JP2009522908A - Interference canceling wireless repeater - Google Patents

Abstract

The present invention relates to an interference cancellation type wireless repeater. The interference cancellation type radio repeater is for removing an interference signal that causes a radio signal radiated from a transmission antenna to be re-received by a reception antenna after passing through a plurality of paths and causes oscillation or other signal quality degradation. It is. The interference cancellation type wireless repeater according to the present invention can efficiently remove an interference signal in which a transmission signal is re-received by a reception antenna by using an adaptive filter. In addition, the interference cancellation type wireless repeater according to the present invention may be configured to divide the received signal into a plurality of bands or channels of all frequency bands of the received signal when the received signal is a broadband or multi-channel radio signal. By processing the above, it is possible to easily implement the adaptive filter and improve the interference removal performance.
[Selection] Figure 2

Description

  The present invention relates to an interference cancellation type radio repeater used in a radio communication system, and more specifically, an adaptive filter is applied to remove an interference signal from a received signal, or a received radio signal has a wide band. Or an interference removal type wireless repeater that removes the interference signal by applying an adaptive filter to each signal after dividing the signal into multiple small bands or multiple channels. About.

  A repeater is located between the base station and the terminal station and amplifies the low received signal level to a good call quality level, so that radio waves cannot reach and the strength of the radio waves is weak. A device for providing a good call quality in a building or inside a building which is a large area. The 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 radio wave shadow areas generated during operation of the wireless communication system and improve call quality. The frequency of the received signal and the frequency of the transmitted signal are different. Means a repeater operated in the same way.

  The general mobile radio relay apparatus shown in FIG. 1 is a relay apparatus 10 that uses the same transmission / reception frequency, and receives a radio wave from a base station, amplifies it, and then radiates it to a service area. A link and a reverse link that receives radio waves from the service area, amplifies them, and transmits them to the base station. 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 receiving antenna 100 and then input to the reception filter unit 110, the reception filter unit 110 performs band-pass filtering on the received signal and then performs filtering. The received signal is transmitted to the amplification unit 120. Next, the amplifying unit 120 amplifies the filtered received signal and then transmits the amplified signal to the service area via the transmission antenna 130. However, as shown in FIG. 1, the wireless repeater 10 having only the function of amplifying and transmitting the received signal does not have good isolation between the transmission and reception antennas, and transmitted from the transmission antenna 130. Since the signal is fed back to the receiving antenna 100 again, amplified together with the original signal, and sent back to the transmitting antenna, the repeater oscillates. Such an oscillation situation causes more problems in a large-sized radio repeater having a strong transmission signal from the transmission antenna.

  Therefore, in order to sufficiently remove the feedback signal to the receiving antenna that causes the oscillation state as described above, the wireless repeater is generally installed in a remote place by separating the transmitting antenna and the receiving antenna and between the transmitting and receiving antennas. A directional antenna that increases the degree of separation and has excellent directivity is used. However, since the transmission / reception antennas must be installed far apart so that the distance between the transmission / reception antennas is larger than the repeater gain, there is a disadvantage that the installation cost increases, and the feedback status of the transmission signal is sufficiently In order to alleviate this, there is a constraint that the gain of the repeater must be reduced.

  In order to solve such problems, conventionally, in order to improve the correlation distance of the relay base station, transmission and reception antenna shielding obstacles are installed, spatial separation is performed, and frequency conversion relay is performed. Although the phase signal processing method and the like are used in the smart antenna technology, there are problems that it is troublesome to install the shielding object and requires an expensive signal processing device.

  In recent years, various methods for removing the above-described interference signal from a received signal by applying a digital signal processing technique have been proposed. Most of the proposed schemes, etc., estimate the reflected signal reflected from the antenna and surrounding obstacles and cancel it from the received signal. Not only is the estimation difficult, but the estimation takes a long time, and there is a problem that real-time interference removal due to changes in the surrounding environment is almost impossible. Therefore, the conventionally proposed method is not suitable for actual use in terms of performance, and as a result, its use in an actual field environment is very restrictive.

The object of the present invention to solve the above-described problems is to apply an adaptive filter to effectively remove the interference signal that is received from the transmission antenna and received again from the reception antenna. It is to provide a type wireless repeater.
Another object of the present invention is to divide the received signal into a plurality of open frequency bands when the received radio signal is a wideband signal or a multi-channel signal, or for each channel. By dividing and applying an adaptive filter to the divided signal to remove the interference signal, the interference signal with a long delay time can be efficiently removed, and the adaptive type with fast interference removal performance An object of the present invention is to provide an interference cancellation type wireless repeater that can efficiently implement a filter.

