KR20080069753A - Apparatus and method for cooperative transmission in multiple antenna system - Google Patents

Abstract

An apparatus and a method for relaying signals for cooperative transmission in a multiple antenna system are provided to make it unnecessary for a terminal to know definite downlink CSI(Channel State Information) and to simplify a structure of a receiving unit in the terminal. An apparatus for relaying signals for cooperative transmission includes a detector(301), a demodulator(303), a decoder(305), a controller(307), a channel estimator(309), a channel gain comparator(311), an encoder(313), a modulator(315), a multiplexor(317), a reference data generator(319) and a power restricting unit(321). The detector detects a sounding signal or a pilot signal from multiple antennas of the terminal, and outputs the detected signal to the channel estimator. The demodulator demodulates the signal, outputted by the detector, according to a modulation scheme of a transmitter and outputs coded data. The decoder receives the coded data from the demodulator, decodes the coded data into original data, and outputs the original data to the controller. The channel estimator estimates channels among the multiple antennas by using the detected sounding signal or pilot signal, and provides the estimated channel value for the channel gain comparator and the multiplexor. The channel gain comparator calculates a channel gain by referring to the provided estimated channel value, compares the calculated channel gain with a threshold, and determines whether a cooperative communication is performed together with the terminal. The controller reports the calculated channel gain to a base station in case that the cooperative communication has to be performed. The power restricting unit calculates a power restriction constant by using the estimated channel value, and provides the power restriction constant for the multiplexor.

Description

Relay apparatus and method for cooperative transmission in a multi-antenna system {APPARATUS AND METHOD FOR COOPERATIVE TRANSMISSION IN MULTIPLE ANTENNA SYSTEM}

1 is a configuration diagram of the mobile communication system assisted by a repeater;

2 is a diagram illustrating a frame format for data relay;

3 is a block diagram of a repeater device for performing maximum ratio transmission in a multi-antenna system according to an embodiment of the present invention;

4 is a block diagram of a terminal device for relay communication using a maximum ratio transmission in a multiple antenna system according to an embodiment of the present invention;

5 is a block diagram of a base station apparatus for relay communication using maximum ratio transmission in a multi-antenna system according to an exemplary embodiment of the present invention;

6 is a flowchart illustrating operation of a repeater using maximum ratio transmission in a multi-antenna system according to a first embodiment of the present invention;

7 is a flowchart illustrating a terminal operation using maximum ratio transmission in a multi-antenna system according to a first embodiment of the present invention;

8 is a flowchart illustrating operation of a base station using maximum ratio transmission in a multi-antenna system according to the first embodiment of the present invention;

9 is a flowchart illustrating operation of a repeater using maximum ratio transmission in a multi-antenna system according to a second embodiment of the present invention;

10 is a flowchart illustrating operation of a repeater using maximum ratio transmission in a multi-antenna system according to a third embodiment of the present invention;

11 is a flowchart illustrating an operation of a terminal using a maximum ratio transmission in a multi-antenna system according to a third embodiment of the present invention;

12 is a flowchart illustrating operation of a repeater using maximum ratio transmission in a multi-antenna system according to a fourth embodiment of the present invention;

13 is a flowchart illustrating operation of a base station using maximum ratio transmission in a multi-antenna system according to a fourth embodiment of the present invention.

The present invention relates to a relay apparatus and method for cooperative transmission in a multi-antenna system, and more particularly to a relay apparatus and method for performing cooperative transmission using the maximum ratio transmission in the multi-antenna system.

