.e., the reflected signals are delayed and attenuated in the channel). A receiver finger is included in a RAKE-receiver for each multipath component. The received signals are correlated by a spreading code that is time-aligned with a multipath signal delay. After despreading, the signals are weighted and combined. A. Schneider, CDMA System Having

Time-Distributed Transmission Paths for Multi-Path Reception, U. S. Patent 5,781 ,541 (14 July 1998) discloses RAKE-receiver componentry, operations and applications.

As seen in Figure 1 and Figure 2, in addition to the use of repeaters 26, three microcells 20, each having different directional antenna pairs 14a, 14b are commonly located on a single mast, wherein the antenna pairs 14a, 14b are pointed 120-degrees apart at a base transmitter site 16 in a cellular phone microcell 22, to cover a full 360-degrees of azimuth. Figure 3 is a perspective view 32 of a base transmitter site 16 having a plurality of adjustable sectorized microcells 20a,20b,20c. Each of the adjustable sectorized microcells 20a,20b,20c preferably includes sector direction adjustment 34, to direct each of the microcells 20a,20b,20c toward a desired sector 24a,24b,24c, and preferably includes sector tilt adjustment 36, such as to substantially conform each of the microcells 20a,20b,20c to the surrounding terrain TE.

Microcells with Three-Way Splitters. Figure 4 is a schematic diagram 40 of a base transmitter site 16 having three-way splitters 42 between antenna sectors 24a, 24b, 24c. A microcell 20 can be configured to cover 360 degrees of azimuth, by adding three-way splitters 42 to each of the microcell signal paths

44a,44b, and by distributing the RF to the directional antenna pairs 14a, 14b for each of the sectors 24a,24b,24c. While this configuration provides individual "sectors" 24a,24b,24c, which can be directed and tilted individually, the use of three-way splitters 42 results in a degradation of approximately 5 db for both the noise figure and the forward power of the microcell 20. Another common problem which may result from the use of a three-way splitter 42 is interference fringing, which occurs between coherent forward-link signals 15 that are launched by their respective T_x/R_x antennas 14b located in neighboring sectors 24a, 24b, 24c. Interference fringing results from constructive and destructive interference between the forward-link signals 15 transmitted from neighboring antennas 14b, and nulls in the regions 48 located between sectors 24a,24b,24c can be generated.

Microcell Having Bi-Directional Amplifiers. Two bi-directional amplifiers and the hardware to combine them can be used to improve performance for a three- way splitter base transmitter configuration 40. The use of bi-directional amplifiers makes up for combinational losses, and improves noise figures, while increasing overall forward power.

However bi-directional amplifiers are typically band-selective, rather than channel selective, and don't effectively repeat the channels used in a microcell 20. Microcells 20 having bi-directional amplifiers are preferably adjustable, to independently set the azimuths and tilt on each sector 24. Lower noise figure and higher power output is achieved, as compared to a basic "three way splitter" system 40. The noise figure is roughly 25 dB above the microcell noise figure, assuming low noise amplifiers (LNAs) having two dB noise figure are used in the bi-directional amplifiers.

A microcell 20 combined with two bi-directional amplifiers may provide an improved noise figure and increased forward power, to increase the coverage range for the microcell 20 by approximately eighty-five percent over an omni microcell or a basic "three way splitter" base transmitter site configuration 40. However, such a configuration still lacks passively soft hand-off of signals between each of the sectors 24a,24b,24c, reducing system capacity, and resulting in fringing in the sector overlap regions 48, due to coherent addition of the individual signals 15 from the separate sector forward-link antennas 14b.

Furthermore, bi-directional amplifiers are generally not channel selective, which increases the probability of interference between the microcell 20 and other mobile and fixed wireless services. Such a system requires bi-directional amplifiers configured such that there are four reverse link amplification paths and two forward link amplification paths. Two bi-directional amplifiers and two low noise amplifiers are typically used to provide these amplification paths. The gains must be well balanced on all of the reverse paths, to maintain adequate reverse link diversity performance.

A RAKE-receiver can be used to better tolerate multipath interference by using spatial diversity. F. Adachi, et al., Receiver and Repeater for Spread Spectrum Communications, U. S. Patent 5,652,765 (29 July 1997) disclose the use of a repeater in RAKE-reception, wherein circulators are used to separate received and transmitted signals for amplifiers. However, circulators are typically costly, and inject large signal losses that must be overcome. Circuits are used to inject the chip-delays used by the RAKE-receivers. Since the repeaters are remote from the base station, within the service zone, separate installation sites and power sources are typically needed.

While conventional splitter and bi-directional amplifier techniques may be used to used to expand the capacity of a microcell, while allowing azimuth and tilt adjustment between sectors, they fail to provide a system which provides passive soft hand-off between sectors, while providing channel selectivity, and while reducing pattern interference fringing between sectors. The development of such a microcell system would constitute a major technological advance.

SUMMARY OF THE INVENTION

A cellular telephone microcell system embodiment of the present invention combines a single microcell base station with a delay-sectorization circuitry, to modify a single sectored or omnidirectional microcell into a multiple-sector microcell. The delay-sectorization circuitry provides the interconnection, filtering, and amplification requirements and conversion of a single sectored/omni- directional microcell into a three-sector microcell. Both the initial primary sector and one or more secondary sectors are connected to two antennas. Each of the sector preferably acts simultaneously, as both a receiver and transmitter antenna (depending on the number of CDMA channels used in the application). Receive diversity is supported for each of the sectors, the standard dual branch diversity of the microcell, and between each of the sectors via strategic use of delay elements within the delay-sectorization circuitry. Transmit delay diversity is also preferably provided between each of the sectors. Directional couplers are used in both ports of the primary microcell, to connect the delay-sectorization circuitry to the primary microcell.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows full-duplex radio-signal repeaters in communication with microcells at a base transmitter site;

Figure 2 shows a plurality of base transmitter sites located within a cellular service region;

Figure 3 is a perspective view of a base transmitter site having a plurality of adjustable sectorized microcells;

Figure 4 is a schematic diagram of a base transmitter site having three-way splitters between antenna sectors;

Figure 5 is a basic schematic diagram of a base transmitter site having directional coupling to primary signal paths, same time of reverse-link arrival on different paths in-between secondary sectors, and different time-of-arrival for reverse-link paths within each secondary sector;

Figure 6 is a schematic diagram of a base transmitter site having directional coupling to primary signal paths, and reverse-path delay combine diversity between antenna sectors;

Figure 7 shows time of arrival of signals at antenna input ports for the microcell shown in Figure 8;

Figure 8 is a basic schematic diagram of a base transmitter site having directional coupling to primary signal paths, same time-of-arrival of reverse-link signals within each secondary sector, and different time-of-arrival for reverse-link paths between secondary sectors; Figure 9 is a schematic diagram of a base transmitter site having directional coupling to primary signal paths, and reverse-path delay combine diversity between antenna sectors, same time-of-arrival of reverse-link signals within each sector;

Figure 10 shows time of arrival of signals at antenna input ports for the microcell shown in Figure 9;

Figure 11 is a schematic diagram of a base transmitter site having directional coupling to primary signal paths, and forward-path time diversity between antenna sectors;

Figure 12 shows time of transmission of forward-link signals at transmission antenna ports for the microcell shown in Figure 11 ;

Figure 13 is a detailed schematic diagram of a base transmitter site having directional coupling to primary signal paths, the same time of reverse-link arrival on different paths in-between secondary sectors, and different time-of-arrival for reverse-link paths within each secondary sector;

Figure 14 is a detailed schematic diagram of a modular base transmitter site, having delay combiner modules and an interconnection module, having directional coupling to primary signal paths, same-time reverse-link arrival on different paths in-between secondary sectors, and different time-of-arrival for reverse-link paths within each secondary sector;

Figure 15 is a detailed schematic diagram of a base transmitter site having directional coupling to primary signal paths, differential reverse-link and forward- link delays between sectors, and same time-of-arrival for reverse-link paths within each secondary sector;

Figure 16 is a detailed schematic diagram of a modular base transmitter site, having delay combiner modules and an interconnection module, having directional coupling to primary signal paths, differential reverse-link and forward-link delays between sectors, and same time-of-arrival for reverse-link paths within each secondary sector; Figure 17 is a basic interconnection diagram for a modular base transmitter site, having delay combiner modules and an interconnection module interconnected to a diversity microcell;

Figure 18 is a perspective view of a modular base transmitter site, having delay combiner modules and an interconnection module interconnected to a diversity microcell;

Figure 19 shows a cloverleaf sector configuration diagram for a delay-sectorzation system, having a two sectored microcell or base transmitter site coupled with two delay combiner modules;

Figure 20 shows a three sector configuration diagram for a delay-sectorzation system, having a single microcell or base transmitter site coupled with two delay combiner modules;

Figure 21 shows a multiple sector configuration diagram for a delay-sectorization system, having a microcell or base transmitter site coupled with a plurality of delay combiner modules; and

