KR100746577B1 - Interference Cancellation Repeater - Google Patents

Abstract

The present invention relates to an interference cancellation wireless repeater. The interference canceling wireless repeater is intended to remove an interference signal from which a radio signal radiated from a transmitting antenna is re-received to a receiving antenna after passing through several paths, thereby causing oscillation or other degradation of signal quality. The interference canceling wireless repeater according to the present invention uses an adaptive filter to efficiently remove the interference signals from which the transmission signal is re-received by the reception antenna. In addition, the interference cancellation wireless repeater according to the present invention is adapted by processing the signal by dividing the entire frequency band of the received signal by several bands or channels when the received signal is a broadband or multi-channel radio signal. It is easy to implement the type filter and improve the interference cancellation performance.

Wireless Repeater, Adaptive Filter, Interference Cancellation

Description

Interference Cancellation Repeater {Interference Cancellation Repeater}

1 is a block diagram schematically illustrating a conventional wireless relay apparatus using the same transmission / reception frequency.

FIG. 2 is a block diagram schematically showing the overall configuration of an interference canceling wireless repeater according to a first embodiment of the present invention, and FIG. 3 is a schematic diagram showing the configuration of an interference canceling signal processor of the interference canceling wireless repeater of FIG. 4 is a block diagram schematically illustrating a configuration of an interference controller of the interference cancellation signal processor of FIG. 3.

FIG. 5 is a spectral diagram of an input signal and an output signal of a digital down converter, and FIG. 6 is a spectral diagram of an input signal and an output signal of a digital up converter.

7 is a block diagram schematically showing the overall configuration of an interference canceling wireless repeater according to a third embodiment of the present invention.

8 is a block diagram schematically showing the overall configuration of an interference canceling type wireless repeater according to a fourth embodiment of the present invention, and FIG. 9 is an interference cancellation signal of an interference canceling type wireless repeater according to a fourth embodiment of the present invention. It is a block diagram which shows the structure of a process part schematically.

FIG. 10 is a block diagram schematically illustrating a configuration of an interference cancellation signal processing unit of an interference cancellation type wireless repeater according to a fifth embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

20: interference canceling wireless repeater

202: receiver

210: first downlink frequency converter

220: interference cancellation signal processing unit

230: uplink frequency converter

240: amplifier

250: second downlink frequency converter

260: gain control unit

300: first A / D conversion unit

310: first channel received signal digital down converter

320: first channel reference signal digital down converter

330: first channel interference controller

340: first channel digital up-converter

350: combiner

360: D / A converter

400: adaptive filter unit

402 digital filter

404: filter coefficient adjustment unit

410: adder

The present invention relates to an interference canceling wireless repeater used in a wireless communication system. More particularly, an adaptive filter is applied to remove an interference signal from a received signal, or the received wireless signal is a broadband or multiplexed channel. If present, the present invention relates to an interference canceling wireless repeater that divides a signal into several smaller bands or channels and then removes an interference signal by applying an adaptive filter to each signal.

A repeater is located between a base station and a terminal station to amplify a low received signal level to a good call quality level so as to provide good call quality, such as an area inside or outside a building where the radio wave is not reached and the radio wave strength is weak. Says device for. Types of repeaters include optical repeaters, microwave repeaters, variable wave repeaters, and radio (RF) repeaters.

Among the repeaters described above, the wireless repeater is intended to reduce the radio shadow area and improve the call quality that occurs during the operation of the wireless communication system, and refers to a repeater in which the frequency of the received signal and the frequency of the transmitted signal are operated in the same manner.

The general wireless communication relay device shown in FIG. 1 is a relay device 10 using the same transmission / reception frequency, and receives a radio wave from a base station, amplifies it, and then receives a radio wave from a forward link and a service area that radiate it to a service area. It has a reverse link that is amplified and transmitted to a base station. Since both the forward link and the reverse link have the same structure, only the operation of the forward link will be described here.

First, when a high frequency signal to be relayed is received through the reception antenna 100 and then input to the reception filter unit 110, the reception filter unit 110 performs band pass filtering of the reception signal and then amplifies the filtered reception signal. Transfer to section 120. Subsequently, the amplifier 120 amplifies the filtered received signal and transmits the amplified signal to the service area through the transmit antenna 130. However, as shown in FIG. 1, the wireless repeater 10 having only a function of simply amplifying and transmitting a received signal does not have good isolation between transmitting and receiving antennas, and thus the signal transmitted from the transmitting antenna 130 is received again. There is a problem that the repeater is oscillated by being fed back to the antenna 100, amplified together with the original signal, and sent back to the transmitting antenna. This oscillation causes more problems in large wireless repeaters with strong transmission signals from the transmitting antenna.