A relay station is a technology currently used to solve the shadow area in the existing mobile communication system. In particular, the introduction of intelligent repeaters in next-generation mobile communication systems will be more actively used to expand coverage and improve data throughput while reducing the cost of base station expansion and maintenance of backhaul communication networks. Here, a configuration diagram of the mobile communication system assisted by the repeater will be described with reference to FIG. 1. In the mobile communication system assisted by the repeater 110, the Internet backbone 140 is connected to the mobile communication network 130 to provide an Internet service. The mobile communication network 130 is connected to a plurality of base stations 101 and 102 to control the base stations 101 and 102 and switch switching. One base station 101 is in communication with a plurality of repeaters (111 ~ 115), the terminal 125. The base station 101 in communication with the repeaters 111, 112, 113, 114, 115 is defined as the parent base station of the repeaters 111, 112, 113, 114, 115. On the other hand, the repeaters 111, 112, 113, 114, and 115 are defined as child repeaters of the base station 101. One repeater 120 communicates with a plurality of terminals 120. The repeaters 111, 112, 113, 114, and 115 communicating with the terminals 121, 122, and 123 are defined as upper relays of the terminals 121, 122, and 123. On the other hand, the terminals 121, 122, 123 are lower terminals of the repeater. The terminal 125 directly communicating with the base station 101 without the relays 110 is defined as a legacy terminal of the base station 101. In the downlink (base station-> relay-> terminal), the repeaters 110 receive a message from the base station 101, and better relay to mobile to the lower terminals 120 of the repeater. rink to resend the message. In the uplink (terminal-> relay-> base station), the repeaters 110 receive a message from the lower terminals 120 and retransmit to the upper base station 101 of the repeaters 110. The retransmission is performed by an amplify-and-forward or a decode-and-forward. In the post-amplification transmission scheme, the repeaters simply amplify the received signal together with the amplified additional white noise and transmit it to the terminals. In the post-decoding transmission scheme, the repeaters decode and re-encode the message before forwarding to the destination terminals, and then reschedules the transmission. Although the post-amplification delivery scheme can simplify the repeater structure, the post-decoding delivery scheme is better in terms of robustness and efficiency.

Time division duplex repeaters that support mobile communication systems operate in half duplex mode. That is, the system alternately transmits the downlink frame and the uplink frame. Referring to FIG. 2 illustrating a transmission frame structure, the transmission frame structure includes a downlink frame 210 from a base station to a repeater, a downlink frame 212 from a repeater to a terminal, and an uplink frame 214 from a terminal to a repeater. In the repeater, the uplink frame 216 of the base station is divided. The downlink frame 210 from the base station to the repeater is composed of a base station preamble symbol 200, control overhead 202, and downlink data symbols 206. The downlink frame 212 from the repeater to the terminal consists of a repeater preamble symbol 200, control overhead 202, and downlink data symbols 206. The uplink frame 214 from the terminal to the repeater includes a postamble or sounding zone 208 and uplink data symbols 206. The uplink frame 216 of the base station in the repeater consists of uplink data symbols 206.

For example, the base station transmits data to the lower relays and the legacy terminals through the downlink frame 210 from the base station to the repeater. In this case, the repeaters do not transmit data to the base station or the terminal. The repeater transfers the data received from the base station to the lower terminal through a downlink frame 212 from the repeater to the terminal. The lower terminals transmit data to the repeater through the uplink frame 214 from the terminal to the repeater, and the legacy terminals transmit to the base station. In this case, the repeaters do not transmit data to the base station or the terminal. The repeaters forward the received messages from the repeater to the higher base station via the uplink frame 216 of the base station.

In the conventional case, in a multi-antenna system, when a repeater performs relay to a corresponding terminal by selection of a base station or a terminal, the terminal obtains a reception diversity gain in a maximum ratio combining (MRC) scheme. However, when the MRC technique and the space-time block code (STBC) technique are combined (STBC-MRC), a bit error ratio (BER) performance is deteriorated.

Accordingly, an object of the present invention is to provide a relay apparatus and method for improving a bit error rate in a space-time block code method.

Accordingly, an object of the present invention is to provide a relay apparatus and method for providing a transmit diversity gain through cooperative transmission of repeaters in a multi-antenna system.

Another object of the present invention is to provide an apparatus and method for performing cooperative transmission using the maximum ratio transmission in a multi-antenna system.

It is still another object of the present invention to provide a relay apparatus and method for improving bit error rate by performing a maximum ratio transmission that compensates for channel fading in a multi-antenna system.