Figure 22 is a schematic diagram of modifications to an existing diversity repeater or to provide a second delay combiner module for a delay sectorized system.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 5 is a basic schematic diagram of a delay sectorized microcell system 50a having directional coupling to primary signal paths 52a, 52b. A first sector 64a, referred herein as an alpha sector 64a, having a receive R_x antenna 14a and a transmit receive T_XR_X antenna 14b is respectively coupled, through a first signal path 52a and a second signal path 52b, to a first microcell port 58a and a second microcell port 58b of a diversity microcell 54 at a delay-sectorized base transmitter site 56. One or more secondary sectors 64b-64n (e.g. such as a beta sector 64b and a gamma sector 64c) are then coupled to the first signal path 52a and a second signal path 52b, using directional couplers 60. In some embodiments of the delay sectorized microcell system 50a, the diversity microcell 54 is similar to a conventional microcell 20. However, the CDMA diversity microcell 20 is enhanced with delay-sectorization circuitry 66, to provide decorrelated forward link signals 15 and reverse-link signals 12 between the primary sector 64a and additional sectors 64 (e.g. 64b-64n). As well, the CDMA diversity microcell 20 is preferably adjusted to search a wider time window across signal ports 58a,58b, such as to capture decorrelated reverse-link signals 12 which are delayed from each other, either between sectors 64, or within a given sector 64 (e.g. such as for sector 64b)

Directional Couplers. The directional couplers 60 provide directivity to the coupled secondary paths 68a,68b, for both forward link signals 15 (from the base station 56 to a mobile transceiver CP) and reverse link signals 12 (from a mobile transceiver CP to the base station 56). For example, in Figure 5, the first secondary path 68a and the first port 58a for the diversity microcell 54 are coupled through the directional coupler 60a, while the first secondary path 68a and the R_x antenna 14a in the alpha sector 64a are not coupled. Similarly, the second secondary path 68b and the second port 58b for the diversity microcell

54 are coupled through the directional coupler 60b, while the second secondary path 68b and the T_XR_X antenna 14b in the alpha sector 64a are not coupled.

Therefore, the directional couplers 60 connect the secondary delay combining circuits 68a,68b to respective microcell input ports 58a,58b, while preventing reverse link signals 12 from the secondary delay combining circuits 58a,58b from being re-transmitted from the alpha sector antennas 14a, 14b.

In some embodiments of the delay sectorized microcell system 50, the directional couplers are either Type 779D or Type 797D directional couplers, available through Hewlett-Packard Company, of Palo Alto, CA.

Delay elements 62 are interconnected between the receive R_x antennas 14a and the transmit receive T_XR_X antennas 14b for the beta sector 64b and a gamma sector 64c, to provide time decorrelation for reverse link signals 12 and for forward link signals 15. In some embodiments of the delay sectorization circuitry 66, the delay elements 62 are SAW filters or channel select filters. The time decorrelation provided by delay elements 62 between different signals is preferably equal to or greater than one chip, such that forward link signals 15 do not interfere with each other between neighboring sectors 64, and such that reverse link signals 12 are decorrelated appropriately at the diversity microcell

(i.e. such that each of reverse link signals 12 may be received). As shown in Figure 5, for forward-link transmission of output signals 15 from the delay sectorized microcell 50a, an output signal 15 is first transmitted from the T_XR_X antenna 14b on the alpha sector 64a. The same output signal 15 is coupled to the second secondary path 68b by the directional coupler 60b, and is then output from the T_XR_X antenna 14b on the gamma sector 64c, which is delayed by delay element 62a on the second secondary path 68b. The output signal 15 is also output from the T_XR_X antenna 14b on the beta sector 64b, which is delayed by both delay element 62a and delay element 62b on the second secondary path 68b. Therefore, the delay sectorized microcell 50a provides time delay diversity between forward link signals 15 transmitted from different sectors 64a, 64b,64c.

For reverse-link reception of input signals 12 at the delay sectorized microcell 50a, an input signal 12 typically arrives at both an R_X antenna 14a and a T_XR_X antenna 14b at one or more sectors 64a,64b,64c. The reverse-link signal 12 is a multipath signal 12, having a plurality of decorrelated reverse link signal paths 12a, 12b. The incoming reverse-link signal 12 is a fading signal, meaning that the amplitude of the reverse-link signal 12 is rapidly changing, due to propagation effects. This reverse-link signal 12 is can be received simultaneously by both antennas 14a, 14b. The instantaneous amplitude of the reverse-link signal 12 at any given point in space (in this case the space that is occupied by the CDMA microcell antenna system 20) will be different from the instantaneous amplitude at any other point in space. The instantaneous amplitude at any given point is space is also dependent on the polarization of each antenna 14 (e.g. such as antenna 14a), and the direction that each antenna 14 is pointed. This is shown in Figure 5 as a fading signal 12, consisting of a plurality of signals 12a, 12b.

The antennas 14a, 14b are typically configured such that the fading processes affecting the signals received by each antenna 14 are not correlated. That is, the signals 12 received on each individual antenna 14 (e.g. such as antenna 14a) fade independently of the signals on the other antenna 14 (e.g. such as antenna 14b). When this relationship exists between a set of signals 12, the signals 12a, 12b are said to be mutually decorrelated. The antennas 14a, 14b are therefore configured such that mutual decorrelation exists between the signals

12a, 12b. There are many different ways to configure the antennas 14a, 14b, such that the mutually decorrelated relationship exists between the signals 12a- 12n. Any configuration which achieves this relationship is acceptable.

As described above, the instantaneous amplitude of the signals 12a, 12b is a function of position, polarization, and arrival direction. Thus spatial separation, polarization separation, angular separation, or any combination of these, can be used to provide signals 12a, 12b which possess a mutually decorrelated relationship.

Two common techniques for achieving mutual decorrelation in a mobile radio environment are spatial separation and polarization separation. When spatial separation is used to provide decorrelated signals, the antennas 14a, 14b must typically be separated by 10-20 wavelengths to achieve satisfactory decorrelation. When polarization separation is used, the antennas 14 are polarized such that the polarization between the antennas 14a, 14b is orthogonal.

The required total per bit energy to noise density ratio (E_b/l₀)_Tota| is usually specified for a given level of system performance under a set of predefined conditions, which include the correlation between paths 12a, 12b, the number of paths 12a, 12b, the speed of a mobile user, and the channel conditions encountered. Almost always, the channel conditions are assumed to be a time dispersive channel, with an amplitude that is Rayleigh distributed. The speed of a mobile user MU is usually assumed to be that associated with the type of morphology the mobile user MU is operating in. The correlation between paths 12a, 12b is almost always considered to be zero (independent fading paths with a typical correlation less than 0.7). This leaves only the number of paths 12a,12n and the mobile speed as the factors which determine the total per bit energy to noise density ratio (E_b l₀)_Tota|.

As seen in Figure 5, reverse link signals 12 which are received by the R_x antenna

14a at the alpha sector 64a are transferred through the first signal path 52a to the first port 58a of the diversity microcell 54. Reverse link signals 12 which are received by the R_x antenna 14a at the beta sector 64b are also transferred, through the directional coupler 60a, to the first port 58a of the diversity microcell 54, and are delayed by a delay element 62c. Input signals 12 which are received by the R_x antenna 14a at the gamma sector 64c are also transferred, through the directional coupler 60a, to the first port 58a of the diversity microcell 54, and are delayed by both delay element 62c and delay element 62d.

Similarly, reverse link signals 12 which are received by the T_XR_X antenna 14b at the alpha sector 64a are transferred through the second signal path 52b to the second port 58b of the diversity microcell 54. Reverse link signals 12 which are received by the T_XR_X antenna 14b at the gamma sector 64c are also transferred, through the directional coupler 60b, to the second port 58b of the diversity microcell 54, and are delayed by a delay element 62a. Input signals 12 which are received by the T_XR_X antenna 14b at the beta sector 64b are also transferred, through the directional coupler 60b, to the second port 58b of the diversity microcell 54, and are delayed by both delay element 62b and delay element 62a.

For reverse link reception of reverse link signals 12, therefore, the alpha sector

64a provides normal diversity between the R_x antenna 14a and the T_XR_X antenna 14b. The beta sector 64b provides a different time of arrival between the R_x antenna 14a and the T_XR_X antenna 14b, which is equal to the difference in delay on the first path 68a from delay element 62c, and the delay on the second path 68b from delay element 62a and from delay element 62b. For embodiments wherein delay elements 62a,62b,62b, 62d have similar delays (e.g. 1 tau), the second path 68b has twice the delay as the first path 68a for the beta sector 64b.

Similarly, The gamma sector 64c in Figure 5 provides a different time of arrival between the R_x antenna 14a and the T_XR_X antenna 14b, which is equal to the difference in delay on the first path 68a from delay element 62c and 62d, and the delay on the second path 68b from delay element 62a. For embodiments wherein delay elements 62a,62b,62b, 62d have similar delays (e.g. 1 tau), the first path 68a has twice the delay as the second path 68b for the gamma sector

64b.

For embodiments wherein delay elements 62a,62b,62b,62d have similar delays (e.g. 1 tau), a reverse link signal 12 from the R_x antenna 14a of the beta sector 64b arrives at the first port 58a at the same time (e.g. at 1 tau) as the signal 12 from the T_XR_X antenna 14b of the gamma sector 64c arrives at the second port 58b. Similarly, signal 12 from the T_XR_X antenna 14b of the beta sector 64b arrives at the second port 58b at the same time as the signal 12 from the R_x antenna 14a arrives at the second port 58b (e.g. at 2 tau). Therefore, the delay sectorized microcell 50a provides normal diversity for signals within the alpha sector, time delay diversity between signals within each of the secondary sectors 64b,64c, and path diversity for reverse link signals 12 which arrive at the same time from different sectors 64a, 64b,64c.