Therefore, in order to sufficiently remove the feedback signal to the receiving antenna causing the oscillation as described above, in general, the wireless repeater separates the transmitting antenna and the receiving antenna and installs the remote to increase the separation between the transmitting and receiving antennas, and has excellent directionality. I am using a directional antenna. However, since the transmitting and receiving antennas should be installed far away so that the separation of the transmitting and receiving antennas is larger than the gain of the repeater, the installation cost increases. The gain of the repeating apparatus should be reduced to reduce the feedback of the transmission signal. There is a restriction.

In order to solve this problem, conventionally, in order to improve the correlation spacing of the relay base station, the shielding obstacles of the transmitting and receiving aerials are installed or the space separation is performed, the frequency conversion relay and the phase signal processing method are used in the smart antenna technology. There is a problem in that it requires installation trouble and an expensive signal processing device.

In addition, recently, various methods for removing the above-described interference signal from a received signal by applying digital signal processing technology have been proposed. Most of the proposed schemes estimate the reflected signals reflected from the antenna and the surrounding obstacles, and cancel them from the received signals. In reality, accurate estimation of the reflected signals is difficult and the time required for estimation is long. There are problems that it is almost impossible to eliminate the interference in real time due to environmental changes. Therefore, conventionally proposed schemes are not suitable for practical use in terms of performance, and as a result, their use in actual field environments is very limited.

An object of the present invention for solving the above problems is to provide an interference cancellation type wireless repeater that applies an adaptive filter to efficiently remove the interference signal received from the transmitting antenna back to the receiving antenna.

Another object of the present invention is to divide the received signal into several frequency bands or to each channel when the received wireless signal is a broadband signal or a multi-channel signal, and adaptive filter on the divided signals. By removing the interference signal by applying a, it is possible to efficiently remove interference signals having a long delay time, and to provide an interference cancellation wireless repeater that can efficiently implement an adaptive filter having a fast interference cancellation performance.

A feature of the present invention for achieving the above technical problem relates to an interference canceling wireless repeater for removing an interference signal from a received signal, the interference canceling wireless repeater

A receiver which gain-adjusts and transmits a received signal received from a receiving antenna;

A downlink frequency converting unit converting the received signal transmitted from the receiving unit into a signal of an intermediate frequency band and outputting the converted signal;

The received signal transmitted from the downlink frequency converter is divided into at least one channel, an interference signal is removed from the divided received signals for each channel using an adaptive filter, and the divided received signals for each channel are received as one signal. An interference cancellation signal processor for transmitting the combined signal to

An uplink frequency converter for converting a signal transmitted from the interference cancellation signal processor into a signal of an original frequency band that can be output;

An amplifier for amplifying the signal transmitted from the uplink frequency converter;

A transmission antenna for transmitting a signal transmitted from the amplifier,

The interference cancellation signal processor

An A / D converter for converting an analog signal into a digital signal;

At least one digital down converter that receives the signal transmitted from the A / D converter, converts the signal into a baseband signal, divides each channel, and converts the received signal for the corresponding channel into a preset sampling rate. Wow,

At least one interference controller for outputting a corresponding channel signal from which the interference signal is removed from the received signal of the corresponding channel received from the received signal digital down converter using a predetermined reference signal;

At least one digital upconverter for increasing the sampling rate of the corresponding channel signal transmitted from the interference control unit and converting the sampled signal into a signal of an intermediate frequency band;

A combiner for combining the signals of all channels output from the at least one digital upconverter into one signal, and

And a D / A converter converting the signal output from the combiner into an analog signal,

The interference controller

An adaptive filter unit which receives a reference signal for removing the interference signal, estimates the interference signal from the reference signal by applying an adaptive filter algorithm, and outputs an interference estimation signal;

An adder that receives a received signal including an interference signal to a non-inverting terminal, receives an interference estimation signal output from the adaptive filter unit to an inverting terminal, and outputs an error signal from which the interference estimation signal is removed from the received signal. Lose,

The adaptive filter unit

A filter coefficient adjusting unit which receives the reference signal and the error signal output from the adder and outputs filter coefficients adjusted in real time for every signal sample by an adaptive filter algorithm;

And a digital filter that receives the reference signal and filter coefficients output from the filter coefficient adjusting unit and outputs an interference estimation signal generated by digitally filtering the reference signal.