A feature of the present invention for achieving the technical problem described above relates to an interference cancellation type radio repeater that removes an interference signal from a received signal, and the interference cancellation type radio repeater includes:
A receiver for adjusting the gain of the received signal received from the receiving antenna and transmitting the received signal;
A downward frequency converter that converts the received signal transmitted from the receiver into a signal of an intermediate frequency band and outputs the signal;
The received signal transmitted from the downward frequency converter is divided into at least one channel, and after using an adaptive filter to remove an interference signal from the divided received signal by channel, the divided signal is divided into channels. An interference cancellation signal processing unit for combining and transmitting the received signal as one signal;
An upward frequency converter that converts the signal transmitted from the interference cancellation signal processing unit into a signal in an original frequency band that can be output and outputs the signal,
An amplifying unit for amplifying the signal transmitted from the upward frequency converting unit;
A transmission antenna for transmitting a signal transmitted from the amplification unit,
The interference cancellation signal processing unit
An A / D converter for converting an analog type received signal into a digital type signal;
The signal transmitted from the A / D converter is received and converted to a baseband signal, and is divided for each channel, and then the received signal for the corresponding channel is converted and output at a preset sampling rate. One or more received signal digital downward transducers;
At least one interference control unit that outputs a corresponding channel signal obtained by removing an interference signal from a received signal of the corresponding channel received from the received signal digital downward converter using a predetermined reference signal;
Increasing the sampling rate of the corresponding channel signal transmitted from the interference control unit, converting the signal into an intermediate frequency band signal and outputting it, and at least one digital upward converter;
A combiner for combining signals of all channels output from the at least one digital upward converter as one signal;
A D / A converter that converts the signal output from the coupler into an analog signal;
The interference control unit
An adaptive filter unit that receives a reference signal for removing the interference signal, estimates an interference signal from the reference signal by applying an adaptive filter algorithm, and outputs an interference estimation signal;
The received signal including the interference signal is input to the non-inverting terminal, the interference estimation signal output from the adaptive filter unit is input to the inverting terminal, and an error signal from which the interference estimation signal is removed from the received signal is output. An adder,
The adaptive filter unit is
A filter coefficient adjustment unit that receives the reference signal and the error signal output from the adder, and outputs a filter coefficient that is adjusted in real time for each signal sample (sample) by an adaptive filter algorithm;
A digital filter that receives the reference signal and the filter coefficient output from the filter coefficient adjustment unit, and outputs an interference estimation signal generated by digital filtering of the reference signal.
In the interference cancellation type wireless repeater having the above-described characteristics, it is preferable to use the output signal of the interference control unit as a reference signal input to the interference control unit of the interference cancellation signal processing unit.
An interference cancellation type wireless repeater according to another aspect of the present invention further includes at least one reference signal digital downward converter in the above-described interference cancellation type wireless repeater,
The reference signal digital downward converter receives the output signal of the digital upward converter of the corresponding channel, converts the input signal into a baseband signal for each channel, and then sets the sampling rate to a predetermined sample. It is characterized by being converted and output with a conversion rate,
The output signal of the reference signal digital downward converter is used as a reference signal input to the interference control unit of the interference removal signal processing unit.
An interference cancellation type wireless repeater according to still another aspect of the present invention provides:
A receiver for adjusting the gain of the received signal received from the receiving antenna and transmitting the received signal;
A downward frequency converter that converts the received signal transmitted from the receiver into a signal of an intermediate frequency band and outputs the signal;
A predetermined reference signal and the received signal are input, the received signal transmitted from the downward frequency converter is divided for each channel, and an interference estimation signal estimated from the reference signal is extracted using an adaptive filter. Then, after removing the interference estimation signal of the corresponding channel from the divided reception signal for each channel, an interference cancellation signal processing unit that combines and transmits the reception signals for each channel as one signal,
An upward frequency converter that converts the signal transmitted from the interference cancellation signal processing unit into a signal in an original frequency band that can be output and outputs the signal,
An amplifying unit for amplifying the signal transmitted from the upward frequency converting unit;
A transmission antenna for transmitting a signal transmitted from the amplification unit,
The interference cancellation signal processing unit
A first A / D converter for converting an analog received signal into a digital signal;
A second A / D converter that converts an analog reference signal into a digital signal;
The signal transmitted from the first A / D converter is received and converted into a baseband signal, and is divided for each channel, and then the received signal for the corresponding channel is converted at a preset sampling rate. At least one received signal digital downward converter for outputting;
The signal transmitted from the second A / D converter is received and converted into a baseband signal, and is divided for each channel, and then the reference signal for the corresponding channel is converted at a preset sampling rate. At least one reference signal digital downward converter to output;
The interference estimation signal is generated using the reference signal of the corresponding channel input from the reference signal digital downward converter, and the interference estimation signal is removed from the reception signal of the corresponding channel received from the reception signal digital downward converter At least one interference control unit that outputs a channel signal;
Increasing the sampling rate of the corresponding channel signal transmitted from the interference control unit, converting the signal into an intermediate frequency band signal and outputting it, and at least one digital upward converter;
A combiner for combining signals of all channels output from the at least one digital upward converter as one signal;
And a D / A converter that converts the signal output from the coupler into an analog signal.
In the interference cancellation type wireless repeater having the above-described characteristics, it is preferable to use the output signal of the interference cancellation signal processing unit as a reference signal input to the interference cancellation signal processing unit.
On the other hand, an interference cancellation type radio repeater according to another aspect of the present invention is the above-described interference cancellation type radio repeater, wherein the output signal of the upward frequency conversion unit is used as a reference signal input to the interference cancellation signal processing unit. use,
The interference cancellation wireless repeater further includes an additional downward frequency conversion unit between the upward frequency conversion unit and the interference cancellation signal processing unit,
The additional downward frequency conversion unit converts the output signal of the upward frequency conversion unit into a signal of an intermediate frequency band and transmits the signal to the interference cancellation signal processing unit.
An interference cancellation wireless repeater according to still another aspect of the present invention uses the output signal of the amplifying unit as a reference signal input to the interference cancellation signal processing unit in the interference cancellation wireless repeater described above,
The interference cancellation type wireless repeater further includes an additional downward frequency conversion unit between the amplification unit and the interference cancellation signal processing unit,
The additional downward frequency converting unit converts the output signal of the amplifying unit into an intermediate frequency band signal and transmits the signal to the interference cancellation signal processing unit.