Figure 6 is a schematic diagram 70 of a alternate basic delay sectorized base transmitter site 50b having discrete directional coupling to primary signal paths

52a, 52b for each of the secondary sectors 64b, 64c. While delays 60 may be cascaded within the delay sectorized base transmitter site 50a shown in Figure 5

(e.g. such as delay element 62c, which operates on reverse-link signals for both the beta sector 64b and the gamma sector 64c), each of the secondary paths 68b may alternately be constructed as separate signal paths, with discrete delays 62 and directional couplers 60. As with the delay sectorized base transmitter site 50a, the alternate basic delay sectorized base transmitter site 50b provides normal reverse link diversity on the primary alpha sector 64a, and time delay reverse link diversity for each of the secondary sectors 64b,64c.

Figure 7 is a graph 72 which displays the time of arrival 74 of reverse link signals 12 at antenna input ports 58a,58b for the diversity sectorized microcell system 50b shown in Figure 6. At a time t=0, processed reverse link signal 78a, resulting from reverse link signal 12 at the R_x antenna 14a of the alpha sector 64a, arrives at the first microcell port 58a. At the same time t=0, processed reverse link signal 78b, resulting from reverse link signal 12 at the T_XR_X antenna 14b of the alpha sector 64a, arrives at the second microcell port 58b. At time t=1 tau, processed reverse link signal 82a, resulting from reverse link signal 12 at the R_x antenna 14a of the gamma sector 64b, arrives at the first microcell port 58a, and processed reverse link signal 80b, resulting from reverse link signal 12 at the

T_XR_X antenna 14b of the beta sector 64b, arrives at the second microcell port

58b. At time t=2 tau, processed reverse link signal 80a, resulting from reverse link signal 12 at the R_x antenna 14a of the beta sector 64b, arrives at the first microcell port 58a, and processed reverse link signal 82b, resulting from reverse link signal 12 at the T_xR_x antenna 14b of the gamma sector 64c, arrives at the second microcell port 58b. Therefore, as with the delay sectorized microcell 50a shown in Figure 5, the alternate delay sectorized microcell 50b shown in Figure 6 provides normal diversity for signals within the alpha sector 64a, time delay diversity between signals within each of the secondary sectors 64b, 64c, and path diversity for reverse link signals 12 which arrive at the same time from secondary sectors 64b,64c.

In a similar manner, various alternate embodiments of delay sectorized microcell 50 provide various combinations of path diversity and time diversity between a primary sector 64a and one or more coupled sectors 64b-64n, such that one or more diversity microcells 54 may be enhanced to provide reverse link and/or forward link CDMA communications to a plurality of sectors 64a-64n.

Figure 8 is a simplified schematic diagram of a delay sectorized microcell 50c having directional coupling to primary signal paths 52a, 52b, same time-of-arrival and normal diversity between reverse-link signals 12 within each sector 64b,64b,64c, and different time-of-arrival for reverse-link paths between each of the sectors 64b,64b,64c. A first alpha sector 64a, having a receive R_x antenna 14a and a transmit receive T_XR_X antenna 14b, is respectively coupled, through a first signal path 52a and a second signal path 52b, to a first microcell port 58a and a second microcell port 58b of a diversity microcell 54 at a delay-sectorized base transmitter site 56. One or more secondary sectors 64b-64n (e.g. such as a beta sector 64b and a gamma sector 64c) are then coupled to the first signal path 52a and a second signal path 52b, using directional couplers 60 {e.g. such as directional couplers 60a,60b).

The delay sectorized microcell 50c provides a different decorrelation between signals 12 within sectors 64b,64c than the delay sectorized microcell 50a shown in Figure 5, in that reverse link signals 12 from R_x antennas 14a and R_XT_X antennas 14b preferably arrive at their respective signal ports 58a,58b at the same time, with normal diversity, for embodiments wherein delay elements 62a,62b,62b,62d have similar delays (e.g. 1 tau).

For reception of reverse link signals 12 at the delay sectorized microcell 50c, a reverse link CDMA 12 typically arrives at both an R_X antenna 14a and a T_XR_X antenna 14b at one or more sectors 64a,64b,64c. As seen in Figure 8, reverse link signals 12 which are received by the R_x antenna 14a at the alpha sector 64a are transferred through the first signal path 52a to the first port 58a of the diversity microcell 54. Input signals 12 which are received by the R_x antenna 14a at the beta sector 64b are also transferred, through the directional coupler 60a, to the first port 58a of the diversity microcell 54, and are delayed by a delay element 62c. Input signals 12 which are received by the R_x antenna 14a at the gamma sector 64c are also transferred, through the directional coupler 60a, to the first port 58a of the diversity microcell 54, and are delayed by both delay element 62c and delay element 62d.

Input signals 12 which are received by the T_XR_X antenna 14b at the alpha sector

64a are transferred through the second signal path 52b to the second port 58b of the diversity microcell 54. Input signals 12 which are received by the T_XR_X antenna 14b at the beta sector 64b are also transferred, through the directional coupler 60b, to the second port 58b of the diversity microcell 54, and are delayed by a delay element 62a. Input signals 12 which are received by the T_XR_X antenna 14b at the gamma sector 64c are also transferred, through the directional coupler 60b, to the second port 58b of the diversity microcell 54, and are delayed by both delay element 62b and delay element 62a.

For reverse link reception of signals, therefore, the alpha sector 64a provides normal diversity between the R_x antenna 14a and the T_XR_X antenna 14b, for embodiments wherein delay elements 62a and 62c have similar delays (e.g. 1 tau), the delay sectorized microcell 50c provides a different time of arrival for the

R_x antenna 14a and for the T_XR_X antenna 14b for the beta sector 64b, as compared to the alpha sector 64a, which is equal to the respective delays 62c, 62a. The delay sectorized microcell 50c also provides a different time of arrival for the R_x antenna 14a and for the T_XR_X antenna 14b for the gamma sector 64c, which is equal to the sums of the cascaded respective delays 62c plus 62d, and

62a plus 62b.

For embodiments wherein delay elements 62a and 62c have similar delays (e.g.

1 tau), the delay sectorized microcell 50c provides the same time of arrival for the R_x antenna 14a and for the T_XR_X antenna 14b within the beta sector 64b. Similarly reverse link signals for the gamma sector arrive at the same time, each having a delay of 2 tau. Therefore, the time of arrival is preferably the same for the R_x antenna 14a and for the T_XR_X antenna 14b within each of the sectors ( e.g. such as for sector 64b), is separated from the time of arrival of the other sectors 64 (e.g. such as for sectors 64a,64c).

Figure 9 is a schematic diagram 71 of an alternate basic delay sectorized base transmitter site 50d having discrete directional coupling to primary signal paths 52a, 52b for each of the secondary sectors 64b, 64c. While delays 62a,62b,62c,62d may be cascaded within the delay sectorized base transmitter site 50c shown in Figure 8 (e.g. such as delay element 62c, which operates on reverse-link signals 12 for both the beta sector 64b and the gamma sector 64c), each of the secondary paths 68b may alternately be constructed as separate signal paths, with discrete delays 62 and directional couplers 60. The alternate basic delay sectorized base transmitter site 50d provides reverse-path delay- sectorization between antenna sectors 64a,64b,64c, and preferably provides same time-of-arrival (i.e. normal diversity) for reverse-link signals 12 within each sector 64a,64b,64c.

Figure 10 is a graph 84 which shows the input signal 86a at a first antenna input ports 58a, and the input signal 86b at a second antenna input port 58b, which indicates the time of arrival 74 of processed reverse link signals 88a, 88b,90a,90b,92a,92b at antenna input ports 58a,58b for the delay-sectorized microcell 50d shown in Figure 9.

Figure 11 is a partial simplified schematic diagram 93 of a base transmitter site having directional coupling 60 to a T_XR_X signal path 52b, and forward-path time diversity between antenna sectors 64a,64b,64c. While delays 62 may be cascaded between forward signal path 52b between sectors, each of the forward paths for secondary sectors 64b,64c may alternately be constructed as separate signal paths, with discrete delays 62 and directional couplers 60. The partial delay sectorized base transmitter site 50e provides forward-path delay- sectorization between antenna sectors 64a,64b,64c. Figure 12 is a graph 94 which shows the transmission 94, as a function of time 74, of processed forward- link signals 98,100,102 at T_XR_X antenna ports 14b at respective sectors

64a,64b,64c for the microcell 50e shown in Figure 11. Detailed Embodiments for Different Delay in Sector. Figure 13 is a detailed schematic diagram of a delay sectorized microcell system 50f at a base transmitter site, having directional coupling to primary signal paths 52a,52b. The delay sectorized microcell system 50f provides same time of arrival for reverse- link signals 12 on different paths (e.g. such as at microcell ports 58a,58b) in- between secondary sectors 64b,64c, and different time-of-arrival for reverse-link signals 12 for each secondary sector 64b,64c.

The first coupled secondary path 68a within the delay sectorized microcell system 50f includes a combiner 106a, which connects the R_x antenna 14a from the beta sector 64b and the reverse link path from the T_XR_X antenna 14b from the gamma sector 64c. The reverse link path from the T_XR_X antenna 14b from the gamma sector 64c also comprises a delay element 62a which provides time delay decorrelation (i.e. diversity) between the reverse link path from the T_XR_X antenna 14b on the gamma sector 64c and the R_x path from the beta sector

64b. A means for gain balancing, such as a variable attenuator 112 on the R_x path from the beta sector 64b, is also preferably included between the combined paths. A second delay element 62b is located between the combiner 106a and the directional coupler 60a on the first coupled secondary path 68a. A means for reverse link gain adjustment 114a is also preferably included between the combiner 106a and the directional coupler 60a on the first coupled secondary path 68a.