Preferably, the interference cancellation type wireless repeater having the above-mentioned characteristics uses the output signal of the interference control unit as a reference signal input to the interference control unit of the interference cancellation signal processor.

According to another aspect of the present invention, an interference cancellation type wireless repeater further includes at least one or more reference signal digital down converters in the interference cancellation type wireless repeater described above.

The reference signal digital down converter receives an output signal of a digital up converter of a corresponding channel, converts the input signal into a baseband signal for each channel, and converts the sampling rate into a preset sampling rate and outputs the converted sampling rate. ,

The output signal of the reference signal digital down converter is used as a reference signal input to the interference controller of the interference cancellation signal processor.

An interference canceling wireless repeater according to another aspect of the present invention,

A receiver which gain-adjusts and transmits a received signal received from a receiving antenna;

A downlink frequency converting unit converting the received signal transmitted from the receiving unit into a signal of an intermediate frequency band and outputting the converted signal;

A predetermined reference signal and the received signal are input, and the received signals transmitted from the downlink frequency converter are divided for each channel, the interference estimation signal estimated from the reference signal is extracted using an adaptive filter, and the division is performed. An interference cancellation signal processor for removing the interference estimation signal of the corresponding channel from the received signals for each channel, combining the received signals for each channel into one signal, and transmitting the combined signal;

An uplink frequency converter for converting a signal transmitted from the interference cancellation signal processor into a signal of an original frequency band that can be output;

An amplifier for amplifying the signal transmitted from the uplink frequency converter;

A transmission antenna for transmitting a signal transmitted from the amplifier,

The interference cancellation signal processor

A first A / D converter for converting an analog received signal into a digital signal;

A second A / D converter for converting an analog reference signal into a digital signal;

At least one digital receiving signal which receives the signal transmitted from the first A / D converter, converts into a baseband signal, divides each channel, and converts the received signal for the corresponding channel to a preset sampling rate. With a down converter,

At least one digital signal downlink receiving the signal transmitted from the second A / D converter, converting the signal into a baseband signal, dividing the signal into channels, and converting the reference signal for the corresponding channel to a preset sampling rate. With a converter,

Generating an interference estimation signal using a reference signal of a corresponding channel input from the reference signal digital downconverter, and outputting a corresponding channel signal from which the interference estimation signal is removed from a received signal of the corresponding channel received from the received signal digital downconverter At least one interference control unit,

At least one digital upconverter for increasing the sampling rate of the corresponding channel signal transmitted from the interference control unit and converting the sampled signal into a signal of an intermediate frequency band;

A combiner for combining the signals of all channels output from the at least one digital upconverter into one signal, and

And a D / A converter converting the signal output from the combiner into an analog signal.

Preferably, the interference cancellation type wireless repeater having the above-described characteristics uses the output signal of the interference cancellation signal processor as a reference signal input to the interference cancellation signal processor.

On the other hand, the interference cancellation wireless repeater according to another aspect of the present invention, in the above-described interference cancellation wireless repeater uses the output signal of the uplink frequency converter as a reference signal input to the interference cancellation signal processor,

The interference cancellation type wireless repeater further includes an additional downlink frequency converter between the uplink frequency converter and the interference cancellation signal processor.

The additional downlink frequency converter converts an output signal of the uplink frequency converter into a signal of an intermediate frequency band and transmits the signal to the interference cancellation signal processor.

The interference canceling wireless repeater according to another aspect of the present invention uses the output signal of the amplifying unit as the reference signal input to the interference canceling signal processing unit in the interference canceling wireless repeater described above,

The interference cancellation type wireless repeater further includes an additional downlink frequency converter between the amplifier and the interference cancellation signal processor.

The additional downlink frequency converter converts the output signal of the amplifier into a signal of an intermediate frequency band and transmits the signal to the interference cancellation signal processor.

Hereinafter, embodiments of the interference cancellation type wireless repeater having the above-described characteristics will be described in detail.

First embodiment

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the interference cancellation type wireless repeater according to the first embodiment of the present invention.

FIG. 2 is a block diagram schematically illustrating an overall configuration of an interference cancellation type wireless repeater 20 according to a first exemplary embodiment of the present invention, and FIG. 3 illustrates an internal configuration of the interference cancellation signal processor 220 of FIG. 2. 4 is a schematic block diagram, and FIG. 4 is a block diagram schematically illustrating an internal configuration of the first channel interference controller 330 of FIG. 3.