Unlike conventional relays that track each feedback signal by path, the repeater according to the present invention not only can simultaneously remove feedback interference signals as a whole by an adaptive filter algorithm that uses a transmission signal as a reference signal. Real-time removal is also possible.
According to the present invention, the interference cancellation time can be reduced by dividing the received signal into a plurality of bands or channels. Here, the interference removal time means a time required for removing the interference signal of the system and reaching a stable signal quality when a change in the external channel occurs 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 removing unit by processing the received signal by dividing it into each channel.
In addition, according to the present invention, by dividing and processing a reception signal composed of multiplexed channels for each channel, it is possible to control the on / off of the signal for each channel and to adjust the gain.

<First Embodiment>
Hereinafter, the configuration and operation of the interference cancellation type wireless repeater according to the first embodiment of the present invention will be specifically described with reference to the accompanying drawings.

  2 is a block diagram schematically showing an overall internal configuration of the interference cancellation type wireless repeater 20 according to the first embodiment of the present invention, and FIG. 3 is an interference cancellation signal processing unit 220 of FIG. FIG. 4 is a block diagram schematically showing the internal configuration of the first channel interference control unit 330 of FIG.

  First, referring to FIG. 2, the interference cancellation type wireless repeater 20 according to the first embodiment of the present invention includes a reception antenna 200, a transmission antenna 242, a reception unit 202, and a first downward frequency conversion unit. (Frequency Down Converter) 210, interference cancellation signal processing unit 220, upward frequency conversion unit (Frequency Up Converter) 230, amplification unit 240, second downward frequency conversion unit 250, and gain adjustment unit 260, Prepare. Hereinafter, each component of the interference cancellation type | mold radio repeater 20 mentioned above is demonstrated concretely.

  The receiving unit 202 receives a radio signal from the receiving antenna 200, adjusts the gain to an appropriate level, and transmits the radio signal to the first downward frequency converting unit 210.

  The first downward frequency converting unit 210 converts the high-frequency radio signal received from the receiving unit 202 into an intermediate frequency IF and transmits the intermediate frequency IF to the interference removal signal processing unit 220. In this case, the signal transmitted from the first downward frequency conversion unit 210 to the interference cancellation signal processing unit 220 is the same as the signal output from the repeater transmitted from the transmission antenna and the interference signal received again by the reception antenna. This signal is a signal obtained by combining the signal transmitted from the signal source with the signal before interference is removed.

  The second downward frequency converter 250 feeds back the signal output from the amplifier 240, converts it to an intermediate frequency, and transmits it to the interference cancellation signal processor 220. In this case, the signal input to the second downward frequency converter 250 is a signal in which the output signal of the repeater corresponds to the signal source of the interference signal component received again by the receiving antenna, and the interference removal signal processing This becomes a reference signal for removing an interference signal included in the original radio signal from the unit 220.