The second coupled secondary path 68b within the delay sectorized microcell system 50f includes a duplexor 108a which is coupled to directional coupler 60b on the second primary path 52b. The duplexor 108a separates the forward link portion and the reverse link portions of the second coupled secondary path 68b. The reverse link portion of the second coupled secondary path 68b includes a combiner 106b, which connects the R_x antenna 14a from the gamma sector 64c and the reverse link path from the T_xR_x antenna 14b from the beta sector 64b.

The reverse link path from the T_XR_X antenna 14b from the beta sector 64b also comprises a delay element 62c which provides time delay decorrelation (i.e. diversity) between the reverse link path from the T_XR_X antenna 14b on the beta sector 64b and the R_x path from the gamma sector 64c. Means for gain balancing, such as a variable attenuator 112 on the R_x path of the gamma sector

64c, is also preferably included between the combined paths. A second delay element 62d is located between the combiner 106b and the duplexor 108a on the second coupled secondary path 68b. A means for reverse link gain adjustment 114b is also preferably included between the combiner 106b and the duplexor 108b.

The forward link side of the second coupled secondary path 68b is connected to the T_XR_X antenna 14b on the beta sector 64b. The second coupled secondary path 68b also comprises a directional coupler 60c, which connects the forward link side of the second coupled secondary path 68b to the T_XR_X antenna 14b on the gamma sector 64c. A delay element 62e is located between the duplexor 108a and the directional coupler 60c.

The forward link path also comprises a delay element 62f between the directional coupler 60c and the to the T_XR_X antenna 14b on the gamma sector 64c, which provides time delay decorrelation (i.e. diversity) between the forward link path of the T_XR_X antenna 14b on the beta sector 64b and the forward link path of the

T_XR_X antenna 14b on the gamma sector 64c. The forward link path of the T_XR_X antenna 14b on the beta sector 64b preferably includes a beta sector forward link gain adjustment 112, such as a variable attenuator 112. Similarly, the forward link path of the T_XR_X antenna 14b on the gamma sector 64c preferably includes a gamma sector forward link gain adjustment 112, such as a variable attenuator 112.

For the secondary sectors 64b,64c, the forward paths and the reverse link paths associated with the T_XR_X antennas 14b are separated by duplexors 108b, 108c respectively. The forward link paths for the secondary sectors 64b, 64c preferably include power amplifiers 116. The reverse link paths for the secondary sectors 64b, 64c preferably include receive filters 113 and low noise amplifiers 110.

Gain Balancing. The delay sectorized microcell system 50f preferably provides gain balancing for both reverse link signal paths within each secondary sector 64b,64c, as well as gain balancing between sectors 64a,64b,64c for both reverse link signal paths. Means for gain balancing 112 within the beta sector 64b and the gamma sector 64b are typically adjusted to balance gain between the delayed and non-delayed paths on the combined reverse link paths. As well, the first coupled signal path 68a and the second coupled signal path 68b may be adjusted to balance gain, such as by adjusting variable attenuators 114a and/or 114b as necessary.

In a CDMA delay combining structure, such as between reverse link paths within a sector, or between sectors, the use of a delay 62, such as a SAW filter, typically results in a significant attenuation of a signal 12 passing therethrough. For example, the use of a 2 microsecond 1900 MHz SAW filter 62a within the reverse link path for the gamma sector 64 in the delay sectorized microcell system 50f may typically result in a loss of approximately 28 dB. Similarly, the use of a 4 microsecond SAW delay 62a may typically result in a loss of approximately 56 dB. Therefore, for two incoming independent fading CDMA signals reverse link signals 12, wherein one of the signals 12 passes through the

R_X antenna 14a in the beta sector 64b, while the other signal 12 passes through the T_XR_X antenna 14b in the gamma sector 64c which imparts a delay 62a, the differential attenuation between the two reverse link paths is substantial. Furthermore, when two or more reverse link signals 12, which are not phase coherent, are combined, they appear as noise energy to each other. Upstream noise sources (prior to the combiner 106a) are added together at the combiner 106a, and the total noise is associated with both signals 12. The effect of these two factors is to cause a signal to noise ratio (SNR) imbalance between the combined signals 12. For example, if two signals 12, initially having an equal signal to noise ratio (SNR), are processed and combined, and one signal has an amplitude that is 10 dB below the other, then the SNR of the weaker signal will be approximately 10 dB lower than the other.

Therefore, in a delay combiner system, such as the reverse link path between the beta sector 64b and the gamma sector 64c, having a significant gain imbalance between processing paths, such as introduced by a delay element 62a, the subsequent signal information from the delayed reverse link path may be "lost" during subsequent signal processing (i.e. such a delay combiner would therefore fail to provide SNR improvements, since it fails to increase the number of signals which are available to a rake receiver). It is therefore preferable that the coupled reverse link signal paths connected to each port 58 be gain balanced, such that the diversity microcell 54 can adequately receive and differentiate the arriving delayed and combined reverse link signals 12. For example, the gain is preferably balanced, such that the gain from the R_x antenna 14a in the beta sector 64b to the first port 58a (across point

D to G), the gain from the T_XR_X antenna 14b in the gamma sector 64c to the first port 58a (across point E to G), and the gain from the R_X antenna 14a in the alpha sector 64a to the first port 58a (across point A to G), are matched. Similarly, the reverse link path gain for path C-H, for path F-H, and for B-H are preferably adjusted to match. As well, the forward link paths for the secondary sectors

64b,64c further comprise forward link gain adjustment 112.

For gain balancing of the reverse link paths between sectors 64, such as during the installation of a delay sectorized microcell system 50f, the gain of the first primary path 52a (from A to G) for the alpha sector 64a is typically measured, wherein net gain is typically on the order of under 1 dB. The gains for the coupled reverse-link paths for the secondary sectors 64b, 64c are then preferably adjusted, to match the gain of the primary path 52a, and to balance between the secondary sectors 64b,64c.

Figure 14 is a detailed schematic diagram of a modular delay sectorized microcell system 50g, having two delay combiner modules 120a and an interconnection module 122. The modular delay sectorized microcell system 50g has many similar functional characteristics to the delay sectorized microcell system 50f shown in Figure 13. However the modular delay combiner modules 120a and the modular interconnection module 122 may easily be prepackaged subassemblies. For example, in some preferred embodiments of the modular delay sectorized microcell system 50g, the delay combiner modules 120a are Type OA850C or OA1900C Network Repeaters, available through Repeater Technologies Inc., of Sunnyvale, CA. The delay combiner modules 120a are typically available on either AC or DC power, and are available with either a wireline or wireless RNet interface. A detailed description of delay combiner • modules 120a are described by M. Fuerter, in U.S. Patent Application No. 09/028,434, Delay Combiner System for CDMA Repeaters and Low Noise Amplifiers, filed 24 February 1998, and in U.S. Patent Application No.

09/630,200, Improved Delay Combiner System for CDMA Repeaters and Low Noise Amplifiers, filed 01 August 2000, which are incorporated herein by reference. In some embodiments of the modular delay sectorized microcell system 50g, the diversity microcell 54 is a PCS CDMA communication base station, such as available through Lucent Technologies Inc., of Columbus, OH.

The modular delay sectorized microcell system 50g provides directional coupling 60 to primary signal paths 52a,52b, same time of arrival for reverse-link signals 12 on different paths in-between secondary sectors 64b,64c, and different time- of-arrival for reverse-link paths within each secondary sector 64b and 64c. As discussed above, each of the sectors 64a, 64b, 64c typically has both an R_x antenna 14a and a T_XR_X antenna 14b, which are located at the site of a diversity microcell 54, and are directed to provide forward link transmission and reverse link reception for a plurality of sectors 64a,64b,64c. The sectors 64a,64b,64c are preferably adjustable, both in direction and in azimuth.

Each of the delay combiner modules 120a includes three signal connection ports 130a, 130b, and 130c. A duplexor 108a is connected to the second signal connection port 130b, to separate T_XR_X signal paths within the delay combiner module 120a. A reverse link diversity signal path, preferably having a low noise amplifier 110, and having a delay element 62a is connected to the third signal connection port 130c. A reverse link main signal path, preferably having means for gain balancing 112, is connected to the duplexor 108a. The reverse link main signal path also preferably includes a receive filter 113 and a low noise amplifier

110. A combiner 106 combines the reverse link diversity signal path and the reverse link main signal path, and forwards combined reverse link signals through a delay element 60c (e.g. such as a channel select filter CSF), to a duplexor

108b, which is connected to the first signal connection port 130a. For forward link signals 15, duplexor 108b is also connected to the second signal connection port

130b, through a delay element 62b and through the forward link of duplexor 108a.

The modular interconnection module 122 includes antenna connections 124a, 124b, and 124c, port connections 126a, 126b, and delay combiner module connections 128a, 128b, 128c. The primary signal paths 52a,52b are connected respectively between the alpha sector antennas 14a, 14b and the microcell ports

58a,58b, through port connections 126a, 126b. The first coupled secondary path 68a is coupled to the first primary signal path 52a through the first directional coupler 60a. The first coupled secondary path 68a is connected through the low side of a duplexor 108c, to delay combiner connection 128c. A gain adjustment 114 ( e.g. such as a variable attenuator or a power attenuation device (PAD)) is preferably located between the duplexor 108c and the delay combiner connection 128c. A module signal path 127 is provided between antenna connection 124c and delay combiner connection 128b. The high side of the duplexor 108c is coupled to the module signal path 127, by a third directional coupler 60c.