First, referring to FIG. 2, the interference canceling wireless repeater 20 according to the first embodiment of the present invention includes a receiving antenna 200, a transmitting antenna 242, a receiving unit 202, and a first downlink frequency converting unit ( Frequency Down Converter (210), Interference Cancellation Signal Processing Unit (220), Frequency Up Converter (230), Amplifier (240), Second Down Frequency Converter (250), and Gain Adjuster (260). It is provided. Hereinafter, each component of the aforementioned interference cancellation type wireless repeater 20 will be described in detail.

The receiver 202 receives the radio signal from the receiving antenna 200, adjusts the gain to an appropriate level, and transmits it to the first downlink frequency converter 210.

The first downlink frequency converter 210 converts a radio frequency signal received from the receiver 202 into an intermediate frequency IF and transmits the radio frequency signal to the interference cancellation signal processor 220. In this case, the signal transmitted from the first downlink frequency converter 210 to the interference cancellation signal processor 220 is transmitted from the interference signal and the original signal source that the output signal of the repeater transmitted from the transmitting antenna is received back to the receiving antenna. A signal summed together, which is a signal before interference is removed.

The second downlink frequency converter 250 feeds back the signal output from the amplifier 240, receives the input signal, converts the signal to an intermediate frequency, and transmits the signal to the interference cancellation signal processor 220. At this time, the signal input to the second downlink frequency converter 250 is a signal corresponding to the signal source of the interference signal component that the output signal of the repeater is received back to the receiving antenna, the original radio in the interference cancellation signal processor 220 It becomes a reference signal for removing the interference signal included in the signal.

The gain controller 260 adjusts the gain of the signal output from the amplifier 240 to an appropriate level and transmits the gain to the second downlink frequency converter 250.

The interference cancellation signal processor 220 removes an interference signal from a wireless signal received from the first downlink frequency converter by using a reference signal received from the second downlink frequency converter 250 to perform an uplink frequency converter ( 230).

The uplink frequency converter 230 converts the intermediate frequency signal transmitted from the interference cancellation signal processor 220 into a signal of the original high frequency band and transmits the signal to the amplifier 240, and the amplifier 240 receives the received signal. The signal is amplified and transmitted to the outside through the transmission antenna 242.

Hereinafter, the configuration and operation of the interference cancellation signal processor 220 will be described in detail with reference to FIGS. 3 and 4.

Referring to FIG. 3, the interference cancellation signal processor 220 may include a first A / D converter 300, a second A / D converter 302, and at least one received signal digital down converter. Hereafter referred to as 'DDC' 310, 312, 314, at least one reference signal digital down converter (320, 322, 324), at least one interference canceller (330, 332, 334), at least one digital up converter (Digital Up Converter: hereinafter referred to as 'DUC'; 340, 342, 344), an adder 350, and a D / A converter 360. In the interference cancellation signal processor 220 having the above-described configuration, a received signal and a reference signal are respectively input from the first downlink frequency converter and the second downlink frequency converter, and the interference signal is removed from the received signal using the reference signal. Thereafter, the received signal from which the interference signal is removed is transmitted to the uplink frequency converter. Hereinafter, a process of removing the interference signal from the received signal by the interference cancellation signal processor 220 using the reference signal will be described.

The first A / D converter 300 converts an analog received signal into a digital signal and then transmits the received signal to at least one received signal DDC, and the second A / D converter 302 transmits the analog reference signal. After converting to a digital signal and transmitted to at least one reference signal DDC.

Received Signal DDC converts a wideband received signal or a mixed signal of multiple channels (multi-channel) into a baseband signal, and then separates a signal of a specific band or a specific channel using a digital filter and separates it. The sample rate of the received signal is converted to the lowest possible sampling rate (e.g., Nyquist rate) for the single band or channel. Therefore, the received signal DDC of the interference canceling wireless repeater according to the present invention includes the number of bands or channels constituting the received signal, and includes a first channel received signal DDC 310, a second channel received signal DDC 310, … The n-th channel received signal DDC 314 is performed. The first channel reception signal DDC 310 transmits a digital first channel reception signal to the first channel interference control unit 330, and the second channel reception signal DDC 312 transmits a digital second channel reception signal. The second channel interference controller 332 is transmitted, and the n-th channel received signal DDC 314 transmits the n-th channel received signal in a digital form to the n-th interference controller 334.

