KR20090065408A - On-channel repeater and its method - Google Patents

Abstract

An on channel repeater and a method thereof are provided to compensate for channel distortion occurring between a main transmitter and a repeater, thereby transmitting an output signal of high quality which is similar to a transmitting signal of the main transmitter the most through the on channel. The first subtraction unit(903) subtracts a feedback signal and a replica of a multi path signal from a signal of receiving units(901,902). A replica generating unit(913) generates each filter coefficient in a pilot section and a data section. The replica generating unit generates the feedback signal and the replica of the multi path signal by using the generated filter coefficient. Transmitting units(911,912) transmit an output signal from the first subtraction unit.

Description

On-channel repeater and its method

The present invention relates to an on-channel repeater and a method thereof, and more particularly, due to low isolation of a multipath signal and a transmit / receive antenna occurring in a transmission path between a main transmitter and the same channel repeater. The present invention relates to a co-channel repeater and a method for eliminating the feedback signal caused to increase the transmission power of the retransmission signal of the co-channel repeater and to improve the signal quality.

The present invention is derived from a study conducted as part of the IT growth engine technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development. RF relay technology development].

In general, the relay device is installed in a region where the signal of the main transmitter is weakly received, thereby relieving reception anxiety and widening the transmission region of the main transmitter signal.

1 is a configuration diagram of an exemplary relay system according to the related art, and illustrates a case in which different repeaters use different frequencies.

As shown in Fig. 1, the main transmitter 101 transmits a signal of frequency A, and each of the repeaters 102 to 105 relays the signal at frequencies B, C, D, and E that are different from the frequency A. . Since the conventional relay system relays signals using different frequencies B, C, D, and E for each of the relay devices 102 to 105, it is required to secure a plurality of frequency bands in order to configure the relay system. As such, a plurality of frequency resources are used for the relay system, which is inefficient in terms of frequency utilization.

If a plurality of repeaters use the same frequency as the main transmitter, the frequency utilization efficiency can be improved since the frequency can be reused even in a short range region.

2 is a configuration diagram of another embodiment of a conventional relay system, and illustrates a case where the same frequency is used between relay apparatuses.

That is, the main transmitter 201 transmits a signal of frequency A, and each of the co-channel relays 202 to 205 also relays the signal at frequency A.

In order to enable such co-channel relay, signals of the same frequency transmitted from the main transmitter 201 and the co-channel repeaters 202 to 205 must be identified.

If the output signals of the same frequency band (output signals of the main transmitter and the relay device) are not identical to each other, these output signals are not removed by the equalizer or other device as co-channel interference signals in each relay device.

Also, if the signal transmitted from the main transmitter and the same channel repeater has a time delay greater than or equal to a predetermined reference, the equalizer does not remove the delay signal.

Therefore, for the same channel relay, the output signal of the same channel repeater should be the same as the output signal of the main transmitter, and the time delay of the two output signals should be small.

Meanwhile, the problems of the conventional co-channel relay will be described with reference to FIGS. 3 to 7.

Figure 3 is a configuration diagram of an embodiment of a conventional RF amplified co-channel repeater.

Referring to the configuration and operation of the conventional RF amplified co-channel repeater with reference to Figure 3, first, the receiving antenna 301 and the RF receiver 302 receives the RF signal transmitted from the main transmitter, RF bandpass filter ( 303 is a band pass only a predetermined signal band of the received RF signal, the high power amplifier 304 amplifies the band-passed RF signal, the amplified RF signal through the transmission antenna 305 in the same channel Is sent to.

4 is a block diagram of a conventional IF conversion co-channel relay.

Referring to the configuration and operation of the conventional IF conversion co-channel repeater with reference to Figure 4, first, the receiving antenna 401 and the RF receiver 402 receives the RF signal transmitted from the main transmitter, IF down converter ( 403 down converts the received RF signal to an intermediate frequency (IF) signal based on a reference frequency provided from a local oscillator (LO) 408, and an IF bandpass filter 404 converts the downconverted IF Of the signals, only a predetermined band signal is bandpassed, and the RF up-converter 405 up-converts the band-passed IF signal to an RF signal based on a reference frequency provided from a local oscillator 408, and a high-power amplifier ( 406 amplifies the upconverted RF signal, and the amplified RF signal is transmitted on the same channel through the transmit antenna 407.

5 is a configuration diagram of a conventional SAW filter co-channel repeater.

Referring to the configuration and operation of the conventional SAW filter co-channel relay with reference to Figure 5, first, the receiving antenna 501 and the RF receiver 502 receives the RF signal transmitted from the main transmitter, IF down converter ( 503 down-converts the received RF signal to an intermediate frequency (IF) signal based on a reference frequency provided from a local oscillator (LO) 508, and a SAW filter 504 converts the down-converted IF signal. Band-passed to a predetermined band signal, the RF up-converter 505 up-converts the band-passed IF signal to an RF signal based on a reference frequency provided from the local oscillator 508, and the high-power amplifier 506 The upconverted RF signal is amplified, and the amplified RF signal is transmitted on the same channel through the transmission antenna 507.

However, the co-channel repeater described with reference to FIGS. 3 to 5 includes a noise and a multipath signal caused by a transmission path between the main transmitter and the co-channel repeater, and feedback caused by low isolation of a transmit / receive antenna. Since the signal and the system noise added in the same channel relay system cannot be removed, the characteristics of the output signal are worse than the input signal.

In addition, the co-channel repeater described with reference to FIGS. 3 to 5 has a problem in that the transmit power of the co-channel repeater is limited due to a feedback signal caused by low isolation of the transmit / receive antenna.

FIG. 6 is a block diagram of a conventional demodulation type co-channel relay having a feedback signal removing function.