The second coupled secondary path 68b is coupled to the second primary signal path 52b through the second directional coupler 60b. The second coupled secondary path 68b is also connected to the first delay combiner module connection 128a, and preferably includes a gain adjustment 114 (e.g. such as a variable attenuator or a power attenuation device (PAD)).

The diversity microcell 54 and the delay combiner modules 120a preferably have about the same levels of transmitter output power. The antenna pairs 14a,14b for each of the sectors 64a,64b,64c are preferably directional antennas, which provide some gain over a standard dipole. Therefore, the modular delay sectorized microcell system 50g is able to service three times the service area 22 (FIG. 1), as compared to a standard microcell 20 having a single antenna pair 14a, 14b. As well, the modular delay sectorized microcell system 50g provides the expanded service area 22, at a fraction of the cost of a base station 16 having multiple microcells 20.

In operation, forward link signals 15 from the diversity microcell 54 are delayed between sectors 64a,64b,64c, by the delay combiner modules 120a, and are then transmitted by the T_XR_X antennas 14b for each of the sectors 64a,64b,64c.

For reverse link reception, each of the R_x antennas 14a and T_XR_X antennas 14b contribute reverse link signals 12 from the sectors 64a,64b,64c, which are decorrelated, either across signal paths 52a,52b, or by time delays 60, within the delay sectorization circuitry 66.

The delay combining modules 120a, in conjunction with the interconnection module 122, provide diversity transmission of forward link signals 15 for each of the sectors 64a,64b,64c, normal diversity reception of reverse link signals 12 for the first beta sector 64b, and time delay diversity reception of reverse link signals 12 for the second beta sector 64b and the third gamma sector 64c, such that each of the reverse link signals 12 are decorrelated from each other, either by time delay or by signal paths 52a,52b.

The diversity microcell 54 or base transmitter site 56 typically includes one or more modems 131 , which performs many functions, such as CDMA searching, CDMA modulation and demodulation, and the Viterbi and/or Turbo decoding of signals. The diversity techniques employed in the present invention only work with CDMA systems, since CDMA systems are able to recognize and demultiplex the delay imposed between the paths within the reverse link multipath signal 12. As well, the modem 131 receives forward path signals from the cellular network, and produces forward signals 15 which are transmitted through the forward links toward the mobile transceivers CP. In some embodiments of the diversity microcell 54, the modems 131 at the cell site are Model No. CSM 2000 or Model No. CSM 5000, available through QualComm, Inc. of San Diego, CA.

The delay sectorized microcell system 50f, as well as the modular delay sectorized microcell system 50g, are typically used for diversity microcells 54 wherein both the R_x port 58a and the Tx/Rx port 58b are independently searched for reverse link signals 12, such as typically performed by the modem 131 associated with the microcell 54 at the cell site. As both the R_x port 58a and the T_xR_x port 58b are searched, the differences in processing delays (e.g. such as by delay elements 62) between reverse link signals 12 arriving at the R_x and

T_XR_X antenna ports 58a,58b for the secondary sectors (e.g. such as for sectors

64b, 64c) does not adversely effect the receipt of delayed and non-delayed reverse link signals. In the modular delay sectorized microcell system 50g, therefore, identical delay combiner modules 120a (which provide time delay diversity between R_x and T_XR_X antenna paths for secondary sectors 64b, 64c) may be used.

While the delay sectorized microcell system 50f, as well as the modular delay sectorized microcell system 50g, provide time delay diversity for reverse link signals 12 between R_x and T_XR_X antenna pairs 14a, 14b, the reverse link signals are processed separately within the delay sectorization circuitry 66, and are typically shifted back into phase within a rake receiver at the diversity microcell, such that diversity information between the two reverse link signals 12 is retained and used.

Detailed Embodiments for Normal Diversity in Sector. Figure 15 is a detailed schematic diagram of a delay sectorized microcell system 50h having directional coupling to primary signal paths 52a,52b, differential reverse-link and forward-link delays between sectors 64a,64b,64c, and same time-of-arrival for processed reverse-link signals 12 on different microcell ports 58a,58b for each of a plurality of sectors 64a,64b,64c.

The first coupled secondary path 68a within the delay sectorized microcell system 50h includes a combiner 106a, which connects the R_x antenna 14a from the beta sector 64b and the reverse link path from the T_XR_X antenna 14b from the gamma sector 64c. The reverse link path from the R_X antenna 14a from the beta sector 64b also comprises a delay element 62a which provides time delay decorrelation (i.e. diversity) between the R_x path from the beta sector 64b and the reverse link path from the T_xR_x antenna 14b on the gamma sector 64c. A means for gain balancing, such as a variable attenuator 112 on the reverse link path from the T_XR_X antenna 14b from the beta sector 64b, is also preferably included between the combined paths. A second delay element 62b is located between the combiner 106a and the directional coupler 60a on the first coupled secondary path 68a. A means for beta sector reverse link gain adjustment 112 is also preferably included on the reverse link path from the R_x antenna 14a, such that the overall gain adjustment, as well as gain balancing, may be performed on the first coupled signal path 68a. In alternate embodiments (e.g. such as shown in Figure 13), a combined gain adjustment 114a may preferably be incorporated on the first coupled secondary path 68a.

The second coupled secondary path 68b within the delay sectorized microcell system 50h includes a duplexor 108a which is coupled to directional coupler 60b on the second primary path 52b. The duplexor 108a separates the forward link portion and the reverse link portions of the second coupled secondary path 68b. The reverse link portion of the second coupled secondary path 68b includes a combiner 106b, which connects the R_x antenna 14a from the gamma sector 64c and the reverse link path from the T_XR_X antenna 14b from the beta sector 64b.

The reverse link path from the T_XR_X antenna 14b from the beta sector 64b also comprises a delay element 62c, which provides time delay decorrelation (i.e. diversity) between the reverse link path from the T_XR_X antenna 14b on the beta sector 64b and the R_X path from the gamma sector 64c. Means for gain balancing, such as a variable attenuator 112 on the R_x path of the gamma sector

64c, is also preferably included between the combined paths. A second delay element 62d is located between the combiner 106b and the duplexor 108a on the second coupled secondary path 68b. The reverse link path from the T_xR_x antenna 14b from the beta sector 64b also preferably includes gain adjustment

112. In an alternate embodiment, means for reverse link gain adjustment 114b is also preferably included between the combiner 106b and the duplexor 108a, as seen in Figure 13.

The forward link side of the second coupled secondary path 68b is connected to the T_XR_X antenna 14b on the beta sector 64b. The second coupled secondary path 68b also comprises a directional coupler 60c, which connects the forward link side of the second coupled secondary path 68b to the T_XR_X antenna 14b on the gamma sector 64c.

A delay element 62e is located between the duplexor 108a and the directional coupler 60c, wherein the delay element provides time delay decorrelation (i.e. diversity) between the T_XR_X antenna 14b on the alpha sector 64a, and the forward link paths of the T_XR_X antenna 14b on the beta sector 64b and the T_XR_X antenna 14b on the gamma sector 64c. The forward link path to the T_XR_X antenna 14b on the gamma sector 64c also comprises a delay element 62f which provides additional time delay decorrelation (i.e. diversity) between the forward link path of the T_XR_X antenna 14b on the beta sector 64b and the forward link path of the T_XR_X antenna 14b on the gamma sector 64c.

For the secondary sectors 64b,64c, the forward paths and the reverse link paths associated with the T_XR_X antennas 14b are separated by duplexors 108b, 108c respectively. The forward link paths for the secondary sectors 64b, 64c preferably include power amplifiers 116. The reverse link paths for the secondary sectors 64b,64c preferably include receive filters 113 and low noise amplifiers 110.

The forward link path of the T_XR_X antenna 14b on the beta sector 64b preferably includes a beta sector forward link gain adjustment 112, such as a variable attenuator 112. Similarly, the forward link path of the T_XR_X antenna 14b on the gamma sector 64c preferably includes a gamma sector gain adjustment 112, such as a variable attenuator 112.

The forward gain for each of the secondary sectors 64b, 64c may be adjusted independently, such as adjusting the beta sector power adjust 112, and/or by adjusting the gamma sector power adjust 112. For example, for a delay sectorized microcell system 50h located along a highway corridor HWY (FIG. 2), wherein the beta sector 64b ia substantially aligned with the highway HWY and one or more mobile telephones CP, the beta sector power adjust 112 may be adjusted to provide a relatively large gain, to extend the transmission of forward link signals for the beta sector 64b. Similarly, for the gamma sector 64c shown in Figure 15, the forward link power output for the T_XR_X antenna is preferably adjusted, such as to extend the service area 22 for the gamma sector 64c. Therefore, the output power for the transmission of forward link signals 15 may be adjusted independently for each of the sectors 64a, 64b, and 64c.