According to a first aspect of the present invention for achieving the above objects, in a relay apparatus for performing a maximum ratio transmission cooperatively in a multi-antenna system, receiving a sounding signal or a pilot signal from a terminal to calculate a channel estimation value A channel gain comparison unit for comparing the channel estimation value with the channel gain threshold value and determining whether to perform cooperative communication with the terminal, and reporting the channel estimation value to the base station during the cooperative communication. And calculating a power limit constant value for transmission, and generating relay data using the power limit constant value and the channel estimation value.

According to a second aspect of the present invention for achieving the above objects, in a terminal apparatus for performing the maximum ratio transmission cooperatively in a multi-antenna system, reference data for generating a sounding signal or a pilot signal to be transmitted to the repeaters A generating unit, a detecting unit for receiving pilot data from repeaters performing cooperative communication with terminals of the repeaters, a partial channel estimator for calculating partial channel state information using the pilot data, respectively, and the partial channel And a demodulator for decoding the data using the state information.

According to a third aspect of the present invention for achieving the above objects, in a base station that performs the maximum ratio transmission cooperatively in a multi-antenna system, the repeater and the multi-antennas of the terminal from the repeater performing cooperative transmission with the terminal A control unit for receiving a channel estimate value between the power limiter for calculating a power limit constant value for maximum ratio transmission using the channel estimate values of the repeaters, and the power limit constant values for the repeaters, respectively. It characterized in that it comprises an RF processor for transmitting.

According to a fourth aspect of the present invention for achieving the above objects, in a relay apparatus for cooperatively performing a maximum ratio transmission in a multi-antenna system, receiving a sounding signal or a pilot signal from a terminal to calculate a channel estimation value A channel gain comparison unit for determining whether to perform cooperative communication with the terminal by comparing the channel estimation value with the channel estimation value and the channel gain threshold value, and performing the maximum ratio transmission using the channel estimation value during the cooperative communication. And a power limiting unit for calculating a power limiting constant value, and a multiplexer for generating relay data using the power limiting constant value and the channel estimation value.

According to a fifth aspect of the present invention for achieving the above objects, a terminal for performing a maximum ratio transmission cooperatively in a multi-antenna system, the reference data generating unit for generating a sounding signal or a pilot signal with repeaters; And a partial channel estimator for receiving decoding information necessary for decoding relay data from repeaters performing cooperative communication with a terminal among the repeaters, and a demodulator for decoding using the decoding information.

According to a sixth aspect of the present invention for achieving the above objects, in a terminal for performing the maximum ratio transmission cooperatively in a multi-antenna system, a reference data generation unit for generating a sounding signal or a pilot signal with repeaters; And a partial channel estimator for receiving decoding information necessary for decoding relay data from repeaters performing cooperative communication with a terminal among the repeaters, and a demodulator for decoding using the decoding information.

According to a seventh aspect of the present invention for achieving the above objects, in a relay method for cooperatively performing a maximum ratio transmission in a multi-antenna system, receiving a sounding signal or a pilot signal from a terminal and calculating a channel estimation value And determining whether to perform cooperative communication with the terminal by comparing the channel estimation value and the channel gain threshold value, and reporting the channel estimation value to the base station during the cooperative communication. Receiving a limit constant value, and generating relay data using the power limit constant value and the channel estimation value.

According to an eighth aspect of the present invention for achieving the above object, in the relay method for cooperatively performing the maximum ratio transmission in a multi-antenna system, transmitting a sounding signal or a pilot signal to the repeaters, Receiving pilot data from repeaters performing cooperative communication with the terminal among the repeaters, calculating partial channel state information using the pilot data, and using the partial channel state information It includes a process of decoding.

According to a ninth aspect of the present invention for achieving the above objects, in a relay method for cooperatively performing a maximum ratio transmission in a multi-antenna system, a channel estimation value between repeaters and multiple antennas of a terminal is determined. Receiving, calculating power limit constants for maximum ratio transmission using the channel estimation values of the repeaters, and transmitting power limit constant values to the repeaters, respectively. It is done.