  The gain adjusting unit 260 adjusts the gain of the signal output from the amplifying unit 240 to an appropriate level and transmits the adjusted signal to the second downward frequency converting unit 250.

  The interference cancellation signal processing unit 220 removes an interference signal from a radio signal received from the first downward frequency converter using the reference signal received from the second downward frequency converter 250, Transmit to the upward frequency converter 230.

  The upward frequency conversion unit 230 converts the intermediate frequency signal transmitted from the interference cancellation signal processing unit 220 into an original high frequency band signal and transmits the signal to the amplification unit 240. The amplification unit 240 receives the 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 processing unit 220 will be described in detail with reference to FIGS. 3 and 4.

  Referring to FIG. 3, the interference cancellation signal processing unit 220 includes a first A / D conversion unit 300, a second A / D conversion unit 302, and at least one received signal digital downward converter ( (Digital Down Converter: hereinafter referred to as “DDC”) 310, 312, 314, at least one reference signal digital down converter 320, 322, 324, and at least one interference removing unit 330, 332, 334 , At least one or more digital up converters (hereinafter referred to as 'DUC') 340, 342, 344, an adder 350, and a D / A converter 360. The interference cancellation signal processing unit 220 having the above-described configuration receives the reception signal and the reference signal from the first downward frequency conversion unit and the second downward frequency conversion unit, respectively, and uses the reference signal to interfere with the reception signal. After the signal is removed, the reception signal from which the interference signal is removed is transmitted to the upward frequency conversion unit. Hereinafter, a process in which the interference cancellation signal processing unit 220 described above removes an interference signal from a received signal using a reference signal will be described.

  The first A / D conversion unit 300 converts the analog reception signal into a digital signal and then transmits the digital signal to at least one reception signal DDC. The second A / D conversion unit 302 receives the analog reference signal. After the signal is converted into a digital signal, it is transmitted to at least one reference signal DDC.

  The received signal DDC is a digital filter for a specific band or a specific channel after converting a wide band received signal or a multi-channel mixed signal in which a plurality of channels are mixed into a baseband signal. The sample rate of the separated signal (sample rate) is converted with the lowest possible sampling rate (for example, Nyquist Rate) for the corresponding single band or channel and output. . Accordingly, the reception signal DDC of the interference cancellation type wireless repeater according to the present invention includes the number of bands or the number of channels constituting the reception signal, and the first channel reception signal DDC310, the second channel reception signal DDC310,. , The n-th channel reception signal DDC314. The first channel reception signal DDC310 transmits the digital first channel reception signal to the first channel interference control unit 330, and the second channel reception signal DDC312 receives the digital second channel reception signal. The n-th channel reception signal DDC 314 transmits the digital n-th channel reception signal to the n-th interference control unit 334.

  FIG. 5 is a spectrum for explaining the operation of the DDC module. FIG. 5 (a) is a spectrum diagram for an input signal of the DDC module, and FIG. 5 (b) is a diagram of the DDC module. It is a spectrum figure with respect to an output signal. In FIG. 5, fs1 is the sampling rate of the input signal to the DDC, and fs2 is the sampling rate of the output signal to the DDC. Referring to FIGS. 5A and 5B, a multiplexed channel signal in which a plurality of channels are mixed is input to the DDC, and a signal of the i-th channel, which is a specific channel, is separated to obtain a sampling rate. Is output in a form reduced from fs1 to fs2.

  On the other hand, the reference signal DDC converts a received signal in which a plurality of channels are mixed into a baseband signal, then separates a signal of a specific channel, and sets the sampling rate of the separated signal to the sample of the received signal DDC. Convert and output in the same way as conversion rate. Accordingly, the reference signals DDC of the interference cancellation type wireless repeater according to the present invention are provided in the same number as the received signals DDC, and the first channel reference signal DDC320, the second channel reference signal DDC322,. Channel reference signal DDC324. Since the reference signal DDC operates in the same manner as the reception signal DDC described above, a specific description thereof is omitted. The first channel reference signal DDC 320 transmits a digital first channel reference signal to the first channel interference control unit 330, and the second channel reference signal DDC 322 receives a digital second channel reception signal. The n-th channel reference signal DDC 324 transmits the digital n-th channel reference signal to the n-th interference control unit 334.

  The interference controller applies an adaptive filter, removes the interference estimation signal of each channel estimated from the reference signal from the received signal of the corresponding channel, and outputs the first channel. It comprises an interference control unit 330, a second channel interference control unit 332,..., An nth channel interference control unit 334. FIG. 4 is a block diagram schematically showing the configuration of the first channel interference control unit 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 adjustment unit 404. Become.