As described above, the magnitude of the delay elements 62 for forward link operation and for the reverse link operation is preferably equal to or greater than two chips. For forward link operation, the delay separation from delay elements

62e,62f provides adequate time delay decorrelation between forward link signals 15 from neighboring sectors 64a,64b,64c, such that the forward signals may arrive at a remote transceiver CP independently from each other, and such that the delay sectorized microcell system 50h may provide passively soft handoff for these forward link signals 15, as a mobile user MU moves between sectors

64a,64b,64c. In the delay sectorized microcell system 50h shown in Figure 15, delay pairs, such as delay elements 62a and 62b, and delay elements 62c and 62d, function as a cascade on the reverse link. Similarly, delay pair 62e and 62f function as a cascade on the forward link. In all embodiments of the delay sectorized microcell system 50, each of the plurality of sectors 64a-64n (e.g. such as sectors 64a, 64b, 64c) are mutually decorrelated from each other. For the forward link, a mobile transceiver CP in the field sees each of the forward paths 15, since the signal 15 arrive at different times from each other. As a mobile user MU, having a mobile transceiver CP, moves within a delay sectorized cell, or for a building or for terrain TE which provides a large reflection, the mobile transceiver CP can still see forward link signals 15 from each of the sectors 64a,64b,64c, since the forward signals 15 corresponding to each of the sectors 64a,64b,64c are decorrelated from each other (i.e. there is diversity between the time of arrival for the forward signals 15 from each of the sectors 64a,64b,64c).

Figure 16 is a detailed schematic diagram of a modular delay sectorized microcell system 50i, having delay combiner modules 120a, 120b and an interconnection module 122. Figure 17 is a basic interconnection diagram for a modular delay sectorized microcell system 50i, having delay combiner modules 120a, 120b and an interconnection module 122 interconnected to a diversity microcell 54. Figure 18 is a perspective view of a modular delay sectorized microcell system 50i. The modular delay sectorized microcell system 50i has many similar functional characteristics to the delay sectorized microcell system 50h shown in Figure 14.

However the modular delay combiner modules 120a, 120b and the modular interconnection module 122 may easily be prepackaged subassemblies. For example, in some preferred embodiments of the modular delay sectorized microcell system 50g, the delay combiner module 120a is a Type OA850C or Type OA1900C Network Repeater, and the delay combiner module 120b is a modified Type OA850C or Type OA1900C Network Repeater, which are available through Repeater Technologies Inc., of Sunnyvale, CA, and are described above. In some embodiments of the modular delay sectorized microcell system 50i, the diversity microcell 54 is a PCS CDMA communication base station, available through Lucent Technologies Inc., of Columbus, OH.

The modular delay sectorized microcell system 50i provides directional coupling 60 to primary signal paths 52a,52b, time delay decorrelation between reverse- link signals between sectors 64a,64b,64c, and same time-of-arrival for reverse- link paths within each sector 64a,64b,64c. As discussed above, each of the sectors 64a,64b,64c typically has both an R_x antenna 14a and a T_XR_X antenna

14b, which are located at the site of a diversity microcell 54, and are directed to provide forward link transmission and reverse link reception for a plurality of sectors 64a,64b,64c. The sectors 64a,64b,64c are preferably adjustable, both in direction and in azimuth.

As described above, the modular interconnection module 122 includes antenna connections 124a, 124b, and 124c, microcell port connections 126a,126b, and delay combiner module connections 128a, 128b, 128c. The primary signal paths 52a, 52a are connected respectively between the alpha sector antennas 14a, 14b and the microcell ports 58a,58b, through microcell port connections 126a, 126b. The internal configuration of the modular interconnection module 122 is described above, in reference to the modular delay sectorized microcell system 50g.

Each of the delay combiner modules 120a, 120b include three signal connection ports 130a, 130b, and 130c. A duplexor 108a is connected to the second signal connection port, to separate T_XR_X signal paths within the delay combiner modules 120a, 120b. Construction of the first delay combiner module 120a is described above in context to modular delay sectorized microcell system 50g. Construction of the second delay combiner module 120b is similar to that of the first delay combiner module 120a, except that the delay element 62a and the means for gain balancing 112 are located on opposite reverse link paths. The use of the delay combiner modules 120a, 120b, as shown in Figure 16, preferably provides the same processing delay between signals arriving at the R_x and T_XR_X antenna ports 58a,58b for each of the secondary sectors 64b,64c, such as for delay elements 62a,62b which have equal time delays (e.g. 1 tau).

The diversity microcell 54 and the delay combiner modules 120a preferably have about the same levels of transmitter output power. The antenna pairs 14a, 14b for each of the sectors 64a,64b,64c are preferably directional antennas, which provide some gain over a standard dipole. Therefore, the modular delay sectorized microcell system 50g is able to service three times the area 22 (FIG. 1), as compared to a standard microcell 20 having a single antenna pair 14a, 14b. As well, the modular delay sectorized microcell system 50g provides an expanded service area 22, at a fraction of the cost of a base station 16 having multiple microcells 20. In operation, forward link signals 15 from the diversity microcell 54 are delayed for secondary sectors 64b, 64c, by the one or both delay elements 62b, within delay combiner modules 120a, 120b, and are then transmitted by the T_XR_X antennas 14b for each of the sectors 64a,64b,64c. For reverse link reception, each of the R_x antennas 14a and T_XR_X antennas 14b contribute reverse link signals 12 from the sectors 64a,64b,64c, which are decorrelated, either across signal paths 52a,52b, or by time delays 62, within the delay sectorization circuitry 66.

The delay combining module circuitry 120a, 120b, in conjunction with the interconnection module 122, provide diversity transmission of forward link signals 15 for each of the sectors 64a,64b,64c, normal diversity reception of reverse link signals 12 for each of the sectors 64a, 64b, 64c, and time delay diversity reception of reverse link signals 12 between the sectors 64a,64b,64c, such that each of the reverse link signals 12 are decorrelated from each other, either by time delay or by signal paths 52a,52b.

The delay sectorized microcell system 50h, as well as the modular delay sectorized microcell system 50i, may be used for a wide variety of diversity microcells 54. For applications in which a modem 131 at the base transmitter site

56 may search only one of the ports 58 (e.g. port 58a) to determine the time of arrival of reverse link signals, a difference in processing delay between signals arriving at the R_X and T_XR_X antenna ports 14a,14b at secondary sectors 64b, 64c may result in loss of signal information from an unsearched port 58 (e.g. such as port 58b). However, the delay sectorized microcell system 50h, as well as the modular delay sectorized microcell system 50i, preferably provide a similar processing delay for reverse link signals 12 signals arriving at the R_x and T_XR_X antenna ports 58a,58b for each of the sectors 64a,64b,64c. Therefore, even for applications in which a modem 131 at the base transmitter site 56 may search only one of the ports 58 (e.g. port 58a) to determine the time of arrival of reverse link signals, the modem 131 properly receives both processed reverse link signals 12 for each of the plurality of sectors 64a,64b,64c.

Forward Link Operation. As seen in Figure 16, the delay sectorization circuitry 66 provides full decorrelation of forward link signals 15 transmitted from all three sectors 64a,64b,64c. Specifically, a transmitter signal 15 that appears at the output of the T_XR_X port 58b of the diversity microcell 54 travels on the second primary signal path 52b, through the directional coupler 60a, to the T_XR_X antenna

14b in the primary alpha sector 64a of the three-sector antenna array. A copy of the forward link signal 15 is taken from the directional coupler 60a, through to the donor port 130a of the first delay combine module 120a. An internal delay element 62b causes a transmit signal 15 that has been decorrelated (e.g. such as by two chips, or approximately six microseconds) to appear at the main output port 130b of the first delay combine module 120a. The forward signal 15 is fed to the T_XR_X antenna 14b in the beta sector 64b, through the directional coupler 60c. A copy of this forward signal 15 is obtained from the directional coupler 60c, which passes through the duplexor 108c, and through the attenuator 114, to the donor port 130a of the second delay combine module 120b. An internal delay element 62b provides a third transmit signal 15, that has been decorrelated ( e.g. such as by an additional two chips, or approximately six microseconds) to appear at the main output port 130b of the second delay combine module

120b. The further delayed forward link signal 15 is then fed to the T_XR_X antenna

14b in the gamma sector 64c.

As a consequence, a very soft hand-off can be accomplished from sector-to- sector, because the lack of coherent outputs amongst the plurality of sectors 64 eliminates fringes and nulls in mobile reception coverage within the whole

While a first forward link signal 15 from one sector (e.g. such as from an alpha sector 64a) may occasionally be reflected and delayed (e.g. such as by terrain or buildings TE) before reaching a mobile transceiver CP, and may occasionally arrive at a remote transceiver CP at close to the same time as a forward signal 15 sent from another sector (e.g. such as from a beta sector 64b), the arriving first signal 15 will appear as multipath fading to forward signals 15 sent from other sectors 64, and the first signal 15 will maintain diversity between signals 15 transmitted from the other sectors 64b,64c. As well, a reflected signal path 15 will typically be very small, whereas the direct paths 15 will be very strong.

Reverse Link Operation. As seen in Figure 16, the delay sectorization circuitry 66 also provides for true diversity between the R_x and T_XR_X signal paths for each of the three sectors 64a,64b,64c. For reception, any alpha sector receive signals 12 are fed directly from R_x antenna 14a and T_XR_X antenna 14b to the respective ports 58a,58b on the diversity microcell 54. The beta sector reverse link signals 12 from T_XR_X antenna 14b are received at the second (i.e. main) port

130b of the first delay combine module 120a. The gamma sector receive signals from R_x antenna 14a are received at the third (i.e. diversity) port 130c of the first delay combine module 120a. Both of these reverse link signals 12 are typically amplified, and forwarded back through the attenuator 114 and the directional coupler 60b into the T_XR_X port 58b of the diversity microcell 54.

