WO2004040802A1

WO2004040802A1 - A wireless repeater with a built in channel rf/if signal synthetic structure for cancelling interference

Info

Publication number: WO2004040802A1
Application number: PCT/KR2002/002212
Authority: WO
Inventors: Chang Wook Lee; Jae Sung Bae
Original assignee: Innoace Co., Ltd.
Priority date: 2002-10-31
Filing date: 2002-11-26
Publication date: 2004-05-13
Also published as: AU2002353637A1; KR20040038383A

Abstract

In accordance with this invention, a Wireless Repeater comprises a signal input part, a transmission composing part and a composing part that has two composer, one composer of the composing part receives N number of signal from the input signal part without phase modulation, the other has a characteristic of removing original signal of N number of signal from the input signal part by modulating the received signals phase to inverse phase through the formation of a transmission composing part, having a composer and transmission conduits of equal or inverse phase. Accordingly, it is an object of the present invention to provide improved Repeaters of removing interference signal by means of phase modulation, overcoming exisiting problem of decreasing ability of destructing interference signal and removing partially original signals.

Description

A Wireless Repeater with a Built in Channel RF/IF signal synthetic structure for cancelling interference TECHNICAL FIELD

The present invention relates to a repeater and repeating method used a wireless communication method, and in particular to a wireless repeater having a built-in RF and IF band width signal synthesizer which is capable of implementing an interference signal removing technology adaptation of a wireless repeater.

BACKGROUND ART

A repeater is disposed between a bast station and a terminal station and is adapted to amplify a low receiving signal level to a better communication quality level, so that it is possible to provide a better communication quality for the interior of a building and an outer area of a city to which a radio wave does not reach well, so that in the above area, an intensity of a radio wave is weak.

As the types of repeaters, there are provided an optical repeater, microwave repeater, variable wave repeater, RF band width signal repeater, etc. The interference removing repeater includes a receiving antenna which is capable of receiving a low level original signal(transmission signal from a base station or a terminal) received from a base station or terminal and a high level interference signal fed from a transmission antenna of a repeater itself, an interference signal removing unit capable of removing an interference signal from the received signals, an amplifier which is capable of amplifying a lower level original signal, a transmission antenna capable of transmitting the same and a circuit block which is provided in addition to the above construction.

The interference removing unit is adapted to protect an original signal from the received signal and to remove an interference signal and has various interference removing construction and performance based on its method and received signal characteristic.

However, the conventional interference removing method is directed to removing an interference by adapting an antenna channel-based receiving signal received from an antenna. In addition, the size and phase of each channel-based signal is largely different based on a radio wave environment and installation condition, a removing ratio of an interference signal is low, and an original signal may be removed in part based on the conventional interference removing method.

DISCLOSURE OF INVENTION

Accordingly, it is an object of the present invention to provide an interference removing wireless repeater having a built-in RF and IF band width signal synthesizer which overcomes the problems encountered in the conventional art.

It is another object of the present invention to provide an interference removing wireless repeater having a built-in RF and IF band width signal synthesizer which is capable of maximizing an interference signal removing ability by enhancing an interference removing efficiency and interference removing band width in such a manner that the differences of a phase and size of a channel-based received signal in the case that the phase and size of a channel-based received signal received to each channel are different by providing a RF and IF band width signal combining unit in a repeater.

In order to achieve the above objects, there is provided a RF and IF band width signal synthesizer formed of an input transmission unit, transmission unit and engaging unit in an interference removing circuit of a conventional repeater. When implementing a RF and IF band width signal synthesizer, the same device as a wireless repeater is needed in a backward link in such a manner that a radio wave is received from a base station and is amplified to a desired signal, and a weak signal of a forward link which outputs a signal to a negative area which will be serviced, is received and amplified to a desired signal for thereby transferring the signal to a base station.

However, in the present invention, since the backward link has the same operational principle as the forward link, only the operational principle of the forward link will be described. The implementation method and construction and effects of the RF and IF band width signal synthesizer for an interference removing technology adaptation of a wireless repeater of the present invention will be described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become better understood with reference to the accompanying drawings which are given only by way of illustration and thus are not limitative of the present invention, wherein; Figure 1 is a view illustrating the construction of a RF and IF band width signal synthesizer for an interference signal removing technology adaptation in a wireless repeater according to the present invention;

Figure 2 is a view illustrating a construction that the RF and IF band width synthesizer of Figure 1 is formed of a N-number of dividers and combining units according to the present invention;

Figure 3 is a view illustrating a detailed example of Figure 2 according to the present invention; and

Figure 4 is a view illustrating a construction with respect to an embodiment that a RF and IF band width signal synthesizer is adapted to an interference removing wireless repeater according to the present invention according to the present invention.