According to a tenth aspect of the present invention for achieving the above objects, in the relay method for performing the maximum ratio transmission cooperatively in a multi-antenna system, receiving a sounding signal or a pilot signal from the terminal to calculate a channel estimation value And determining whether to perform cooperative communication with the terminal by comparing the channel estimation value and the channel gain threshold value, and during the cooperative communication, a power limit constant value for maximum ratio transmission using the channel estimation value. And calculating the relay data using the power limit constant value and the channel estimation value.

According to an eleventh aspect of the present invention for achieving the above object, a relay method for cooperatively performing the maximum ratio transmission in a multi-antenna system, the step of transmitting a sounding signal or a pilot signal to the repeaters, and Receiving decoding information necessary for decoding the relay data from the repeaters performing cooperative communication with the terminal among the repeaters; And decoding using the information.

According to a twelfth aspect of the present invention for achieving the above object, in the relay method for cooperatively performing the maximum ratio transmission in a multi-antenna system, receiving information on whether to cooperative transmission with the terminal from the repeaters And a counter for counting the number of repeaters performing cooperative transmission with the terminal using the information, and transmitting information on the total number of repeaters performing cooperative transmission with the terminal to the terminal. do.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, an apparatus and method for performing cooperative transmission using Maximum Ratio Transmission (MRT) in a multi-antenna system will be described. Here, four power limitation scenarios for performing the maximum ratio transmission are assumed. The average total transmit power from all the first repeaters has a constant value and the case where the base station calculates the power limit constant value is referred to as power limit scenario 1. The average total transmit power from all the second repeaters has a constant value and the case of calculating the power limit constant value at each repeater is called power limit scenario 2. The reception power of the third terminal has a constant value, and the case of calculating the power limit constant value regardless of the total number of repeaters in each of the repeaters is called a power limit scenario 3. The received power of the fourth terminal has a constant value, and the case of calculating the power limit constant value in consideration of the total number of repeaters in each repeater is referred to as power limit scenario 4.

6 to 8, the power limit scenario 2 is shown in FIG. 9, the power limit scenario 3 is shown in FIGS. 10 to 11, and the power limit scenario 4 is shown in FIG. 12 to 13 will be described.

개의 수신안테나를 가지는 단말로 구성된 다중안테나 시스템을 가정하여 설명하기로 한다.In the following description of FIGS. 5 to 13, one base station, L repeaters each having one antenna,

It will be described on the assumption of a multi-antenna system consisting of terminals having two receiving antennas.

3 is a block diagram of a repeater device for performing maximum ratio transmission in a multi-antenna system according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the repeater includes a detector 301, a demodulator 303, a decoder 305, a controller 307, a channel estimator 309, a channel gain comparator 311, an encoder 313, The modulator 315 includes a multiplexer 317, a reference data generator 319, and a power limiter 321.

The detector 301 detects a sounding signal or a pilot signal from the multiple antennas of the terminal and outputs the sounding signal or pilot signal to the channel estimator 309. In addition, the detector 301 converts a signal of a high frequency band from a base station into a baseband signal and outputs it.

The demodulator 303 demodulates a signal output from the detector 301 according to a modulation method of a transmitter and outputs coded data. The decoder 305 receives the encoded data from the demodulator 303 and decodes the encoded data into original information data and outputs the encoded data to the controller 307.

를 상기 채널이득 비교부(311)와 상기 다중화기(319)로 제공한다. 만약, 중계기에서 전력제한 상수 값을 계산하는 경우라면 또한 상기 채널 추정기(309)는 추정한 채널 값

를 상기 전력제한부(311)로 출력해야 한다. 여기서, 상기

은

으로 표현된다. 상기

는 단말의 다중안테나 인덱스이고 상기

은 중계기의 인덱스이다.The channel estimator 309 estimates a channel between multiple antennas of the terminal using the sounding signal or the pilot signal detected by the detector 301, and estimates the estimated channel value.

Is provided to the channel gain comparator 311 and the multiplexer 319. If the repeater calculates a power limit constant value, the channel estimator 309 also estimates the estimated channel value.

It should be output to the power limiting unit 311. Where

silver

It is expressed as remind

Is the multi-antenna index of the terminal

Is the index of the repeater.