Similarly, the beta sector receive signals 12 from R_X antenna 14a are received at the third port 130c of the second delay combine module 120b. The gamma sector receive signals 12 from T_XR_X antenna 14b are received at the second port

130b of the second delay combine module 120b. Both of these reverse link signals 12 are typically amplified, and forwarded back through the attenuator 114, duplexor 108c, and the directional coupler 60a, into the R_x port of the diversity microcell 54. The attenuators 114 within the interconnection module 122 attenuate the rather strong output signals of the diversity microcell and delay combine modules 120a, 120b, and not the relatively weak receive-antenna signals 12.

As described above, gain balancing is preferably used in different embodiments of the delay sectorized microcell systems 50, between the combined reverse link paths, to minimize the noise figure, and to maximize performance between sectors 64. For example, for a mobile user MU that is in between sectors 64a,64b,64c, the preferred use of gain balancing provides a softer handoff for the forward link signals 15.

For reverse link operation, gain balancing is preferably provided between the T_x and T_xR_x antennas 14a, 14b for each sector 64 (e.g. such as for sector 64b), such that received reverse link signals 12 may retain diversity during subsequent processing at the diversity microcell 54.

For each antenna pair (e.g. 14a, 14b) within a sector 64, the reverse link signals are mapped to the two BTS antenna ports, thus preserving true diversity between the received signals for each sector 64, while providing decorrelation between signals from each of the sectors 64. As well, in preferred embodiments, each of the paths corresponding to an antenna pair are similarly processed by delay circuits. A key attribute of the repeater-based delay-sectorized microcell system 50 is the delay combine circuitry (e.g. such as within each of the delay combine modules 120) within the delay sectorization circuitry 66, which time multiplexes two reverse link paths onto one RF path ( e.g. such as by delay element 62a and combiner 106 within each of the delay combine modules 120), and a means for gain balancing 112.

Alternate Embodiments. A wide variety of alternate embodiments of the microcell delay-sectorization system 50 may be configured to provide forward link and or reverse link communications. Figure 19 shows a cloverleaf sector configuration diagram for a delay-sectorization system 50, having a two sectored microcell 54 or base transmitter site 56, which services two primary sectors 64a and 64a', coupled with delay sectorization circuitry 66 to provide service to secondary sectors 64b,64c. Figure 20 shows a three sector configuration diagram for a delay-sectorization system 50, having a single microcell 54 or base transmitter site 56, coupled with delay sectorization circuitry 66 to provide service to secondary sectors 64b,64c. Figure 21 shows a multiple sector configuration diagram for a delay-sectorzation system 50, having a microcell 54 or base transmitter site 56, coupled with delay sectorization circuitry 66 to provide service to a plurality of secondary sectors 64b-64n.

As well, as described above, existing delay combiner repeater modules, such as Type OA850C or OA1900C Network Repeaters, available through Repeater Technologies Inc., of Sunnyvale, CA, may be used as a delay combiner module 120a within modular embodiments of the microcell delay- sectorization systems 50g,50i, and may be reconfigured to provide a modified delay combiner module 120a within a modular microcell delay-sectorization system 50i. Figure 22 is a schematic diagram of an existing OAC diversity repeater, and modifications to provide a modified delay combiner module 120a within a modular microcell delay-sectorization system 50i.

In alternate embodiments of the delay-sectorization system 50, the delay elements 62 may alternately be located elsewhere between the primary sector 64a and secondary sectors 64b-64n, to provide decorrelation between reverse link signals 12 and forward link signal 15. However, delays 62 are not typically located the primary paths 52a,52b, since the signal power on the primary paths 52a,52b is typically high-powered RF energy. Therefore, the primary paths 52a,52b would typically require attenuation of the signals 12,15 to a base band level, with processing through delays 62, and subsequent amplification through a power amplifier. It is therefore typically preferable that delay sectorization circuitry 66 include delays 62 on the secondary paths 68a, 68b, and be coupled to primary paths 52a, 52b through directional couplers 60.

System Advantages. The delay sectorization microcell system 50 adds one or more R_x and T_XR_X antenna pairs 14a, 14b to circuitry for a microcell 54, thereby providing a multiple sector microcell structure which economically provides high quality reverse link and forward link communications for an expanded service area. Some embodiments of a three sector delay sectorization microcell system 50 provide approximately an 85 percent increase in coverage, at 7 watts per sector 64.

The delay sectorization microcell system 50 also provides a system lower noise figure than conventional microcells 20 or base transmitters sites 16 which use power dividing structures.

The delay sectorization microcell system 50 retains either normal or time delay diversity reception for each of the plurality of reverse link R_x and T_XR_X antenna pairs 14a, 14b with each sector 64,and provides either time or path diversity between reverse link signals 12 between the plurality of sectors 64a-64n.

As well, the delay sectorization microcell system 50 provides time delay diversity between forward link signals 15 between each of the plurality of sectors, which eliminates antenna pattern fringing, and provides a soft passive handoff between sectors 64a-64n.

The delay sectorization microcell system 50 also significantly increases the footprint for a diversity microcell 54 at a base transmitter site 56, and provides complete (i.e. 100 percent sectorization) efficiency, as compared to approximately 85 percent for a conventional base transmitter site 16. Sectorization efficiency is the ration of idealized capaciy improvement due to spatial filtering (i.e. Coverage area sectorization) to the theoretical capacity improvement. For example, when a coverage area is sectorized into 3 sectors, there should be a three-time improvement in capacity due to perfect spatial isolation of the three separate sectors, in reality 2.55-time is achieved. The delay sectorization microcell system 50 also preferably provides independent antenna pattern selection, orientation, and tilt.

Although the delay sectorization system 50 and its methods of use are described herein in connection with CDMA microcells and base transmitter sites, the apparatus and techniques can be implemented within omni-directional base stations, as well as within other communications devices and systems, or any combination thereof, as desired.

Accordingly, although the invention has been described in detail with reference to a particular preferred embodiment, persons possessing ordinary skill in the art to which this invention pertains will appreciate that various modifications and enhancements may be made without departing from the spirit and scope of the claims that follow.

Claims

CLAIMSWhat is claimed is:

1. A system, comprising: a first delay combiner module and a second delay combiner module, each of said delay combiner modules comprising a first port, a second port, and a third port, a first reverse link path connected between said third port and a combiner and comprising a first delay element, a first duplexor connected to said second port, a second reverse link path connected between said duplexor and said combiner, means for balancing differential gain between said first reverse link path and said second reverse link path, a second duplexor connected to said first port, a third reverse link path between said combiner and said second duplexor and comprising a second delay element, and a forward link path between said second duplexor and said first duplexor comprising a third delay element; and an interconnection module comprising a first antenna connection, a second antenna connection, and a third antenna connection, a first port connection and a second port connection, a first delay combiner module connection, a second delay combiner module connection, and a third delay combiner module connection, a first primary signal path connected between said first antenna connection and said first port connection, a second primary signal path connected between said second antenna connection and said second port connection, a module signal path connected between said third antenna connection and said second delay combiner module connection, a first directional coupler on said first primary path directionally coupled to said first port connection, a second directional coupler on said second primary path directionally coupled to said second port connection, a third directional coupler on said module signal path directionally coupled to said second delay combiner module connection, a first coupled secondary path comprising a duplexor connected between said first directional coupler and said third directional coupler, said duplexor connected to said third delay combiner module connection, and a second coupled secondary path between said second directional coupler and said first delay combiner module connection; wherein said first delay combiner module connection is connected to said first port on said first delay combiner module, said second delay combiner module connection is connected to said second port on said first delay combiner module, and said third delay combiner module connection is connected to said first port on said second delay combiner module.

2. The system of Claim 1 , said first coupled secondary path of said interconnection module further comprising: means for gain adjustment between said duplexor and said third delay combiner module connection.

3. The system of Claim 1 , said second coupled secondary path of said interconnection module further comprising: means for gain adjustment between said second directional coupler and said first delay combiner module connection.

4. The system of Claim 1 , further comprising: a CDMA microcell having a first port connected to said first port connection of said interconnection module, and a second port connected to said second port connection of said interconnection module.

5. The system of Claim 1 , further comprising: an antenna array comprising a first antenna pair, a second antenna pair and a third antenna pair, each of said antenna pairs comprising an Rx antenna and a Tx/Rx antenna; wherein said Rx antenna of said first antenna pair is connected to said first antenna connection on said interconnection module, said Tx/Rx antenna of said first antenna pair is connected to said second antenna connection on said interconnection module, said Tx/Rx antenna of said second antenna pair is connected to said third antenna connection on said interconnection module, said Rx antenna of said second antenna pair is connected to said third port on said second delay combiner module, said Rx antenna of said third antenna pair is connected to said third port on said first delay combiner module, and said Tx/Rx antenna of said third antenna pair is connected to said second port on said second delay combiner module.

6. The system of Claim 5, wherein said antenna array radially divides a microcell service area into a first sector, a second sector, and a third sector, in which said first antenna pair is directed to said first sector, said second antenna pair is directed to said second sector, and said third antenna pair is directed to said third sector.

7. The system of Claim 1 , wherein each of said delay combiner modules further comprises: an amplifier on said first reverse link path between said third port and said combiner.

8. The system of Claim 1 , wherein each of said delay combiner modules further comprises: an amplifier on said second reverse link path between said first duplexor and said combiner.

9. The system of Claim 1 , wherein each of said delay combiner modules further comprises: an amplifier on said forward link path between said second duplexor and said first duplexor.

10. The system of Claim 1 , wherein each of said delay combiner modules further comprises: means for gain adjustment on said forward link path between said second duplexor and said first duplexor.

11. The system of Claim 1 , wherein said first delay element for each of said delay combiner modules has a delay of at least one chip.