Referring to the configuration and operation of the conventional demodulation type co-channel repeater with reference to Figure 6, first the RF signal received through the receiving antenna 601 from the main transmitter or other repeater is a predetermined band by the RF receiver 602 Downconverted to the signal of. The subtraction unit 603 subtracts a replica of a feedback signal from a signal down-converted to a predetermined band by the RF receiver 602 to remove the feedback signal, and the replica generator 604. Based on the signal output from the subtractor 603 (which is the signal from which the feedback signal is removed), a replica of the feedback signal is generated and fed back to the subtractor 603. The RF transmitter 605 converts the signal output from the subtractor 603 (that is, the signal from which the feedback signal is removed) into an RF signal and wirelessly transmits the signal through the transmit antenna 606.

FIG. 7 is a detailed block diagram of an embodiment of the demodulation type co-channel relay of FIG. 6.

Here, the receiving antenna 701, the RF receiving unit 702, the subtracting unit 703, the RF transmitting unit 706, and the transmitting antenna 707 illustrated in FIG. 7 are the receiving antenna 601 and the RF described with reference to FIG. 6. Since it corresponds to the receiver 602, the subtractor 603, the RF transmitter 605, and the transmit antenna 606, the description thereof will be omitted.

Meanwhile, the replica generation unit 708 generates a filter coefficient for generating the filter coefficient used by the adaptive filtering unit 704 based on the signal output from the subtraction unit 703 (which is a signal from which the feedback signal has been removed). A replica of the feedback signal is generated by using the generation unit 705 and the filter coefficient received from the filter coefficient generation unit 705 and the output signal of the subtraction unit 703 to feed back to the subtraction unit 703. An adaptive filtering unit 704 is included.

)를 산출한다.At this time, the filter coefficient generation unit 705 based on the Least Mean Square (LMS) algorithm according to the following [Equation 1] filter coefficients (filter tap coefficient,

) Is calculated.

는 추정된 중계장치 수신채널의 채널 왜곡정보에 기초하여 산출되는 채널의 에러신호,

는 이전(previous) 필터계수,

는 수렴속도를 결정하는 상수이며, M은 필터 탭 수, T는 전치(transpose)를 나타낸다.here,

Is an error signal of a channel calculated on the basis of channel distortion information of the estimated relaying channel,

Is the previous filter coefficient,

Is a constant that determines the convergence rate, M is the number of filter taps, and T is the transpose.

)에 기초하여, 상기 감산부(703)에서 출력되는 시간 인덱스 n에서의 출력신호벡터(

)를 필터링하여 하기의 [수학식 2] 에 따라 궤환신호의 레플리카(

)를 산출한다.The adaptive filtering unit 704 may use the filter coefficients generated by the filter coefficient generator 705.

Based on the output signal vector at the time index n output from the subtraction section 703

) Is filtered and a replica of the feedback signal according to Equation 2 below.

) Is calculated.

)에서 상기 적응 필터링부(704)로부터 산출된 궤환신호의 레플리카(

)를 감산함으로써, 송/수신 안테나의 낮은 격리로 인해 야기된 궤환신호를 제거한다.The subtractor 703 outputs an output signal of the RF receiver 702 according to Equation 3 below.

A replica of the feedback signal calculated from the adaptive filtering unit 704 in

By subtracting), the feedback signal caused by the low isolation of the transmit / receive antenna is eliminated.

8 is a detailed block diagram of an embodiment of the filter coefficient generator 705 of FIG. 7.

As shown in FIG. 8, the filter coefficient generator 705 includes a demodulator 801, a channel estimator 802, and a time domain filter coefficient generator 803.

First, the demodulator 801 receives a signal (a signal from which a feedback signal is removed) output from the subtractor 703 and demodulates through a frequency and timing synchronization process.

The channel estimator 802 further generates a noise and multi-path signal caused by a channel between the main transmitter and the same channel repeater based on the signal demodulated by the demodulator 801. And estimating channel distortion of the receiving device receiving channel including the residual feedback signal.

)를 생성하여 상기 [수학식 1]에 따라 필터계수를 생성한다.The time domain filter coefficient generator 803 may generate an error signal in the time domain based on the channel distortion information estimated by the channel estimator 802.

) To generate a filter coefficient according to [Equation 1].

However, although the demodulation type co-channel relay described in FIG. 6 can remove the feedback signal caused by the low isolation of the transmitting / receiving antenna, the performance of the demodulated co-channel repeater is dependent on the structure of the promised pilot signal used for the feedback channel estimation. It makes a big difference. In particular, the interval between pilots is closely related to the time interval for updating the filter coefficient, and thus, the feedback signal cannot be effectively removed in a situation where the feedback channel changes rapidly in a system having a large interval between pilots.

Due to the limitation of the feedback signal and the multi-path signal removal capability common to the conventional technology, the conventional co-channel relay system has limitations such as low utilization of the existing relay facility and high investment cost.

Therefore, the output signal of the same channel repeater is the same as the output signal of the main transmitter, the time delay of the two output signals is short, and the same by removing the noise and multipath signal caused by the transmission path between the main transmitter and the same channel repeater. The characteristics of the channel repeater output signals are superior to the input signals of the same channel repeater, and the utilization efficiency is increased by eliminating the feedback signal caused by the low isolation of the same channel repeater transmit / receive antenna. There is a need for a co-channel repeater with high cost and low investment cost.

Therefore, the present invention has been proposed to meet the above requirements, by removing the multipath signal generated in the transmission path between the main transmitter and the same channel repeater and the feedback signal caused by the low isolation of the transmit / receive antenna. SUMMARY OF THE INVENTION An object of the present invention is to provide a co-channel relay apparatus and a method for increasing the transmission power of a retransmission signal of a relay apparatus and improving signal quality.