  The digital filter 402 is implemented in the form of a finite impulse response filter (hereinafter referred to as “FIR filter”), and includes a first channel reference signal and a filter coefficient output from the first channel reference signal DDC. The filter coefficient output from the adjustment unit 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 obtained by estimating a feedback type interference signal in which the output signal of the corresponding channel of the wireless repeater is received again by the reception antenna via a plurality of paths.

  The filter coefficient adjustment unit 404 receives the reference signal of the corresponding channel and the error signal e output from the adder 410, and outputs a filter coefficient adjusted in real time by an adaptive filter algorithm to the digital filter 402. To do. The filter coefficient is a numerical value adjusted in real time in order to minimize an error component by the adaptive filter algorithm, and the convergence speed of the adaptive filter algorithm increases as the number of tabs decreases. Become. The number of tabs (Ntab) of the FIR filter is determined by the removable signal delay time (tdelay) and the signal sampling rate (fsample). As a result, the interference removal time of the adaptive filter unit becomes faster as the removable signal delay time is shorter and the sampling rate is lower. Since the adaptive filter algorithm for adjusting the coefficients of the FIR filter must operate for each sample of the signal, if the time interval between samples is short, the processing time of the adaptive filter algorithm is limited. The problem that it becomes difficult to implement will occur. In order to solve such a problem, the interference canceling type wireless repeater according to the present invention uses each adaptive channel to reduce the sampling rate of the signal after dividing each channel. Using a method of applying an adaptive filter separately enables actual 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 output signal of the adaptive filter is input to the inverting terminal of the adder 410. A certain interference estimation signal is input, and the adder 410 outputs an error signal e obtained by removing the interference estimation signal from the first channel reception signal. The error signal e output from the adder is input to the filter coefficient adjustment unit 404 and used as a signal for adjusting the coefficient of each tab of the digital filter in real time by the adaptive filter algorithm, and the filter coefficient adjustment unit 404 operates so as to change a coefficient such as a tab of the digital filter in a direction to minimize the power of the error signal e described above.

  Therefore, 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 the first channel signal that is the output signal of the first interference control unit 330. . Through this process, the first channel signal output from the adder is transmitted to a first channel digital up converter (hereinafter referred to as 'DUC') 340.

  The digital upward converter DUC increases the sampling rate of the signal processed in the base band, and then converts the signal into a carrier frequency on the intermediate frequency. The interference canceling wireless relay according to the present invention The unit divides the received signal for each channel and processes it, so that it comprises a first channel DUC 340, a second channel DUC 342,..., An nth channel DUC 344. 6A and 6B are spectrum diagrams for the input signal and output signal of the DUC, respectively. Here, fs2 refers to the sampling rate for the DUC input signal, and fs1 refers to the sampling rate for the DUC output signal. The first channel DUC 340 receives a first channel signal that is an output signal of the first channel interference control unit 330, increases the sampling rate, and converts the signal into a carrier frequency signal on an intermediate frequency. The first channel signal is output. A first channel signal output from the first channel DUC, a second channel DUC,..., An nth channel DUC, a second channel signal,. Are input to the combiner 350, combined into one signal, converted to an analog signal by the D / A converter 360, and output.

  The interference cancellation type wireless repeater according to the present invention having the above-described configuration reduces the frequency bandwidth by processing the received signal separately for each channel, resulting in a lower sampling rate due to DDC. As a result, the number of tabs of the adaptive filter is reduced for the same removable interference delay time. Therefore, not only the convergence speed of the adaptive filter algorithm is shortened and the interference removal time is reduced, but also the time interval between each signal sample is increased, and the implementation of the algorithm is facilitated. In addition, the interference cancellation type wireless repeater according to the present invention is not only capable of on-off control for each channel, but also allows gain adjustment, and can also measure power for each channel. Thus, a plurality of additional functions can be realized by operating the equipment.

Second Embodiment An interference cancellation type wireless repeater according to a second embodiment of the present invention uses a signal extracted from point B in FIG. 2 as a reference signal input to the interference cancellation signal processing unit. 2, the signal extracted from the point B in FIG. 2 is input to the second downward frequency conversion unit via the gain adjustment unit, and the signal input to the second downward frequency conversion unit is converted to an intermediate frequency signal. And transmitted to the interference cancellation signal processing unit.