12. The system of Claim 1 , wherein said second delay element for each of said delay combiner modules has a delay of at least one chip.

13. The system of Claim 1 , wherein said third delay element for each of said delay combiner modules has a delay of at least one chip.

14. The system of Claim 1 , wherein said first delay element and said second delay element for each of said delay combiner modules have an equivalent delay.

15. A system, comprising: a first delay combiner module comprising a first port, a second port, and a third port, a first reverse link path connected between said third port and a combiner and comprising a first delay element, a first duplexor connected to said second port, a second reverse link path connected between said duplexor and said combiner, means for balancing differential gain between said first reverse link path and said second reverse link path, a second duplexor connected to said first port, a third reverse link path between said combiner and said second duplexor and comprising a second delay element, and a forward link path between said second duplexor and said first duplexor comprising a third delay element; a second delay combiner module comprising a first port, a second port, and a third port, a first reverse link path connected between said third port and a combiner, a first duplexor connected to said second port, a second reverse link path connected between said duplexor and said combiner and comprising a first delay element, means for balancing differential gain between said first reverse link path and said second reverse link path, a second duplexor connected to said first port, a third reverse link path between said combiner and said second duplexor and comprising a second delay element, and a forward link path between said second duplexor and said first duplexor comprising a third delay element; and an interconnection module comprising a first antenna connection, a second antenna connection, and a third antenna connection, a first port connection and a second port connection, a first delay combiner module connection, a second delay combiner module connection, and a third delay combiner module connection, a first primary signal path connected between said first antenna connection and said first port connection, a second primary signal path connected between said second antenna connection and said second port connection, a module signal path connected between said third antenna connection and said second delay combiner module connection, a first directional coupler on said first primary path directionally coupled to said first port connection, a second directional coupler on said second primary path directionally coupled to said second port connection, a third directional coupler on said module signal path directionally coupled to said second delay combiner module connection, a first coupled secondary path comprising a duplexor connected between said first directional coupler and said third directional coupler, said duplexor connected to said third delay combiner module connection, and a second coupled secondary path between said second directional coupler and said first delay combiner module connection; wherein said first delay combiner module connection is connected to said first port on said first delay combiner module, said second delay combiner module connection is connected to said second port on said first delay combiner module, and said third delay combiner module connection is connected to said first port on said second delay combiner module.

16. The system of Claim 15, said first coupled secondary path of said interconnection module further comprising: means for gain adjustment between said duplexor and said third delay combiner module connection.

17. The system of Claim 15, said second coupled secondary path of said interconnection module further comprising: means for gain adjustment between said second directional coupler and said first delay combiner module connection.

18. The system of Claim 15, further comprising: a CDMA microcell having a first port connected to said first port connection of said interconnection module, and a second port connected to said second port connection of said interconnection module.

19. The system of Claim 15, further comprising: an antenna array comprising a first antenna pair, a second antenna pair and a third antenna pair, each of said antenna pairs comprising an Rx antenna and a Tx/Rx antenna; wherein said Rx antenna of said first antenna pair is connected to said first antenna connection on said interconnection module, said Tx/Rx antenna of said first antenna pair is connected to said second antenna connection on said interconnection module, said Tx/Rx antenna of said second antenna pair is connected to said third antenna connection on said interconnection module, said

Rx antenna of said second antenna pair is connected to said third port on said second delay combiner module, said Rx antenna of said third antenna pair is connected to said third port on said first delay combiner module, and said Tx/Rx antenna of said third antenna pair is connected to said second port on said second delay combiner module.

20. The system of Claim 19, wherein said antenna array radially divides a microcell service area into a first sector, a second sector, and a third sector, in which said first antenna pair is directed to said first sector, said second antenna pair is directed to said second sector, and said third antenna pair is directed to said third sector.

21. The system of Claim 15, wherein said first delay combiner module further comprises: an amplifier on said first reverse link path between said third port and said combiner.

22. The system of Claim 15, wherein said second delay combiner module further comprises: an amplifier on said first reverse link path between said third port and said combiner.

23. The system of Claim 15, wherein said first delay combine module further comprises: an amplifier on said second reverse link path between said first duplexor and said combiner.

24. The system of Claim 15, wherein said second delay combine module further comprises: an amplifier on said second reverse link path between said first duplexor and said combiner.

25. The system of Claim 15, wherein said first delay combine module further comprises: an amplifier on said forward link path between said second duplexor and said first duplexor.

26. The system of Claim 15, wherein said second delay combine module further comprises: an amplifier on said forward link path between said second duplexor and said first duplexor.

27. The system of Claim 15, wherein said first delay combine module further comprises: means for gain adjustment on said forward link path between said second duplexor and said first duplexor.

28. The system of Claim 15, wherein said second delay combine module further comprises: means for gain adjustment on said forward link path between said second duplexor and said first duplexor.

29. The system of Claim 15, wherein said first delay element for each of said delay combiner modules has a delay of at least one chip.

30. The system of Claim 15, wherein said second delay element for each of said delay combiner modules has a delay of at least one chip.

31. The system of Claim 15, wherein said third delay element for each of said delay combiner modules has a delay of at least one chip.

32. The system of Claim 15, wherein said first delay element and said second delay element for each of said delay combiner modules have an equivalent delay.

33. A system, comprising: a first primary sector comprising a first primary signal path between a first primary antenna connection and a first primary CDMA port connection, and a second primary signal path between a second primary antenna connection and a second primary CDMA port connection; at least one secondary sector comprising a first secondary signal path comprising a first secondary antenna connection directionally coupled to said first primary CDMA port connection, and a second secondary signal path comprising a second secondary antenna connection directionally coupled to said second primary CDMA port connection; wherein each of said first secondary signal paths for each of said at least one secondary sector are time delay decorrelated from said first secondary signal paths for other of said at least one secondary sector and from said first primary signal path; and wherein each of said second secondary signal paths for each of said at least one secondary sector are time delay decorrelated from said second secondary signal paths for other of said at least one secondary sector and from said second primary signal path.

34. The system of Claim 33, wherein said first secondary signal paths are time delay decorrelated from said second secondary signal paths within each of said at least one secondary sector.

35. The system of Claim 33, wherein said first secondary signal paths and said second secondary signal paths within each of said at least one secondary sector are similarly time decorrelated.

36. The system of Claim 33, wherein each of said at least one secondary sector further comprises: a forward link signal path directionally coupled to said second primary CDMA port connection and connected to said second secondary antenna connection; wherein each of said forward link signal paths for each of said at least one secondary sector are time delay decorrelated from said forward link signal paths for other of said at least one secondary sector and from said second primary signal path of said first primary sector.

37. The system of Claim 33, further comprising: a CDMA microcell having a first port connected to said first primary CDMA port connection, and a second port connected to said second primary CDMA port connection.

38. The system of Claim 33, further comprising: means for gain balancing between said first secondary signal path and said second secondary signal path for each of said at least one secondary sector.

39. The system of Claim 33, further comprising: means for gain adjustment on said first secondary signal path of each of said at least one secondary sectors.

40. The system of Claim 33, further comprising: means for gain adjustment on said second secondary signal path of each of said at least one secondary sectors.

41. A apparatus, comprising: a three-sector antenna array, comprising an alpha sector antenna pair for receiving radio signals from a first sector, a beta sector antenna pair for receiving radio signals from a second sector, and a gamma sector antenna pair for receiving radio signals from a third sector; and a diversity-sectorization circuit connected to route said radio signals from all sectors to a base transmitter site (BTS) and for preserving a main and a diversity receiver signal path from each of the alpha, beta, and gamma sector antenna pairs through to said BTS.

42. The apparatus of claim 41 , wherein: said alpha sector antenna pair comprises a first Tx/Rx antenna for transmitting a radio signal from said BTS to said first sector; said beta sector antenna pair includes a second Tx/Rx antenna for transmitting a chip-delayed radio signal from said BTS with a first time-delay to said second sector; and said gamma sector antenna pair includes a third Tx/Rx antenna for transmitting a chip-delayed radio signal from said BTS with a second time-delay to said third sector.

43. The apparatus of claim 42, further comprising: a first delay combiner module connected to amplify said radio signal from said BTS and to output an amplified version of said chip-delayed radio signal from said BTS with said first time-delay to said second Tx/Rx antenna.

44. The apparatus of claim 42, further comprising: a second delay combiner module connected to amplify said radio signal from said BTS and to output an amplified version of said chip-delayed radio signal from said BTS with said second time-delay to said third Tx/Rx antenna.

45. The apparatus of claim 43, further comprising: a second delay combiner module connected to an output of the first delay combiner module for amplifying said chip-delayed radio signal with said second time-delay to said third Tx/Rx antenna.

46. The apparatus of claim 42, further comprising: a first directional coupler connected between said BTS and said first Tx/Rx antenna; and a first delay combiner module connected to amplify a first signal from the first directional coupler and to output an amplified version of said chip-delayed radio signal with said first time-delay to said second Tx/Rx antenna.

47. The apparatus of claim 42, further comprising: a second directional coupler connected between said first delay combiner module and said second Tx/Rx antenna; a third directional coupler connected between a diversity input port (Rx) of said BTS and a first diversity Rx antenna included in the alpha sector antenna pair; a duplexor connected across the second and third directional couplers and having a duplexor antenna port; and a second delay combiner module connected to amplify a second signal from said duplexor antenna port and to output an amplified version of said chip- delayed radio signal with said second time-delay to said third Tx/Rx antenna.