FIG. 5 is a spectrum diagram illustrating the operation of the DDC module. FIG. 5A is a spectral diagram of an input signal of a DDC module, and FIG. 5B is a spectrum of an output signal of a DDC module. It is also. In FIG. 5, f _s1 is a sampling rate of an input signal to a DDC, and f _s2 is a sampling rate of an output signal to a DDC. Referring to (a) and (b) of FIG. 5, a multiplex channel signal mixed with multiple channels is input to a DDC, and a signal of an i-th channel, which is a specific channel, is separated and a sampling rate is reduced from f _s1 to f _s2 . You can see that it is printed as

Meanwhile, the reference signal DDC converts a received signal mixed with several channels into a baseband signal, separates a signal of a specific channel, and converts and outputs a sampling rate of the separated signal equal to the sampling rate of the received signal DDC. . Therefore, the reference signal DDC of the interference cancellation type wireless repeater according to the present invention is provided with the same number as the received signal DDC, and includes the first channel reference signal DDC 320, the second channel reference signal DDC 322,. The n-th channel reference signal DDC 324 is performed. Since the reference signal DDC operates in the same manner as the reception signal DDC described above, a detailed description thereof will be omitted. The first channel reference signal DDC 320 transmits a digital first channel reference signal to the first channel interference controller 330, and the second channel reference signal DDC 322 transmits a digital second channel received signal. The n-th channel reference signal DDC 324 transmits the n-th channel reference signal in a digital form to the n-th interference control unit 334.

The interference controller applies an adaptive filter to remove the interference estimation signal of each channel estimated from the reference signal from the received signal of the corresponding channel, and outputs the first and second channel interference controllers 330 and the second channel. Interference control unit 332,... , The n-th channel interference control unit 334. 4 is a block diagram schematically illustrating the configuration of the first channel interference controller 330. Referring to FIG. 4, the first channel interference controller 330 includes an adaptive filter unit 400 and an adder 410, and the adaptive filter unit 400 includes a digital filter 402 and a filter coefficient adjusting unit ( 404).

The digital filter 402 is implemented in the form of a finite impulse response filter (hereinafter referred to as a 'FIR filter'), and includes a first channel reference signal and a filter coefficient adjusting unit output from the first channel reference signal DDC ( The filter coefficient output from 404 is input, and the output signal is input to the inverting terminal of the adder 410. The output signal of the digital filter 402 is an interference estimation signal that estimates a feedback interference signal in which the output signal of the corresponding channel of the wireless repeater is received back to the receiving antenna through various paths.

The filter coefficient adjusting unit 404 receives the reference signal of the corresponding channel and the error signal e output from the adder 410, and filters the filter coefficients adjusted in real time by an adaptive filter algorithm. ) The filter coefficient is a numerical value adjusted in real time to minimize the error component by the adaptive filter algorithm, and the convergence speed of the adaptive filter algorithm is faster as the number of tabs is smaller. The number of the FIR filter tap (N _tab) is determined by the removable signal delay (t _delay) and sampling rate (f _sample) of the signal. As a result, the interference cancellation time of the adaptive filter unit is faster as the removable signal delay time is shorter and the sampling rate is lower. The adaptive filter algorithm for adjusting the coefficients of the FIR filter has to operate at every sample of the signal. Therefore, when the time interval between samples is short, the processing time of the adaptive filter algorithm is limited, making it difficult to implement. This will occur. In order to solve this problem, the interference canceling wireless repeater according to the present invention uses an adaptive filter to reduce the sampling rate of the signal by dividing by each channel in order to solve this problem. Enable implementation

Meanwhile, the first channel reception signal output from the first channel reception signal DDC is input to the non-inverting terminal of the adder 410, and the interference estimation signal, which is an output signal of the adaptive filter, is input to the inverting terminal of the adder 410. The adder 410 outputs an error signal e from which the interference estimation signal is removed from the first channel received signal. The error signal e output from the adder is input to the filter coefficient adjusting unit 404 and used as a signal for adjusting the coefficients of each tap of the digital filter in real time by an adaptive filter algorithm, and the filter coefficient adjusting unit 404 동작 operates to change the coefficients of the taps of the digital filter in a direction that minimizes the power of the aforementioned error signal e.

Accordingly, the error signal output from the adder is a signal obtained by removing the interference estimation signal from the first channel reception signal, and becomes a first channel signal that is an output signal of the first interference controller 330. Through this process, the first channel signal output from the adder is transmitted to the first channel digital up converter (hereinafter referred to as 'DUC': 340).