Third Embodiment Hereinafter, the configuration and operation of an interference cancellation type wireless repeater according to a third embodiment of the present invention will be described in detail with reference to FIG. Referring to FIG. 7, the interference cancellation type wireless repeater 70 according to the third embodiment includes a reception unit 702, a downward frequency conversion unit 710, an interference cancellation signal processing unit 720, an upward frequency conversion unit 730, and an amplification. The unit 740 includes a transmission antenna and a reception antenna. The interference cancellation type radio repeater 70 according to the third embodiment is used after adjusting the gain of the signal output from the interference cancellation signal processing unit 720 as the reference signal of the interference cancellation signal processing unit 720. Since the configurations and operations of the other components of the interference cancellation type wireless repeater 70 according to the third embodiment are the same as those of the first embodiment, redundant description will be omitted.

Fourth Embodiment Hereinafter, with reference to FIGS. 8 and 9, the configuration and operation of an interference cancellation wireless repeater 80 according to a fourth embodiment of the present invention will be described in detail. FIG. 8 is a block diagram schematically showing an overall configuration of an interference cancellation type wireless repeater 80 according to the fourth embodiment of the present invention, and FIG. 9 is an interference cancellation according to the fourth embodiment of the present invention. FIG. 6 is a block diagram schematically showing an internal configuration of an interference cancellation signal processing unit 820 of the type wireless repeater 80.

  Referring to FIG. 8, an interference cancellation type radio repeater 80 according to a fourth embodiment of the present invention includes a reception antenna 800, a reception unit 802, a downward frequency conversion unit 810, an interference cancellation signal processing unit 820, The upward frequency conversion unit 830, the amplification unit 840, and the transmission antenna 842 are provided, and the internal configuration and operation of other components except the interference cancellation signal processing unit 820 are the same as those of the first embodiment. Because of this, overlapping explanation is omitted.

  Referring to FIG. 9, the interference cancellation signal processing unit 820 of the interference cancellation type wireless repeater 80 according to the fourth embodiment of the present invention includes an A / D conversion unit 900, first, second,. The received signal DDCs 910, 912, 914, the first, second,..., N channel reference signals DDCs 920, 922, 924, the first, second,. , N channels DUC 940, 942, 944, an adder 950, and a D / A converter 960. The interference cancellation signal processing unit 820 of the interference cancellation type wireless repeater 80 according to the present embodiment uses the output signals of the first, second,..., N channel DUCs 940, 942, and 944 as reference signals for interference cancellation. use. Therefore, unlike the interference cancellation type radio relay of the first to third embodiments described above, the reference signal of the interference control unit 930 of the interference cancellation type radio repeater 80 according to the fourth embodiment is different from A / It is not necessary to go through the D conversion process.

Fifth Embodiment Hereinafter, the configuration and operation of an interference cancellation type wireless repeater according to a fifth embodiment of the present invention will be described. The overall configuration of the interference cancellation type radio repeater according to the fifth embodiment of the present invention is the same as that of the interference cancellation type radio relay of the fourth embodiment, and only the configuration of the interference cancellation signal processing unit is different. Yes. FIG. 10 is a block diagram schematically showing the configuration of the interference cancellation signal processing unit of the interference cancellation type wireless repeater according to the fifth embodiment of the present invention. Referring to FIG. 10, the interference cancellation signal processing unit according to the present embodiment includes an A / D conversion unit 1000, first, second and n-th channel reception signals DDCs 1010, 1012,. , ..., n channel interference control units 1030, 1032, ..., 1034, first, second, ..., n channel DUCs 1040, 1042, ..., 1044, an adder 1050, and a D / A conversion unit 1060, Is provided. The first, second,..., N channel interference control units 1030, 1032, 1034 of the interference cancellation signal processing unit according to the present embodiment are first, second,..., N as reference signals for removing the interference signals. The output signal of the channel interference control unit is used as it is.

  Although the present invention has been described above with reference to the preferred embodiment, this is merely an example, and is not intended to limit the present invention. Those who have ordinary knowledge in the field to which the present invention belongs will be described. For example, it will be understood that a plurality of modifications and applications not exemplified above are possible without departing from the essential characteristics of the present invention. For example, in the embodiment of the present invention, the reference signal detection point for removing the interference signal from the received signal can be variously modified to improve the performance of the wireless repeater and the adaptive filter. Is. And the difference regarding such a deformation | transformation and application should be analyzed that it is contained in the range of this invention prescribed | regulated in an attached claim.

  The interference cancellation type wireless repeater according to the present invention can be widely used in wireless communication systems.