를 참조하여 채널이득을 계산하고, 상기 계산된 채널이득(

)과 채널이득 임계값과 비교하여 단말과 협력통신(cooperation communication)을 할지 하지 않을지 결정하여 상기 제어부(307)로 알려준다. 즉, 상기 계산된 채널이득이 상기 임계값보다 크면 상기 제어부(307)는 상기 기지국과 상기 단말 사이에서 협력통신을 제어하고, 반면 상기 계산된 채널이득이 상기 임계값보다 작으면 상기 제어부(307)는 상기 기지국과 상기 단말 사이에서 협력통신에서 빠진다.The channel gain comparison unit 311 is a channel estimation value provided from the channel estimator 309

Calculate the channel gain with reference to the calculated channel gain (

) And whether or not to perform cooperation communication with the terminal in comparison with the channel gain threshold value and inform the control unit 307. That is, if the calculated channel gain is greater than the threshold, the controller 307 controls cooperative communication between the base station and the terminal, whereas if the calculated channel gain is less than the threshold, the controller 307 Is omitted in the cooperative communication between the base station and the terminal.

을 기지국으로 보고한다. 또한, 상기 제어부(307)는 전력제한 상수 값

을 수신부를 통해 상기 기지국으로부터 수신한 후 상기 전력제한부(321)로 출력한다. 상기 기지국에서 상기 전력제한 상수 값을 구하는 경우 상기 제어부(307)가 동작하는 상황이다. 만약, 중계기 자체에서 전력제한 상수 값을 계산하는 경우라면 상기 제어부(307)는 상기

을 기지국으로 보고하지 않고 상기 전력제한부(321)로 상기 채널추정 값

을 출력한다.The controller 307 calculates the calculated channel gain provided from the channel gain comparison unit 311 when the cooperative communication is to be performed.

Report to the base station. In addition, the control unit 307 is a power limit constant value

After receiving from the base station through the receiving unit and outputs to the power limiting unit 321. The control unit 307 operates when the base station obtains the power limit constant value. If, in the case of calculating the power limit constant value in the repeater itself, the control unit 307 is

The channel estimation value to the power limiting unit 321 without reporting to the base station

Outputs

을 이용하여 전력제한 상수 값

을 계산하여 상기 다중화기(317)로 제공한다. 여기서, 상기 전력제한 상수 값

은 전력제한 시나리오 2, 3, 4에 따라 하기 <수학식 1>, <수학식 2>, <수학식 3>으로 계산된다.The power limiting unit 323 is a channel estimation value from the control unit 307

Power limit constant using

Is calculated and provided to the multiplexer 317. Here, the power limit constant value

Is calculated by Equations 1, 2, and 3 according to the power limit scenarios 2, 3, and 4.

는

중계기의 전력제한 상수 값이고

은

중계기와 단말의

수신안테나 사이의 채널 추정 값이고 상기

은 단말의 수신안테나 개수이고 상기

는

중계기의 전체 채널 추정 값이다. 상기

는

으로 표현된다.Where

Is

The power limit constant of the repeater

silver

Of repeater and terminal

The channel estimate between the receiving antennas

Is the number of reception antennas of the terminal and

Is

The total channel estimate of the repeater. remind

Is

It is expressed as

는

중계기의 전력제한 상수 값이고

은

중계기와 단말의

수신안테나 사이의 채널 추정 값이고 상기

은 단말의 수신안테나 개수이고 상기

는

중계기의 전체 채널 추정 값이다.Where

Is

The power limit constant of the repeater

silver

Of repeater and terminal

The channel estimate between the receiving antennas

Is the number of reception antennas of the terminal and

Is

The total channel estimate of the repeater.

는

중계기의 전력제한 상수 값이고

은

중계기와 단말의

수신안테나 사이의 채널 추정 값이고 상기

은 단말의 수신안테나 개수이고 상기

는

중계기의 전체 채널 추정 값이고

은 협력통신을 하는 총 중계기 개수이다.Where

Is

The power limit constant of the repeater

silver

Of repeater and terminal

The channel estimate between the receiving antennas

Is the number of reception antennas of the terminal and

Is

The total channel estimate of the repeater

Is the total number of repeaters with cooperative communication.