That is, the present invention eliminates the feedback signal fed back to the receiving antenna of the repeater due to the low isolation of the RF (Radio Frequency) signal transmitted from the repeater, It is an object of the present invention to provide a co-channel repeater and a method thereof for compensating channel distortion occurring between repeaters, so as to transmit a high quality output signal in a form similar to that of a main transmitter as much as possible.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned above can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

An apparatus of the present invention for achieving the above object is a co-channel relay apparatus, comprising: receiving means for receiving a signal; First subtracting means for subtracting a 'replica of a feedback signal and a multipath signal' from the signal from the receiving means; A replica generation means for generating a filter coefficient in a pilot section and a data section, respectively, and generating the 'replica of the feedback signal and the multipath signal' using the generated filter coefficient and feeding it back to the first subtracting means; And transmission means for transmitting the output signal from the first subtraction means.

In addition, the method of the present invention for achieving the above object, in the same channel relay method, receiving a signal; A first subtraction step of subtracting a 'replica of a feedback signal and a multipath signal' from the received signal; A replica generation step of generating a filter coefficient in a pilot section and a data section, and generating the 'replica of the feedback signal and the multipath signal' using the generated filter coefficient and feeding back to the first subtraction step; And transmitting the signal whose channel distortion is compensated by removing the feedback signal and the multipath signal.

As described above, the present invention eliminates the multipath signal generated in the transmission path between the main transmitter and the co-channel repeater and the feedback signal caused by the low isolation of the transmit / receive antenna. There is an effect that can increase the transmission power and improve the signal quality.

That is, the present invention eliminates the feedback signal fed back to the receiving antenna of the repeater due to the low isolation of the RF (Radio Frequency) signal transmitted from the repeater, By compensating for the channel distortion occurring between the repeaters, it is possible to transmit a high quality output signal in the same channel as that of the main transmitter.

In addition, the present invention is to ensure that the output signal of the co-channel repeater as close as possible to the output signal of the main transmitter, the time delay with the output signal of the main transmitter is short, caused by the transmission path between the main transmitter and the co-channel repeater By eliminating the noise and multipath signal, the characteristics of the same channel repeater output signal are better than the same channel repeater input signal, and the same channel relay is removed by eliminating the feedback signal caused by low isolation of the same channel repeater transmit / receive antenna Increasing the transmit power of the device allows for high utilization and low investment.

In addition, the present invention has the effect of increasing the utilization efficiency of the limited frequency resources by relaying the signal corrected for distortion on the transmission channel.

The above objects, features, and advantages will become more apparent from the detailed description given hereinafter with reference to the accompanying drawings, and accordingly, those skilled in the art to which the present invention pertains may share the technical idea of the present invention. It will be easy to implement. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

9 is a configuration diagram of an embodiment of the same channel relay apparatus according to the present invention.

As shown in FIG. 9, the co-channel relay apparatus according to the present invention includes a receiving antenna 901, an RF receiving unit 902, a first subtracting unit 903, an RF transmitting unit 911, and a transmitting antenna 912. Filter coefficients are generated using the time domain pilot in the pilot intervals, and filter coefficients are generated using the time domain signals in the data interval, and the feedback signal and the multipath signal are generated using the generated filter coefficients. A replica generator 913 for generating a replica and feeding it back to the first subtraction unit 903 is included.

Next, the components will be described in more detail.

First, an RF signal received through a receiving antenna 901 from a main transmitter or another relay device is down-converted into a signal of a predetermined band (for example, baseband) by the RF receiver 902.

The first subtractor 903 subtracts a feedback signal and a replica of the multipath signal from the signal down-converted into a predetermined band by the RF receiver 902 to reduce the feedback signal and the multipath signal. Remove it.

The replica generator 913 generates a filter coefficient using a time domain pilot in a pilot section and a filter coefficient using a time domain signal in a data section, and uses the generated filter coefficient to feed back a feedback signal. A replica of the signal and the multipath signal are generated and fed back to the first subtractor 903.

The RF transmitter 911 up-converts the signal output from the first subtractor 903 (which is the signal from which the feedback signal and the multipath signal are removed) into an RF signal and wirelessly transmits the signal through the transmission antenna 912. . That is, the RF transmitter 911 subtracts a replica from the signal of the RF receiver 902 from the first adaptive filter 904 by the first subtractor 903 to perform channel distortion. The signal is up-converted to an RF signal for wireless transmission.

Meanwhile, the replica generator 913 includes a first adaptive filtering unit 904, a first filter coefficient generator 905, a time domain pilot storage unit 906, a second filter coefficient generator 907, and a time domain. The signal determining unit 908 and the pilot section and the data section switching section 909 and 910 are included.

That is, the replica generator 913 may use the pilot interval and the data interval switching unit 909 and 910 and the first filter coefficient generation unit 905 to determine and switch the pilot interval and the data interval. A time domain pilot storage unit 906 storing an area pilot signal, a time domain pilot signal stored in the time domain pilot storage unit 906, and a signal subtracted by the first subtraction unit 903 (a feedback signal). And a first filter coefficient generator 905 and a first subtractor for generating a filter coefficient to be used by the first adaptive filtering unit 904 during the pilot period. A time domain signal determination unit 908 for generating a determined time domain signal to be used by the second filter coefficient generation unit 907 based on the signal subtracted by 903 (the signal from which the feedback signal and the multipath signal are removed) ), The time domain The first adaptive filtering during the data period based on the time domain signal from the signal determining unit 908 and the signal subtracted by the first subtracting unit 903 (the signal from which the feedback signal and the multipath signal are removed). A second filter coefficient generator 907 for generating a filter coefficient to be used in the unit 904, and filter coefficients from the first and second filter coefficient generators 905 and 907 and the first subtractor ( A replica of the feedback signal and the multipath signal is generated based on the signal subtracted by the signal 903, which is the signal from which the feedback signal and the multipath signal are removed, and then, to the first subtraction unit 903. And a first adaptive filtering unit 904 for feeding back.

Next, the components of the replica generator 913 will be described in more detail.