It is a block diagram which shows schematically the conventional wireless relay apparatus using the same transmission / reception frequency. 1 is a block diagram schematically showing an overall configuration of an interference cancellation type wireless repeater according to a first embodiment of the present invention. FIG. 3 is a block diagram schematically showing a configuration of an interference cancellation signal processing unit of the interference cancellation type wireless repeater of FIG. 2. FIG. 4 is a block diagram schematically showing a configuration of an interference control unit of the interference cancellation signal processing unit of FIG. 3. It is a spectrum figure with respect to the input signal and output signal of a digital downward converter. It is a spectrum figure with respect to the input signal and output signal of a digital upward converter. It is a block diagram which shows roughly the whole structure of the interference cancellation type | mold radio repeater which concerns on 3rd Embodiment of this invention. It is a block diagram which shows roughly the whole structure of the interference cancellation type | mold radio repeater which concerns on 4th Embodiment of this invention. It is a block diagram which shows roughly the structure of the interference cancellation signal process part of the interference cancellation type | mold radio repeater which concerns on 4th Embodiment of this invention. It is a block diagram which shows roughly the structure of the interference cancellation signal process part of the interference cancellation type | mold radio repeater which concerns on 5th Embodiment of this invention.

Explanation of symbols

202 receiving section 210 first downward frequency converting section 250 second downward frequency converting section 220 interference cancellation signal processing section 260 gain adjusting section 230 upward frequency converting section 240 amplifying section 300 first A / D converting section 310 first Channel reception signal DDC
312 Second channel received signal DDC
314 nth channel received signal DDC
330 First Channel Interference Control Unit 332 Second Channel Interference Control Unit 334 nth Channel Interference Control Unit 340 First Channel DUC
342 Second channel DUC
344 nth channel DUC
360 D / A converter 302 Second A / D converter 320 First channel reference signal DDC
322 Second channel reference signal DDC
324 nth channel reference signal DDC
400 adaptive filter unit 402 digital filter 404 filter coefficient adjustment unit 702 reception unit 710 first downward frequency conversion unit 720 interference cancellation signal processing unit 760 gain adjustment unit 730 upward frequency conversion unit 740 amplification unit 802 reception unit 810 downward frequency conversion unit 820 Interference cancellation signal processing unit 830 Upward frequency conversion unit 840 Amplification unit 900 A / D conversion unit 910 First channel received signal DDC
912 Second channel received signal DDC
914 nth channel received signal DDC
930 1st channel interference control unit 932 2nd channel interference control unit 934 nth channel interference control unit 940 1st channel DUC
942 Second channel DUC
944 nth channel DUC
960 D / A converter 920 First channel reference signal DDC
922 Second channel reference signal DDC
924 nth channel reference signal DDC

Claims (11)