In addition, the controller 307 notifies the terminal or the base station whether or not the repeater communication in accordance with the power limitation scenario. The controller 307 outputs the decoded information data from the decoder 305 to the encoder 313.

The encoder 313 receives the information data from the controller 307 and encodes the coded data at the corresponding code rate, and outputs coded bits or symbols to the modulator 315.

The modulator 317 outputs complex symbol data obtained by modulating the data data encoded by the encoder 315 to the multiplexer 317. Here, when PSK modulation is performed in the modulator 317, it is not necessary to transmit pilot data from the terminal.

와 상기 전력제한부(323)으로부터 제공되는 상기 전력제한 상수 값

을 이용하여 상기 변조기(317)로부터 출력되는 상기 복소심벌 데이터들을 시공간블록 부호를 수행한다. 출력 데이터는 여기서, 생성된 데이터는 상기 <수학식 4>로 표현된다.The multiplexer 319 is a channel estimator value provided from the channel estimator 309.

And the power limit constant value provided from the power limit unit 323.

Space-time block code is performed on the complex symbol data output from the modulator 317 using. The output data is here, and the generated data is represented by Equation 4 above.

은

중계기에서 단말로 전송되는 전송벡터이고, 상기

은

번째 중계기의 전력제한 상수 값이고, 상기

는 중계기와 단말의 다중 안테나 사이의 채널행렬의 전치행렬로 상기

으로 표현되고, 상기

는 STBC(Space-Time Block Code) 인코딩된 변조신호이다. 상기

는 하기 <수학식 5>로 표현된다.Where

silver

A transmission vector transmitted from the repeater to the terminal,

silver

Power limit constant value of the first repeater,

Is the transpose of the channel matrix between the repeater and the multiple antennas of the terminal.

Represented by the above

Is a space-time block code (STBC) encoded modulated signal. remind

Is expressed by Equation 5 below.

는

번째 변조된 심벌이고, 상기

는 상기

의 공액 복소 심벌이고, 상기

는 STBC 구성 행렬이다.Where

Is

The modulated symbol, and

Above

Is a conjugated complex symbol of

Is the STBC composition matrix.

The reference data generator 319 generates a reference signal (pilot signal or preamble signal) and outputs it to the multiplexer 317 so that the terminal can decode the data. For example, referring to FIG. 2, a reference signal is transmitted using a repeater preamble of the terminal white frame 212 from the repeater in a frame structure.

4 is a block diagram of a terminal device for relay communication using maximum ratio transmission in a multi-antenna system according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the terminal includes a transmitter and a receiver, and the transmitter includes a MIMO detector 401, a demodulator 403, a decoder 405, a partial channel estimator 407, and a counter 409. The receiver includes a multiplexer 411, a modulator 413, an encoder 415, and a reference data generator 417.

The MIMO detection unit 401 detects data signals transmitted from repeaters and base stations through multiple antennas. In addition, the MIMO detection unit 401 periodically detects a pilot signal from the repeaters.

The demodulator 403 demodulates a pilot signal output from the MIMO detector 401 and outputs the demodulated signal to the partial channel estimator 407. In addition, the demodulator 403 receives the partial channel state information value from the partial channel estimator 407 and demodulates the data signal output from the MIMO detector 401 and outputs the demodulated data signal to the decoder 405.

는 검출되어 디코딩된 심벌이고, 상기

는

으로 행렬 트레이스 연산(matrix trace operation)이고, 상기

는 정의된 데이터 심벌이고, 상기

은

번째 중계기의 전력제한 값이고, 상기

은

번째 중계기에서 단말의

안테나와의 채널추정 값이고. 상기

은 협력통신을 수행하는 중계기의 수이고, 상기

은 단말의 수신안테나 수이고, 상기

은 부분 채널상태정보 값이다. 여기서, 상기

이 조절됨으로써 상기 <수학식 6>의

은 하기 <수학식 7>로 대체할 수 있다.Where

Is a detected and decoded symbol, and

Is

Matrix trace operation,

Is a defined data symbol, and

silver

Power limit value of the first repeater,

silver

Of the terminal at the first repeater

Channel estimate with the antenna. remind

Is the number of repeaters performing cooperative communication, and

Is the number of reception antennas of the terminal,

Is the partial channel status information value. Where

By adjusting the above Equation 6

May be replaced by Equation 7 below.