)를 산출하고, 상기 [수학식 3]에 따라 상기 제 1 감산부(903)가 상기 RF 수신부(902)의 출력신호(

)에서 상기 제 1 적응 필터링부(904)로부터의 레플리카(

)를 감산한다.The first adaptive filtering unit 904 and the first subtracting unit 903 correspond to the adaptive filtering unit 704 and the subtracting unit 703 of FIG. 7, as described with reference to FIG. 7. As shown in Equation 2, the first adaptive filtering unit 904 is a replica (

), And the first subtractor 903 outputs the output signal of the RF receiver 902 according to Equation (3).

Replica from the first adaptive filtering unit 904 (

).

The first filter coefficient generation unit 905 is a noise, multipath caused by the feedback signal and the transmission path of the main transmitter and the same channel repeater based on the signal output from the first subtraction unit 903 in a pilot section. A filter coefficient to be used in the first adaptive filtering unit 904 is generated by estimating a reception channel including a signal and the like, and the time-domain pilot storage unit 906 receives the reception in the first filter coefficient generation unit 905. The time domain pilot signal required for estimating the channel is stored.

)를 산출한다.At this time, the first filter coefficient generation unit 905 is a filter coefficient to be used in the first adaptive filtering unit 904 according to Equation 4 below based on the Least Mean Square (LMS) algorithm (

) Is calculated.

은 상기 제 1 감산기(903)의 출력신호(

)와 상기 시간영역 파일럿 저장부(906)에 저장되어 있는 시간영역 파일럿 신호(

)에 기초하여 산출되는 중계장치 출력신호에 포함된 에러신호,

는 이전(previous) 필터계수,

는 수렴속도를 결정하는 상수이다. 그리고 M은 필터 탭 수, T는 전치(transpose), *는 공액(conjugate)을 각각 나타낸다.here,

Is an output signal of the first subtractor 903 (

) And the time domain pilot signal stored in the time domain pilot storage unit 906

An error signal included in the relay output signal calculated on the basis of

Is the previous filter coefficient,

Is a constant that determines the speed of convergence. M is the number of filter taps, T is the transpose, and * is the conjugate.

The second filter coefficient generator 907 generates a noise signal and a multipath caused by the feedback signal and the transmission path of the main transmitter and the same channel repeater based on the signal output from the first subtractor 903 in the data section. A filter coefficient is generated by estimating a reception channel including a signal, and the like, and the time domain signal determination unit 908 determines the determined time domain signal necessary to estimate the reception channel by the second filter coefficient generation unit 907. Occurs.

The pilot section and the data section switching unit 909 and 910 determine a pilot section and a data section (a concept including a control signal described later) and switch according to the determination result, thereby updating a filter coefficient corresponding to the section. The method is determined (selected), and the updated filter coefficient is transmitted to the first adaptive filtering unit 904 according to the determined filter coefficient updating method. In this case, the pilot section and the data section switching unit 909 and 910 may be pilots according to control signals from an internal controller (not shown) or control signals from an external processor (not shown). It can be implemented to select the interval and the data interval. In addition, the pilot interval and the data interval are already known through a standard for each system.

FIG. 10 is a detailed block diagram of an embodiment of the co-channel relay of FIG. 9.

Here, the reception antenna 1001, the RF receiver 1002, the first subtractor 1003, the first adaptive filter 1004, the first filter coefficient generator 1005, and the time domain pilot storage shown in FIG. The unit 1006, the time domain signal determiner 1011, the RF transmitter 1012, the transmit antenna 1013, and the pilot interval and data interval switching units 1014 and 1015 are the reception antennas 901 described with reference to FIG. 9. ), An RF receiver 902, a first subtractor 903, a first adaptive filtering unit 904, a first filter coefficient generator 905, a time domain pilot storage unit 906, a time domain signal determination unit ( 908, the RF transmitter 911, the transmit antenna 912, and the pilot interval and the data interval switching units 909 and 910, respectively, so a description thereof will be omitted.

Meanwhile, the second filter coefficient generator 1010 subtracts replicas of the residual feedback signal and the residual multipath signal included in the signal output from the first subtraction unit 1003 in the data section, and the residual feedback signal and the residual. A second subtractor 1007 for removing a multipath signal, a signal output from the second subtractor 1007 (a signal from which a residual feedback signal and a residual multipath signal are removed) and the time domain signal determination unit ( The error of the filter coefficients of the first adaptive filtering unit 1004 is estimated based on the determined time domain signal from 1011, and the first adaptive filtering unit 1004 and the second adaptive filtering unit 1008 are estimated. A filter coefficient error estimator 1009 for generating a filter coefficient, and a filter coefficient from the filter coefficient error estimator 1009 and a signal output from the second subtractor 1007 (a residual feedback signal and a residual multipath). Scene with signal removed Based on the Im) and comprises a residual feedback signal and a second adaptive filtering unit (1008 for generating a replica of the residual multi-path signal to feedback to the second subtracting unit 1007).

)를 생성한다.At this time, the filter coefficient error estimator 1009 is based on the Least Mean Square (LMS) algorithm according to [Equation 5] below, the filter coefficient of the second adaptive filtering unit 1008 (

)

은 상기 제 2 감산부(1007)의 출력신호,

은 상기 시간영역 신호 판정부(1011)로부터의 판정된 시간영역 신호이고,

은 상기 제 1 적응 필터링부(1004)의 필터계수가 가지는 오차이고,

은 각 데이터 구간에서의 시간 인덱스로

의 값을 가진다. 그리고

은 데이터 구간의 크기로서, 상기 시간영역 신호 판정부(1011)에서 신호를 판정하기 위해 필요한 데이터의 크기에 의해 결정될 수 있다.here,

Is an output signal of the second subtractor 1007,

Is the determined time domain signal from the time domain signal determination unit 1011,

Is an error that the filter coefficient of the first adaptive filtering unit 1004 has,

Is the time index in each data interval.