A receiver for adjusting the gain of the received signal received from the receiving antenna and transmitting the received signal;
A downward frequency converter that converts the received signal transmitted from the receiver into a signal of an intermediate frequency band and outputs the signal;
The received signal transmitted from the downward frequency converter is divided into at least one band or at least one channel, and after removing an interference signal from the divided channel signal using an adaptive filter, An interference cancellation signal processing unit for combining and transmitting the divided channel signals as one signal;
An upward frequency converter that converts the signal transmitted from the interference cancellation signal processing unit into a signal in an original frequency band that can be output and outputs the signal,
An amplifying unit for amplifying the signal transmitted from the upward frequency converting unit;
A transmission antenna for transmitting a signal transmitted from the amplification unit;
An interference canceling type wireless repeater that removes an interference signal from a received signal and outputs the signal. The interference cancellation signal processing unit
An A / D converter for converting an analog type received signal into a digital type signal;
The signal transmitted from the A / D converter is received, converted into a baseband signal, divided for each channel, and the received signal for the corresponding channel is converted and output at a preset sampling rate. At least one received signal digital downward converter;
At least one interference control unit that outputs a corresponding channel signal obtained by removing an interference signal from a received signal of the corresponding channel received from the received signal digital downward converter using a predetermined reference signal;
Increasing the sampling rate of the corresponding channel signal transmitted from the interference control unit, converting the signal into an intermediate frequency band signal and outputting it, and at least one digital upward converter;
A combiner for combining signals of all channels output from the at least one digital upward converter as one signal;
A D / A converter for converting the signal output from the coupler into an analog signal;
The interference cancellation type | mold radio repeater of Claim 1 characterized by the above-mentioned. The interference control unit includes an adaptive filter unit and an adder,
The adaptive filter unit is
A filter coefficient adjusting unit that receives a reference signal for removing an interference signal and an error signal output from the adder, and outputs a filter coefficient by applying an adaptive filter algorithm;
A digital filter that receives the reference signal and a filter coefficient output from the filter coefficient adjustment unit, estimates an interference signal from the reference signal, and outputs an interference estimation signal;
The adder receives a reception signal including an interference signal as a non-inverting terminal, inputs an interference estimation signal output from the digital filter as an inverting terminal, and removes the interference estimation signal from the reception signal. The interference cancellation type wireless repeater according to claim 2, wherein   The interference cancellation type wireless repeater according to claim 2 or 3, wherein an output signal of the interference control unit is used as a reference signal input to the interference control unit of the interference cancellation signal processing unit. The interference cancellation signal processing unit further includes at least one reference signal digital downward converter,
The reference signal digital down converter receives the output signal of the digital up converter, converts the input signal into a baseband signal for each channel, filters, and then sets a preset sampling rate. Output the reference signal of the corresponding channel converted in
4. The interference cancellation type according to claim 2, wherein the reference signal of the corresponding channel output from the reference signal digital downward converter is used as a reference signal input to an interference control unit for the corresponding channel. Wireless repeater. A receiver for adjusting the gain of the received signal received from the receiving antenna and transmitting the received signal;
A downward frequency converter that converts the received signal transmitted from the receiver into a signal of an intermediate frequency band and outputs the signal;
A predetermined reference signal and the received signal are input, the received signal transmitted from the downward frequency converter is divided for each channel, and an interference estimation signal estimated from the reference signal is generated using an adaptive filter. An interference cancellation signal processing unit for removing the interference estimation signal of the corresponding channel from the divided reception signal for each channel and then combining and transmitting the divided reception signals for each channel as one signal;
An upward frequency converter that converts the signal transmitted from the interference cancellation signal processing unit into a signal in an original frequency band that can be output and outputs the signal,
An amplifying unit for amplifying the signal transmitted from the upward frequency converting unit;
A transmission antenna for transmitting a signal transmitted from the amplification unit;
An interference canceling type wireless repeater that removes an interference signal from a received signal and outputs the signal. The interference cancellation signal processing unit
A first A / D converter for converting an analog received signal into a digital signal;
A second A / D converter that converts an analog reference signal into a digital signal;
The signal transmitted from the first A / D converter is received and converted into a baseband signal, and is divided for each channel, and then the received signal for the corresponding channel is converted at a preset sampling rate. At least one received signal digital downward converter for outputting;
The signal transmitted from the second A / D converter is received and converted into a baseband signal, and is divided for each channel, and then the reference signal for the corresponding channel is converted at a preset sampling rate. At least one reference signal digital downward converter to output;
Using the reference signal of the corresponding channel input from the reference signal digital downward converter, at least one of outputting the corresponding channel signal obtained by removing the interference signal from the reception signal of the corresponding channel received from the reception signal digital downward converter. Two or more interference control units;
Increasing the sampling rate of the corresponding channel signal transmitted from the interference control unit, converting the signal into an intermediate frequency band signal and outputting it, and at least one digital upward converter;
A combiner for combining signals of all channels output from the at least one digital upward converter as one signal;
A D / A converter for converting the signal output from the coupler into an analog signal;
The interference cancellation type | mold radio repeater of Claim 6 characterized by the above-mentioned. The interference control unit includes an adaptive filter unit and an adder,
The adaptive filter unit is
A filter coefficient adjusting unit that receives a reference signal for removing an interference signal and an error signal output from the adder, and outputs a filter coefficient by applying an adaptive filter algorithm;
A digital filter that receives the reference signal and a filter coefficient output from the filter coefficient adjustment unit, estimates an interference signal from the reference signal, and outputs an interference estimation signal;
The adder receives a reception signal including an interference signal as a non-inverting terminal, inputs an interference estimation signal output from the digital filter as an inverting terminal, and removes the interference estimation signal from the reception signal. The interference cancellation type wireless repeater according to claim 7, wherein:   9. The interference cancellation type wireless repeater according to claim 6, wherein an output signal of the interference cancellation signal processing unit is used as a reference signal input to the interference cancellation signal processing unit. Using the output signal of the upward frequency conversion unit as a reference signal input to the interference cancellation signal processing unit,
The interference cancellation wireless repeater further includes an additional downward frequency conversion unit between the upward frequency conversion unit and the interference cancellation signal processing unit,
9. The additional downward frequency conversion unit converts the output signal of the upward frequency conversion unit into an intermediate frequency band signal and transmits the signal to the interference cancellation signal processing unit. The interference canceling type wireless repeater described. Using the output signal of the amplification unit as a reference signal input to the interference cancellation signal processing unit,
The interference cancellation type wireless repeater further includes an additional downward frequency conversion unit between the amplification unit and the interference cancellation signal processing unit,
The said additional downward frequency conversion part converts the output signal of the said amplification part into the signal of an intermediate frequency band, and transmits to the said interference removal signal processing part, The Claim 6 characterized by the above-mentioned. Interference canceling type wireless repeater.

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