The digital upconverter (DUC) increases the sampling rate of the signal processed in the baseband and then converts the signal into a carrier frequency on an intermediate frequency. The interference canceling wireless repeater according to the present invention converts a received signal for each channel. The first channel DUC 340, the second channel DUC 342,... N-channel DUC 344. 6 (a) and 6 (b) are spectral diagrams of the input signal and the output signal of the DUC, respectively. Here, f _s2 denotes a sampling rate of the input signal of the DUC, and f _s1 denotes a sampling rate of the output signal of the DUC. The first channel DUC 340 receives a first channel signal, which is an output signal of the first channel interference controller 330, and has a sampling rate increased to convert the first channel signal into a signal of a carrier frequency on an intermediate frequency. Is output. The first channel DUC, the second channel DUC,... ..., First channel signal, second channel signal output from n-th channel DUC,. The n-th channel signal is input to the combiner 350, combined into one signal, and then converted into an analog signal by the D / A converter 360 and output.

The interference canceling wireless repeater according to the present invention having the above-described configuration reduces the frequency bandwidth by dividing the received signal into channels, thereby reducing the sampling rate by the DDC, and thus, for the same removable interference delay time. The number of taps in the adaptive filter is reduced. Accordingly, the convergence speed of the adaptive filter algorithm is shortened, which not only reduces the interference cancellation time but also increases the time interval between each signal sample, thereby facilitating the implementation of the algorithm. In addition, the interference canceling wireless repeater according to the present invention can not only control on-off for each channel, but also gain can be adjusted and power can be measured for each channel, Various additional functions can be implemented.

Second embodiment

In the interference canceling type wireless repeater according to the second exemplary embodiment of the present invention, a signal extracted from the point B of FIG. 2 is gain-controlled by using a signal extracted from the point B of FIG. 2 as a reference signal input to the interference cancellation signal processor. The unit is input to the second downlink frequency converter, and the signal input to the second downlink frequency converter is converted into an intermediate frequency signal and transmitted to the interference cancellation signal processor.

Third embodiment

Hereinafter, the configuration and operation of the interference cancellation type wireless repeater according to the third embodiment of the present invention will be described in detail with reference to FIG. 7. Referring to FIG. 7, the interference canceling wireless repeater 70 according to the third embodiment may include a receiver 702, a downlink frequency converter 710, an interference canceling signal processor 720, an uplink frequency converter 730, An amplifier 740, and a transmitting antenna and a receiving antenna. The interference canceling type wireless repeater 70 according to the third exemplary embodiment is used after adjusting a signal output from the interference cancellation signal processor 720 as a reference signal of the interference cancellation signal processor 720. Since the configuration and operation of other components of the interference canceling type wireless repeater 70 according to the third embodiment are the same as those of the first embodiment, overlapping descriptions are omitted.

Fourth embodiment

Hereinafter, the configuration and operation of the interference cancellation type wireless repeater 80 according to the fourth embodiment of the present invention will be described in detail with reference to FIGS. 8 and 9. 8 is a block diagram schematically showing the overall configuration of an interference canceling type wireless repeater 80 according to a fourth embodiment of the present invention, and FIG. 9 is an interference canceling type wireless repeater according to a fourth embodiment of the present invention. 80 is a block diagram schematically illustrating an internal configuration of the interference cancellation signal processor 820.

Referring to FIG. 8, the interference canceling wireless repeater 80 according to the fourth embodiment of the present invention includes a reception antenna 800, a receiver 802, a downlink frequency converter 810, and an interference cancellation signal processor 820. And an uplink frequency converter 830, an amplifier 840, and a transmit antenna 842, and the internal configuration and operation of other components except for the interference cancellation signal processor 820 are the same as those of the first embodiment. Duplicate explanations are omitted.

9, the interference canceling signal processor 820 of the interference canceling wireless repeater 80 according to the fourth embodiment of the present invention is an A / D converter 900, first, 2,. , n channel received signals DDC (910, 912, 914), first, 2,... , n channel reference signals DDC (920, 922, 924), first, second,... , n channel interference controllers 930, 932, 934, first, 2,... and an n-channel DUC 940, 942, 944, an adder 950, and a D / A converter 960. The interference canceling signal processor 820 of the interference canceling wireless repeater 80 according to the present embodiment is a reference signal for interference cancellation. , output signals of the n-channel DUCs 940, 942, 944 are used. Therefore, unlike the interference cancellation type wireless repeaters of the first to third embodiments described above, the reference signal of the interference control unit 930 of the interference cancellation type wireless repeater 80 according to the fourth embodiment is a separate A / D conversion. There is no need to go through the process.