Has the value And

Is the size of the data section, and may be determined by the size of data required to determine the signal in the time domain signal determiner 1011.

)는, 일실시예로 OFDM(Orthogonal Frequency Division Multiplexing) 전송 방식을 사용하는 시스템의 경우 푸리에 변환 크기(Fourier transform size)로 결정할 수 있다.Here, the size of the data section that can be determined by the time domain signal determination unit 1011 (

) May be determined as a Fourier transform size in a system using an Orthogonal Frequency Division Multiplexing (OFDM) transmission scheme.

)가 가지는 오차를 보상한다.In addition, the filter coefficient error estimator 1008 updates the filter coefficient of the first adaptive filtering unit 1004 by using Equation 6 or Equation 7 below, thereby providing a previous filter coefficient (

Compensate for errors with).

을 이용하여

를 갱신하는 방식이다. 즉,

인덱스가

부터

까지 일 때는 제 1 적응 필터링부(1004)의 필터계수를 갱신하지 않고

인덱스가

일 때 도출되는 최종

을

에 더해 제 1 적응 필터링부(1004)의 필터계수를 갱신하는 방식이다.Equation 6 is the final calculated by Equation 5

Using

Is the way to update. In other words,

Index is

from

Until, the filter coefficient of the first adaptive filtering unit 1004 is not updated.

Index is

Is derived when

of

In addition, the filter coefficients of the first adaptive filtering unit 1004 are updated.

인덱스에서

에 더해지는 값(

)과 동일한 값을

에 더하여 제 1적응 필터링부(1004)의 필터계수를 갱신하는 방식으로, 제 2 적응 필터링부(1008)와 같이 총 N번의 갱신이 이루어진다.On the contrary, [Equation 7] is each of the [Equation 5]

In the index

The value added to (

The same value as

In addition, in a manner of updating the filter coefficient of the first adaptive filtering unit 1004, a total of N updates are performed like the second adaptive filtering unit 1008.

은

부터

까지 각각의

인덱스에서 구해지는

을 누적하여 더한 결과이므로, 상기 [수학식 6]과 상기 [수학식 7]에 의해 갱신되는 상기 제 1 적응 필터링부(1004)의 최종 필터계수는 동일하다.here,

silver

from

Until each

Obtained from the index

Since the summation result is accumulated, the final filter coefficients of the first adaptive filtering unit 1004 updated by Equation 6 and Equation 7 are the same.

)에 기초하여, 상기 제 2 감산부(1007)에서 출력되는 출력신호벡터(

)를 하기의 [수학식 8]에 따라 필터링하여 잔여 궤환신호 및 잔여 다중경로신호의 레플리카(

)를 산출한다.The second adaptive filtering unit 1008 may generate a filter coefficient generated by the filter coefficient error estimator 1009.

Based on the output signal vector outputted from the second subtractor 1007

) Is a replica of the residual feedback signal and the residual multipath signal by filtering according to Equation 8 below.

) Is calculated.

)에서 상기 제 2 적응 필터링부(1008)에서 산출된 잔여 궤환신호 및 잔여 다중경로신호의 레플리카(

)를 감산함으로써, 상기 제 1 감산부(1003)의 출력신호(

)에서 잔여 궤환신호 및 잔여 다중경로신호를 제거한다.The second subtractor 1007 may output an output signal of the first subtractor 1003 according to Equation 9 below.

A replica of the residual feedback signal and the residual multipath signal calculated by the second adaptive filtering unit 1008

) By subtracting the output signal of the first subtraction unit 1003

), Remove the residual feedback signal and the residual multipath signal.

)는 상기 필터계수 오차 추정부(1009)에 입력되어 보다 정확한 필터계수 추정 오차를 구하는데 이용되고, 이렇게 추정된 필터계수 오차는 상기 제 1 적응 필터링부(1004)의 필터계수를 갱신하는데 이용된다.Here, the output signal of the second subtraction unit 1007 (

) Is input to the filter coefficient error estimator 1009 and used to obtain a more accurate filter coefficient estimation error, and the estimated filter coefficient error is used to update the filter coefficient of the first adaptive filtering unit 1004. .

Hereinafter, the principle of filter coefficient generation of the second filter coefficient generators 907 and 1010 will be described in detail with reference to FIG. 11.

FIG. 11 estimates an error of the filter coefficients of the first adaptive filtering units 904 and 1004 in the second filter coefficient generators 907 and 1010 and based on the estimated error, the first adaptive filtering unit. Fig. 1 shows the principle of updating (compensating) the filter coefficients at (904, 1004).

는 데이터 구간에서 상기 제 1 감산부(903, 1003)의 출력을 저장한 벡터이고,

는 상기 제 1 감산부(903, 1003)의 출력신호(

)에 기초하여 상기 시간영역 신호 판정부(908, 1011)에서 판정된 시간영역 신호의 벡터이다. 그리고

은 상기 제 1 감산부(903, 1003)의 출력신호에서 잔여 궤환신호 및 잔여 다중경로신호를 제거한 신호로서, 상기 제 2 감산부(1007)의 출력에 해당하는 신호이다. 그리고

은 상기 시간영역 신호 판정부(908, 1011)에서 판정된 시간영역 신호(

)와 상기 제 2 감산부(1007)의 출력신호(

) 간의 오차로서, 상기 필터계수 오차 추정부(1009)에서 적응 알고리즘을 사용하여 최소화하고자 하는 오차에 해당한다. 그리고

은 상기 필터계수 오차 추정부(1009)에서 상기

에 기초하여 산출된 값으로 상기 제 2 적응 필터링부(1008)의 필터계수로 사용되고, 상기 제 2 적응 필터링부(1008)의 출력신호는 상기 제 1 감산부(903, 1003)의 출력신호(