** Descriptions of reference numerals for the major elements of the drawings ** 100: receiving terminal unit 110: receiving antenna 120: N-stage combining unit 130: RF signal bandwidth filter

140: low noise amplifier 200: synthesizer

221 : signal input unit 222: transmission unit, transmission combing unit(when N-number of signals are inputted)

223: combining unit 224, 225: divider

226, 227, 228: equivalent phase transmission unit 229: reverse phase transmission unit 230, 231 : combiner

210: frequency down modulator

220: RF or IF band width signal combining unit

330: frequency up modulator 300: interference removing unit

310: phase and size compensation unit 320: interference removing means

BEST MODE FOR CARRYING OUT THE INVENTION

Figure 1 is a view illustrating the construction of a RF band width signal combining unit for implementing an adaptation of an interference signal removing technology in a wireless repeater according to the present invention.

As shown in Figure 1 , a RF and IF band width signal synthesizer includes a signal input unit 221 formed of dividers 224 and 225, a transmission unit 222 for transmitting a RF and IF band width signal, and a combining unit 223 formed of combiners 230 and 231 capable of combining RF and IF band width signals transmitted.

The signal inputted into the signal input unit 221 includes an interference signal generated from an original signal and surrounding environment. At this time, the interference signal is formed of signals which are fed back as an input signal when the signal is amplified through the repeater, so that the interference signal is a high level signal compared to an original signal.

The original signal and interference signal inputted into the signal input unit 221 are divided into two or more than two equivalent signals by the dividers 224 and 225 which divide are determined based on the output ports of the divider. Figure 1 illustrates an example that the signals are divided into two ports.

The transmission unit 222 is formed of equivalent phase transmission units 226, 227 and 228 capable of directly transferring signals, and a reverse phase transmission unit 229 which is capable of changing the phase using a phase shifter or delay line and then transferring the same.

The signals divided by the divider 224 connected at an end of the signal input unit 221 maintain the phase characteristics of the original signal and interference signal and are transferred to the combining unit 223 through the equivalent phase transmission units 226 and 227, and one signal among the signals divided by the divider 225 connected at the other end of the signal input unit maintain a phase characteristic and is transferred to the combining unit(228), and the remaining signal is transferred to the combining unit 223 through the reverse phase transmission unit 229 which changes the phase by the phase shifter or delay line for thereby implementing a reverse phase with respect to the phase of the original signal.

The combining unit 223 combines the signals inputted from the equivalent phase transmission units 226, 227, and 228 and the reverse phase transmission unit 229 using two combiners 230 and 231 , and the combiner 230 connected at an end of the combining unit 223 does not change the phase characteristic in the different dividers 224 and 225 in the transmission unit, but combine two signals transmitted through the equivalent phase transmission units 226 and 228. The combiner 231 of the other end of the combining unit 223 does not change the phase characteristic, but combines the signal transmitted to the equivalent phase transmission unit 227 and the signals 229 which is transmitted through the reverse phase transmission unit 229 and has a phase reverse to the original signal.

As a result, the combiner 230 connected at an end of the combining unit 223 does not change the phase of the signal, but combines two signals transmitted to the equivalent phase transmission units 226 and 228, so that the sizes of a high level interference signal component and a low level origθinal signal component are all increased. In the combiner 231 connected at the other end of the combining unit 223, since the signals transferred through the equivalent phase transmission unit 227 and the reverse phase transmission unit 229 have the phase reverse with respect to the original signals, the interference having an interference difference is increased, and a low level original signal having no phase difference is removed by the combiner 231 in the receiving antenna.

The above operation is implemented based on the following operation. Namely, the equivalent phase changes are performed with respect to all the original signal and interference signal when passing through the reverse phase transmission unit 229. In the case of the interference signal, since the different phase signals are maldistributed, the signal is not in the reverse phase state with respect to the interference signal inputted through the transmission unit 227.