Fifth Embodiment

Hereinafter, the configuration and operation of the interference cancellation type wireless repeater according to the fifth embodiment of the present invention will be described. The overall configuration of the interference canceling wireless repeater according to the fifth embodiment of the present invention is the same as that of the interference canceling wireless repeater of the fourth embodiment, and only the configuration of the interference canceling signal processing unit is different. FIG. 10 is a block diagram schematically illustrating a configuration of an interference cancellation signal processing unit of an interference cancellation type wireless repeater according to a fifth embodiment of the present invention. Referring to FIG. 10, the interference cancellation signal processor according to the present exemplary embodiment may include the A / D converter 1000, the first, second, and n-channel received signals DDCs 1010, 1012,..., 1014, first, second, and the like. … , n channel interference controllers 1030, 1032, ..., 1034, first, 2,... , n-channel DUCs 1040, 1042,..., 1044, an adder 1050, and a D / A converter 1060. 1, 2,... In the interference cancellation signal processing unit according to the present embodiment. , the n channel interference controllers 1030, 1032, and 1034 are reference signals for canceling the interference signal. , the output signal of the n-channel interference control unit is used as it is.

Although the present invention has been described above with reference to preferred embodiments thereof, this is merely an example and is not intended to limit the present invention, and those skilled in the art do not depart from the essential characteristics of the present invention. It will be appreciated that various modifications and applications which are not illustrated above in the scope are possible. For example, in the embodiment of the present invention, the detection point of the reference signal for removing the interference signal from the received signal may be variously modified to improve the performance of the wireless repeater and the performance of the adaptive filter. And differences relating to such modifications and applications should be construed as being included in the scope of the invention defined in the appended claims.

Unlike the conventional repeater that tracks each feedback signal for each path, the repeater according to the present invention can not only simultaneously remove the entire feedback interference signal by using an adaptive filter algorithm using the transmission signal as a reference signal but also in real time. Removal is also possible.

According to the present invention, it is possible to reduce the interference cancellation time by dividing the received signal into several bands or channels. Here, the interference cancellation time refers to the time taken to remove the interference signal of the system and reach a stable signal quality when the external channel changes and the state of the interference signal changes.

 In addition, according to the present invention, it is easier to implement the adaptive filter of the interference canceling unit by dividing and processing the received signal for each channel.

In addition, according to the present invention, by receiving and processing a received signal composed of multiplexed channels for each channel, it is possible to control the on / off of the signal for each channel and gain adjustment is possible.

Claims (11)