)에서 잔여 궤환신호 및 잔여 다중경로신호가 제거된 상기 제 2 감산부(1007)의 출력신호(

)를 생성하는데 이용된다.In FIG. 11

Is a vector storing the outputs of the first subtractors 903 and 1003 in the data interval,

Is an output signal of the first subtracting units 903 and 1003 (

Is a vector of time-domain signals determined by the time-domain signal determination units 908 and 1011 based on " And

Is a signal obtained by removing the residual feedback signal and the residual multipath signal from the output signals of the first subtraction units 903 and 1003, and is a signal corresponding to the output of the second subtraction unit 1007. And

Is a time domain signal determined by the time domain signal determination unit 908, 1011 (

) And an output signal of the second subtractor 1007

), Which corresponds to an error to be minimized by using the adaptive algorithm in the filter coefficient error estimator 1009. And

Is determined by the filter coefficient error estimation unit 1009.

It is a value calculated based on and used as a filter coefficient of the second adaptive filtering unit 1008, and the output signal of the second adaptive filtering unit 1008 is an output signal of the first subtracting units 903 and 1003.

Output signal of the second subtractor 1007 from which the residual feedback signal and the residual multipath signal

Is used to generate

은 상기 제 1 적응 필터링부(904, 1004)가 가지는 필터계수 오차 에 해당한다. 이때,

인덱스가 증가할수록 적응 알고리즘에 의해 상기

이 작아지고, 그에 따라 상기

에 기초하여 산출되는

은 상기 제 1 적응 필터링부(904, 1004)가 가지는 필터계수 오차에 점차적으로 가까워진다.Also,

Corresponds to a filter coefficient error of the first adaptive filtering units 904 and 1004. At this time,

Reminded by the adaptive algorithm as the index increases

Becomes smaller and accordingly

Calculated based on

Is gradually closer to the filter coefficient error of the first adaptive filtering units 904 and 1004.

은

개의 데이터를 이용하여 추정할 수 있는 가장 정확한 상기 제 1 적응 필터링부(904, 1004)가 가지는 필터계수 오차 추정치라 할 수 있다.So the final calculated

silver

The filter coefficient error estimation value of the first adaptive filtering unit 904, 1004, which can be estimated using two pieces of data, is estimated.

개의 데이터를 이용하여 적응 알고리즘을 통해 상기

을 최소화시키고, 상기 최소화된

에 기초하여

를 구한 후에, 이렇게 구한

를 이용하여 상기 제 1 적응 필터링부(904, 1001)의 필터계수(

)를 갱신해 줌으로써, 동일채널 중계장치가 다중경로신호와 궤환신호가 제거된 고품질의 신호를 출력하게 된다.That is, the filter coefficient error estimation unit 1009

Through adaptive algorithm using two pieces of data

Minimized, the minimized

Based on

After you save,

Filter coefficients of the first adaptive filtering units 904 and 1001 using

), The same channel repeater outputs a high quality signal from which the multipath signal and the feedback signal are removed.

은 데이터 구간의 크기로서, 시간영역 신호를 판정하는데 필요한 데이터의 크기에 의해 결정될 수 있다.here,

Is the size of the data interval, and may be determined by the size of data required to determine the time-domain signal.

는 각 데이터 구간에 적용되기 전에 초기화되고, 각 데이터 구간에서 상기 최종

를 산출해 내는 시간은 동일채널 중계장치가 적용되는 시스템의 샘플링 주파수에 의존하지 않고, 사용되는 하드웨어의 연산속도에 의해 결정된다.Also, the

Is initialized before being applied to each data section, and the last in each data section.

The time required to calculate is not dependent on the sampling frequency of the system to which the co-channel repeater is applied, but is determined by the computational speed of the hardware used.

Meanwhile, the time domain pilot storage units 906 and 1006 and the time domain signal determination units 908 and 1011 illustrated in FIGS. 9 and 10 may be variously implemented according to a system standard.

12 and 13, time-domain pilot storage units 906 and 1006 in a terrestrial DMB standard using an orthogonal frequency division multiplexing (OFDM) transmission scheme and a differential quadrature phase shift keying (DQPSK) modulation scheme. An embodiment of the signal determination units 908 and 1011 will be described, but it is apparent that the present invention is not limited thereto.

FIG. 12 is a diagram illustrating an embodiment of a pilot to be stored in the time domain pilot storage units 906 and 1006. FIG.

As shown in FIG. 12, a frequency domain pilot 1201 corresponding to one OFDM symbol is converted into a time domain pilot 1202 through an inverse Fourier transform, and the time domain pilot 1202 is converted into a time domain pilot storage unit. (906, 1006).

FIG. 13 is a detailed configuration diagram of one embodiment of the time domain signal determination units 908 and 1011 and illustrates an exemplary configuration applicable to the terrestrial DMB standard.

The time domain signal determination unit 908, 1011 includes a Fourier transform unit 1301, a DQPSK demodulator 1302, a hard decision unit 1303, a DQPSK modulator 1304, and an inverse Fourier transform unit 1305. Each of the components 1301 to 1305 is a known technique. Therefore, here only the coupling relationship and operation of each of the above components will be described briefly.

The Fourier transformer 1301 converts a time domain signal corresponding to one OFDM symbol from an output signal of the first subtractor 1003 into a frequency domain signal, and the DQPSK demodulator 1302 is a Fourier transformer. DQPSK demodulates the frequency domain signal converted in operation 1301, the hard determination unit 1303 determines the DQPSK demodulated frequency domain signal in the DQPSK demodulation unit 1302, and the DQPSK modulator 1304 determines the rigidity. The frequency domain signal determined by the determination unit 1303 is DQPSK modulated, and the inverse Fourier transform unit 1305 converts the frequency domain signal DQPSK modulated by the DQPSK modulator 1304 into a time domain signal to determine the determined time. An area signal is output to the filter coefficient error estimator 1009.