Therefore, in one path, the interference signal and the original signal are simply combined, but in the other paths, the original signal is removed. Therefore, in the interference removing repeater, the size and phase of the signal are compensated based on a high level interference signal among the receiving signals. When the interference signal is removed based on the combining operation of the reverse phase signal, it is possible to prevent a problem that a part of the original signal is removed when the interference signal is removed. Figure 2 is a view illustrating a construction that the RF and IF band width signal combining unit of Figure 1 are formed of N-number of dividers and combining units.

As shown in Figure 2, the RF and IF band width combining structure includes a signal input unit 221 formed of a N-number of dividers, a transmission combining unit 222 which transmits a RF and IF band width signal and processes a signal based on a combining unit based on a certain characteristic, and a combining unit 223 which combines the transmitted RF and IF band width signals based on a combining unit.

The signal input unit 221 divides the N-number of signals inputted through the input unit using the n-number of the dividers. The number of signals divided is determined based on the construction of the transmission combining unit for maintaining a certain signal characteristic of the combining unit.

The transmission combining unit 222 includes an equivalent phase transmission unit which does not change the phase, a reverse phase transmission unit which does not change the phase by the phase shifter or delay line, and a combiner. The transmission combining unit may be constructed in such a manner that the signal inputted into the combining unit has a certain uniform characteristic.

The characteristic of the signal inputted into the combining unit 223 represents that in the combiner 230 connected at an end of the combining unit 223 in two combiners in the synthesizer, the N-number of the signals inputted into the input signal unit are received into the combiner 230 through the equivalent phase transmission unit without any change in the phase, and in the combiner 231 connected at the other end of the combiner 223, the original signals which exist in the signals inputted into the combiner 231 based on the constructions of the transmission unit, reverse phase transmission unit and combiner in the combining transmission unit is processed for thereby being removed based on the reverse phase and are inputted into the combiner.

The combining unit 223 is formed of two combiners. The signals inputted based on the input signal characteristic of the synthesizer in the transmission combining unit 222 are combined by the combiner. The sizes of a high level interference signal component and low level original signal component in the N- number of signals inputted into the input transmission unit are increased by a synthesizing operation, and in the combiner 231 connected at the other end of the combining unit 223, since the signals transmitted through the transmission combining unit 222 are in the reverse phase state with respect to the original signals, the interference of the signal having a phase difference is increased, and a low level original signal which does not have a phase difference is removed by the combiner 231.

Figure 3 is a view illustrating the construction of a detailed embodiment of Figure 2.

As shown in Figure 3, the signal input unit may be formed of four dividers, and the transmission combining unit may be formed of eleven transmission units and one reverse phase transmission unit, and the synthesizer may be formed of two combiners. The above construction is provided based on an input signal characteristic of the combining unit 223.

Differently from the construction of Figure 3, the number of the signals divided into the dividers, the number of the combiners needed for the transmission combining units, and the position of the reverse phase transmission unit may be constructed in various forms as long as they maintain a certain characteristic of the input signal of the combining unit 223. Figure 4 is a view illustrating an embodiment that the RF and IF band width synthesizer is adapted to the interference removing wireless repeater.

As shown in Figure 4, the repeater of the wide area band width mobile communication system includes a receiving terminal block 100 formed of an antenna 110, a N-stage combining unit 120, a band width filter 130 in the RF signal, and a low level amplifier 140, a synthesizer 200 formed of a frequency down modulator 210, a RF or IF synthesizer 220, and a frequency up modulator 230, and an interference removing unit 300 formed of a phase compensation unit 310 and an interference removing means 320. In the thusly constituted wireless repeater, the signals received into more than two antenna paths 110 may be directly used based on a propagation environment, and may be combined through the synthesizer 120 of more than two paths, the band width filter 130, the low noise amplifier 140 and the RF and IF band width signal synthesizer 220 according to the present invention. At this time, in the case that the signals processed by the RF and IF band width signal synthesizer 220 are processed in the RF band width, the constructions of the frequency down modulator 210 and the frequency up modulator 230 of Figure 4 may be removed. However, in the case of the process in the IF band width, the frequency up modulator 210 and the frequency down modulator 330 are connected at both ends of the synthesizer 220.