A receiver which adjusts and transmits a received signal received from the receiving antenna; A downlink frequency converting unit converting the received signal transmitted from the receiving unit into a signal of an intermediate frequency band and outputting the converted signal; The received signals transmitted from the downlink frequency converter are divided into at least one or more bands or at least one or more channels, and after the interference signal is removed from the divided channel signals by using an adaptive filter, the respective interference signals are removed. An interference cancellation signal processor for combining and transmitting the signals into one signal; An uplink frequency converter for converting a signal transmitted from the interference cancellation signal processor into a signal of an original frequency band that can be output; An amplifier for amplifying the signal transmitted from the uplink frequency converter; And A transmission antenna for transmitting a signal transmitted from the amplifier; And an adaptive filter of the interference canceling signal processor, wherein the adaptive filter removes and outputs an interference signal from a received signal using each channel signal from which the interference signal is removed in the interference cancellation signal processor as a reference signal. Repeater. The method of claim 1, wherein the interference cancellation signal processing unit An A / D converter for converting an analog signal into a digital signal; At least one digital down converter that receives the signal transmitted from the A / D converter, converts the signal into a baseband signal, divides each channel, and converts the received signal for the corresponding channel to a preset sampling rate. ; At least one interference controller for outputting a corresponding channel signal from which the interference signal is removed from the received signal of the corresponding channel received from the received signal digital down converter using a predetermined reference signal; At least one digital up-converter for increasing the sampling rate of the corresponding channel signal transmitted from the interference control unit and converting the sample signal into a signal of an intermediate frequency band; A combiner for combining signals of all channels output from the at least one digital upconverter into one signal; And D / A converter for converting the signal output from the combiner into an analog signal Interference-cancelling wireless repeater comprising a. The apparatus of claim 2, wherein the interference controller includes an adaptive filter unit and an adder. The adaptive filter unit, A filter coefficient adjusting unit which receives a reference signal for removing interference signals and an error signal output from the adder, and outputs filter coefficients by applying an adaptive filter algorithm; And A digital filter configured to receive the reference signal and filter coefficients output from the filter coefficient adjusting unit, estimate an interference signal from the reference signal, and output an interference estimation signal, The adder receives a received signal including an interference signal through a non-inverting terminal, receives an interference estimation signal output from the digital filter through an inverting terminal, and outputs an error signal from which the interference estimation signal is removed from the received signal. Interference cancellation type wireless repeater. The interference canceling type wireless repeater according to claim 2 or 3, wherein the output signal of the interference control unit is used as a reference signal input to the interference control unit of the interference cancellation signal processor. The method of claim 2 or 3, wherein the interference cancellation signal processor further comprises at least one reference signal digital down converter, The digital down converter of the reference signal is inputted with an output signal of the digital up converter, and converts the input signal into a baseband signal for each channel, filters the filtered signal, and then outputs a reference signal of the corresponding channel converted to a preset sampling rate. , The reference signal of the corresponding channel output from the reference signal digital down-converter is used as a reference signal input to the interference control unit for the corresponding channel. A receiver which adjusts and transmits a received signal received from the receiving antenna; A downlink frequency converting unit converting the received signal transmitted from the receiving unit into a signal of an intermediate frequency band and outputting the converted signal; A predetermined reference signal and the received signal are input, and the received signals transmitted from the downlink frequency converter are divided for each channel, and the interference estimation signal estimated from the reference signal is generated by using an adaptive filter. An interference cancellation signal processor for removing the interference estimation signal of the corresponding channel from the received signals for each channel, and combining the received signals for each channel into one signal for transmission; An uplink frequency converter for converting a signal transmitted from the interference cancellation signal processor into a signal of an original frequency band that can be output; An amplifier for amplifying the signal transmitted from the uplink frequency converter; And A transmission antenna for transmitting a signal transmitted from the amplifier; And the reference signal is a signal converted from an output signal of any one of the interference cancellation signal processor, the uplink frequency converter, and the amplification unit. Removable wireless repeater. The method of claim 6, wherein the interference cancellation signal processing unit A first A / D converter for converting an analog signal into a digital signal; A second A / D converter converting an analog reference signal into a digital signal; At least one digital receiving signal which receives the signal transmitted from the first A / D converter, converts into a baseband signal, divides each channel, and converts the received signal for the corresponding channel to a preset sampling rate. Down converter; At least one digital reference signal that receives the signal transmitted from the second A / D converter, converts the signal into a baseband signal, divides each channel, and converts the reference signal for the corresponding channel to a preset sampling rate. Down converter; At least one interference controller for outputting a corresponding channel signal from which the interference signal is removed from the received signal of the corresponding channel received from the received signal digital downconverter using the reference signal of the corresponding channel inputted from the reference signal digital downconverter; At least one digital up-converter for increasing the sampling rate of the corresponding channel signal transmitted from the interference control unit and converting the sample signal into a signal of an intermediate frequency band; A combiner for combining signals of all channels output from the at least one digital upconverter into one signal; And D / A converter for converting the signal output from the combiner into an analog signal Interference-cancelling wireless repeater comprising a. The apparatus of claim 7, wherein the interference controller includes an adaptive filter unit and an adder. The adaptive filter unit A filter coefficient adjusting unit which receives a reference signal for removing interference signals and an error signal output from the adder, and outputs filter coefficients by applying an adaptive filter algorithm; And A digital filter that receives the reference signal and filter coefficients output from the filter coefficient adjusting unit, estimates an interference signal from the reference signal, and outputs an interference estimation signal, The adder receives a received signal including an interference signal through a non-inverting terminal, receives an interference estimation signal output from the digital filter through an inverting terminal, and outputs an error signal from which the interference estimation signal is removed from the received signal. Interference cancellation type wireless repeater. The interference canceling type wireless repeater according to any one of claims 6 to 8, wherein the output signal of the interference cancellation signal processor is used as a reference signal input to the interference cancellation signal processor. The method according to any one of claims 6 to 8, wherein the output signal of the uplink frequency converter is used as a reference signal input to the interference cancellation signal processor. The interference cancellation type wireless repeater further includes an additional downlink frequency converter between the uplink frequency converter and the interference cancellation signal processor. And the additional downlink frequency converter converts an output signal of the uplink frequency converter into a signal of an intermediate frequency band and transmits the signal to the interference cancellation signal processor. The method of claim 6, wherein the output signal of the amplifier is used as a reference signal input to the interference cancellation signal processor. The interference cancellation type wireless repeater further includes an additional downlink frequency converter between the amplifier and the interference cancellation signal processor. And the additional downlink frequency converter converts the output signal of the amplifier into a signal of an intermediate frequency band and transmits the signal to the interference cancellation signal processor.

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