FIG. 14 is a flowchart illustrating an embodiment of the same channel relaying method according to the present invention. Since a specific embodiment of the present invention is the same as described above, only the technical gist of the operation method will be briefly described.

First, the RF receiver 902 receives an RF signal from a main transmitter or another relay device through the reception antenna 901 and down-converts the signal to a signal of a predetermined band (for example, baseband) (1401).

Subsequently, a first subtractor 903 subtracts a replica of a feedback signal and a multipath signal from a signal down-converted to a predetermined band by the RF receiver 902 to reduce the feedback signal and the multipath. Remove the signal (1402).

Thereafter, the replica generator 913 generates a filter coefficient using a time domain pilot in a pilot section, generates a filter coefficient using a time domain signal in a data section, and uses the generated filter coefficient to feed back a feedback signal. A replica of the signal and the multipath signal is generated and fed back to the first subtractor 903 (1403).

The RF transmitter 911 up-converts the signal output from the first subtractor 903 (which is the signal from which the feedback signal and the multipath signal are removed) into an RF signal and wirelessly transmits the signal through the transmission antenna 912. (1404). That is, the RF transmitter 911 subtracts a replica from the signal of the RF receiver 902 from the first adaptive filter 904 by the first subtractor 903 to perform channel distortion. The signal is up-converted to an RF signal for wireless transmission.

FIG. 15 is a detailed flowchart of an embodiment of the replica generation process of FIG. 14, and since a specific embodiment thereof is the same as described above, only the technical gist of the operation method will be briefly described.

First, the time domain pilot storage 906 stores a time domain pilot signal to be used by the first filter coefficient generator 905 (1501).

Thereafter, the pilot section and the data section switching sections 909 and 910 determine whether the output signal from the first subtraction section 903 is a pilot section or a data section and switch (select a filter coefficient updating method) (1502).

When the determination result 1502 is determined to be a pilot section and is switched, the first filter coefficient generator 905 stores the time domain pilot signal stored in the time domain pilot storage unit 906 and the first subtractor 903. A filter coefficient to be used by the first adaptive filtering unit 904 is generated (1503) during the pilot period based on the signal subtracted by the signal (a signal in which the feedback signal and the multipath signal are removed).

On the other hand, when the determination result 1502 is determined to be a data section and is switched, the time domain signal determination unit 908 is subtracted by the first subtraction unit 903 (a signal from which a feedback signal and a multipath signal are removed). In operation 1504, the determined time domain signal to be used in the second filter coefficient generator 907 is generated.

Thereafter, the second filter coefficient generator 907 removes the time domain signal from the time domain signal determiner 908 and the signal subtracted by the first subtractor 903 (a feedback signal and a multipath signal are removed). Signal coefficient) to generate a filter coefficient to be used by the first adaptive filtering unit 904 during the data period (1505).

Thereafter, the first adaptive filtering unit 904 subtracts the filter coefficients generated by the first and second filter coefficient generators 905 and 907 and the signal subtracted by the first subtractor 903 (a feedback signal and a multiplexer). A replica of a feedback signal and a multipath signal is generated based on the path signal is removed and fed back to the first subtractor 903 (1506).

As described above, the co-channel relay apparatus and method for improving feedback signal and multipath signal elimination capability are suitable for broadcasting (ATSC, DVB, DMB, ISDB-T, etc.) and communication (Wibro, CDMA, etc.). However, the present invention is not limited to this, but it can be applied in an environment where a relay device is required for general single frequency network configuration.

On the other hand, the method of the present invention as described above can be written in a computer program. And the code and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the written program is stored in a computer-readable recording medium (information storage medium), and read and executed by a computer to implement the method of the present invention. The recording medium may include any type of computer readable recording medium.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The present invention can be used for co-channel relay system.

1 is a configuration diagram of an embodiment of a conventional relay system;

2 is a configuration diagram of another embodiment of a conventional relay system;

3 is a configuration diagram of an embodiment of a conventional RF amplified co-channel repeater;

4 is a configuration diagram of an embodiment of a conventional IF conversion co-channel repeater;

5 is a configuration diagram of an embodiment of a conventional SAW filter co-channel repeater;

6 is a configuration diagram of an exemplary demodulation type co-channel relay apparatus having a feedback signal removing function;

7 is a detailed configuration diagram of an embodiment of the demodulation type co-channel relay of FIG. 6;

8 is a detailed configuration diagram of an embodiment of the filter coefficient generator of FIG. 7;

9 is a configuration diagram of an embodiment of a co-channel relay apparatus according to the present invention;

10 is a detailed configuration diagram of an embodiment of the same channel relay apparatus of FIG. 9;

11 is a view illustrating a principle of estimating an error of a filter coefficient of the first adaptive filtering unit in the second filter coefficient generator and updating the filter coefficient of the first adaptive filtering unit based on the estimated error;

12 is a structural diagram of an embodiment of a time domain pilot stored in a time domain pilot storage unit;

13 is a detailed structural diagram of an embodiment of a time domain signal determination unit;

14 is a flowchart illustrating an embodiment of an on-channel relay method according to the present invention;

FIG. 15 is a detailed flowchart of an embodiment of a replica generating process of FIG. 14.