The signals combined by the RF and IF band width signal synthesizer 220 are a synthesized signal with respect to each antenna or channel. There is a different whether an original signal is removed between the output signals of the synthesizer by the reverse phase synthesizing path. Since the low level original signal is relatively low compared to the interference, the phase difference and size based on the frequency of the whole synthesized signals have similar characteristics in the wide area band width.

In the interference removing unit 300, the interference signal is removed from the signals which are processed by the synthesizer and have the similar characteristics over the wide area band width in their phase difference and size. As described above, in the present invention, the phase difference based on the frequency has a uniform difference in each path of the antenna by providing the wireless repeater with a RF and IF band width signal synthesizing technology. Therefore, the interference removing technology which has a channel-based narrow area band width characteristic when the phase difference based on the conventional path-based frequency are different has the wide area band width characteristic.

In addition, in the present invention, it is possible to prevent a decrease in an interference removing effect which occurs when the size and phase of the signals of each channel are very different because it is impossible to estimate based on a propagation environment of the channel-based receiving signal waveform of a receiving antenna. In the present invention, it is possible to maintain similar signals with respect to each antenna path even when there are installation environment changes such as an antenna direction of a wireless repeater and a surrounding environment change, so that it is possible to implement a desired adaptation with respect to various environment changes. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described examples are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. In a wireless repeater using a RF(Radio Frequency) signal, a wireless repeater having a built-in IF band width synthesizer capable of removing an interference signal, comprising: a receiving terminal unit which synthesizes a signal received through an antenna using a N-stage combiner and filters a RF band width signal through a band width filter and amplifies a signal using a low level amplifier; a combining unit which receives a signal processed by the receiving terminal unit and synthesizes a signal through a RF band width signal synthesizer; and an interference removing unit which is formed of a phase compensation means capable of changing a phase of a signal processed in the synthesizing unit and an interference removing means which is capable of removing an interference signal of the processed signal.

2. The repeater of claim 1 , wherein said synthesizing unit includes a frequency down modulator and a frequency up modulator for thereby processing based on a IF band width signal in the synthesizing unit.

3. The repeater of either claim 1 or claim 2, wherein said RF and IF band width synthesizer includes: a signal input unit which is formed of dividers separating an inputted signal into more than two equivalent signals; a transmission unit which is formed of an equivalent phase transmission unit capable of transmitting a RF and IF band width signal without a variation in a phase and a reverse phase transmission unit which is capable of varying a phase of a signal for thereby obtaining a phase reverse to the phase of an original signal; and a combining unit which is adapted to synthesize the transmitted RF and IF band width signal using a combiner.

4. The repeater of claim 3, wherein said RF and IF band width synthesizing unit includes: a signal input unit which is formed of a N-number of dividers capable of separating a N-number of inputted signals into more than 2N-number of equivalent signals; a transmission combining unit which is formed of an equivalent phase transmission unit capable of transmitting a divided signal without a variation of phase, a reverse phase transmission unit capable of varying a phase based on a shifter or delay line, and a combiner capable of combining more than two signals; and a combining unit which is formed of a combiner capable of combining more than four signals transmitted from the transmission combining unit into two signals.

5. The repeater of claim 4, wherein said transmission combining unit includes: a combiner connected at one end of the combining unit which receives a N-number of signals inputted into the input signal unit as an input without varying the phase based on a construction of an equivalent phase transmission unit and combiner in a transmission combining unit which includes an equivalent phase transmission unit capable of transferring in such a manner that two combiners in the combining unit do not provide a variation in a phase, a reverse phase transmission unit capable of transmitting based on a variation in the change, and a combiner capable of combining more than two signals; and a combiner connected at the other end of the combining unit which receives an original signal existing in the signals inputted into the combiner for thereby being removed based on a reverse phase relationship during a signal synthesizing operation in the constructions of an equivalent phase transmission unit, reverse phase transmission unit and combiner in the transmission combining unit formed of an equivalent phase capable of transmitting without a variation in a phase, a reverse phase transmission unit capable of transferring by providing a phase with a variation and a combiner capable of combining more than two signals.

6. The repeater of claim 5, wherein each divider of the signal input unit is capable of dividing one signal into more than two signals, and the combiner in the transmission combining unit and combining unit is capable of combine more than two signals into one signal.