* Explanation of symbols for the main parts of the drawings

901: receiving antenna 902: RF receiving unit

903: First subtraction unit 904: First adaptive filtering unit

905: first filter coefficient generation unit 906: time domain pilot storage unit

907: Second filter coefficient generator 908: Time domain signal determination unit

909 and 910: pilot section and data section switching unit

911: RF transmitter 912: transmit antenna

913: replica generator

Claims (13)

In the same channel repeater, Receiving means for receiving a signal; First subtracting means for subtracting a 'replica of a feedback signal and a multipath signal' from the signal from the receiving means; A replica generation means for generating a filter coefficient in a pilot section and a data section, respectively, and generating the 'replica of the feedback signal and the multipath signal' using the generated filter coefficient and feeding it back to the first subtracting means; And Transmitting means for transmitting an output signal from the first subtracting means Co-channel repeater comprising a. The method of claim 1, The replica generating means, Selecting means for discriminating and selecting the pilot section and the data section; First filter coefficient processing means for generating a filter coefficient using a time domain pilot during the pilot period; Second filter coefficient processing means for generating a filter coefficient using a time domain signal during the data section; And Generating a 'replica of the feedback signal and the multipath signal' based on the filter coefficients from the first and second filter coefficient processing means and the signal subtracted by the first subtracting means. First adaptive filtering means for feeding back to the first subtracting means Co-channel repeater comprising a. The method of claim 2, The second filter coefficient processing means, Time domain signal determining means for generating a time domain signal determined based on the signal subtracted by the first subtracting means; And Second filter coefficient generating means for generating a filter coefficient to be used in said first adaptive filtering means during said data interval based on the time domain signal from said time domain signal determining means and a signal subtracted by said first subtracting means; Co-channel repeater comprising a. The method of claim 3, wherein The second filter coefficient generating means, Based on the time-domain signal from the time-domain signal determining means and the signal subtracted by the first subtracting means, estimates an error that the filter coefficient of the first adaptive filtering means has during the data period, And updating (compensating) the filter coefficient of the first adaptive filtering means on the basis of the same. The method of claim 4, wherein The second filter coefficient generating means, Second subtracting means for subtracting a 'replica of the residual feedback signal and the remaining multipath signal' included in the output signal from the first subtracting means in the data section; Based on the output signal from the second subtracting means and the determined time domain signal from the time domain signal determining means, the error of the filter coefficient of the first adaptive filtering means is estimated, and the first adaptive filtering means and the first Filter coefficient error estimation means for generating a filter coefficient of the adaptive filtering means; And The first for generating the 'replication of the residual feedback signal and the residual multipath signal' based on the filter coefficient from the filter coefficient error estimation means and the output signal from the second subtracting means and feeding it back to the second subtracting means. 2 adaptive filtering means Co-channel repeater comprising a. The method of claim 3, wherein The time domain signal determining means, A Fourier transform unit for converting a time domain signal corresponding to one orthogonal frequency division multiplexing (OFDM) symbol into an frequency domain signal in the output signal from the first subtraction unit; A DQPSK demodulator for demodulating the frequency domain signal converted by the Fourier transform unit (DQPSK); A hard decision unit for determining a frequency domain signal demodulated by the DQPSK in the DQPSK demodulator; A DQPSK modulator for DQPSK modulating the frequency domain signal determined by the hard decision unit; And An inverse Fourier transformer for converting the DQPSK modulated frequency domain signal into a time domain signal and outputting the determined time domain signal Co-channel repeater comprising a. The method according to any one of claims 2 to 6, The first filter coefficient processing means, Time domain pilot storage means for storing time domain pilot signals; And A first filter for generating a filter coefficient to be used in the first adaptive filtering means during the pilot period based on a time-domain pilot signal stored in the time-domain pilot storage means and a signal subtracted by the first subtracting means Coefficient generation means Co-channel repeater comprising a. In the same channel relay method, Receiving a signal; A first subtraction step of subtracting a 'replica of a feedback signal and a multipath signal' from the received signal; A replica generation step of generating a filter coefficient in a pilot section and a data section, and generating the 'replica of the feedback signal and the multipath signal' using the generated filter coefficient and feeding back to the first subtraction step; And Transmitting a signal whose channel distortion is compensated by removing the feedback signal and the multipath signal Co-channel relay method comprising a. The method of claim 8, The replica generation step, Determining and selecting the pilot section and the data section; A first filter coefficient processing step of generating a filter coefficient using a time domain pilot during the pilot period; A second filter coefficient processing step of generating a filter coefficient using a time domain signal during the data section; And The replica of the feedback signal and the multipath signal are generated based on the filter coefficients generated in the first and second filter coefficient processing steps and the signal subtracted in the first subtraction step. First adaptive filtering step feeding back to the first subtraction step Co-channel relay method comprising a. The method of claim 9, The second filter coefficient processing step, Generating a time domain signal determined based on the signal subtracted in the first subtraction step; And A second filter coefficient generation step of generating a filter coefficient to be used in the first adaptive filtering step during the data period based on the determined time-domain signal and the signal subtracted in the first subtraction step Co-channel relay method comprising a. The method of claim 10, The second filter coefficient generation step, An error having a filter coefficient of the first adaptive filtering step during the data period is estimated based on the determined time-domain signal and the signal subtracted in the first subtracting step, and based on the estimated error, the first adaptive An on-channel relay method comprising updating (compensating) a filter coefficient of a filtering step. The method of claim 11, The second filter coefficient generation step, A second subtraction step of subtracting a replica of the residual feedback signal and the residual multipath signal included in the signal subtracted in the first subtraction step during the data period; The error of the filter coefficient of the first adaptive filtering step is estimated based on the signal subtracted in the second subtraction step and the determined time domain signal, and used in the first adaptive filtering step and the second adaptive filtering step. A filter coefficient error estimation step of generating a filter coefficient; And Generating a 'replica of the residual feedback signal and the residual multipath signal' based on the filter coefficient generated in the filter coefficient error estimating step and the signal subtracted in the second subtracting step and feeding back to the second subtracting step; 2 Adaptive Filtering Steps Co-channel relay method comprising a. The method according to any one of claims 9 to 12, The first filter coefficient processing step, Based on the pre-stored time-domain pilot signal and the signal subtracted in the first subtracting step, the filter coefficient to be used in the first adaptive filtering step during the pilot period is obtained. On-channel relay method, characterized in that for generating.

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