The decoder 405 receives the demodulated signal from the demodulator 403 and performs decoding.

The partial channel estimator 407 calculates and provides a partial channel state information value to the demodulator 403 using the detected and demodulated pilot symbols. The partial channel state information value is calculated by Equation 6 below.

는 부분적인 CSI 값이고, 상기

는 변조된 심벌 수이고, 상기

는 상기 중계기로부터 수신한 파일럿 블록 데이터이고, 상기

는 정의된 파일럿 블록 데이터이다.Where

Is a partial CSI value,

Is the number of modulated symbols, and

Is pilot block data received from the repeater, and

Is defined pilot block data.

)를 카운트하여 복조시 상기 복조기(403)로 상기 중계기 수(

) 을 제공한다.The counter unit 408 receives information on whether or not to perform cooperative communication from the repeater and the number of repeaters participating in the cooperative communication (

) And the number of repeaters to the demodulator 403 during demodulation.

).

The encoder 415 outputs input information data as encoded data according to a corresponding code rate. The modulator 413 modulates the coded data output from the encoder 413 in a corresponding modulation scheme and outputs the complex symbol.

The multiplexer 411 encodes a fast data transmission through a spatial multiplexing technique or transmits the same data from multiple transmit antennas to obtain a spatial diversity gain.

The reference data generator 417 generates pilot data or preamble data and outputs the pilot data or preamble data to the multiplexer 409 so that a relay station or a base station can perform channel estimation.

5 is a block diagram of a base station apparatus for receiving received data using maximum ratio transmission in a multi-antenna system according to an exemplary embodiment of the present invention.

Referring to FIG. 5, the base station includes an RF processor 501, a demodulator 503, a decoder 505, a controller 507, an encoder 511, a modulator 513, and an RF processor 515. .

The RF processor 501 receives a data signal from a repeater or a terminal, converts the data signal to a baseband, and outputs the data signal to the demodulator 503.

The demodulator 503 demodulates symbols according to a modulation scheme of a transmitter and outputs encoded data. The decoder 505 decodes the coded data from the demodulator 503 according to the code method of the transmitter to restore the original information data.

The controller 500 is responsible for the overall control of the base station, and further includes a power limiting unit 509 and a counter 511 according to the present invention.

The power limiting unit 509 calculates a power limit constant value using the channel gain value from the repeater and transmits it to the repeater. The power limit constant value is obtained by Equation 4 below.

는

중계기의 전력제한 상수 값이고

은

중계기와 단말의

수신안테나 사이의 채널 추정 값이고 상기

은 단말의 수신안테나 개수이고 상기

는

중계기의 전체 채널 추정 값이다.Where

Is

The power limit constant of the repeater

silver

Of repeater and terminal

The channel estimate between the receiving antennas

Is the number of reception antennas of the terminal and

Is

The total channel estimate of the repeater.

The counter 511 calculates the total number of repeaters to perform cooperative communication by counting with reference to the information on the cooperative communication with the terminal from the repeaters according to the power limit scenario 4.

The encoder 511 receives data from the controller 507 and encodes the data at a code rate, and outputs coded bits or symbols to the modulator 513.

The modulator 515 modulates the data symbols encoded from the encoder 513 in a corresponding modulation scheme and outputs complex symbols to the RF processor 517.

The RF processor 517 includes components such as a filter and a preprocessor. The RF processor 517 RF-processes a signal output from a modulator to be actually transmitted, and then transmits the RF signal to a wireless channel through a transmission antenna.

6 is a flowchart illustrating a repeater operation using maximum ratio transmission in a multi-antenna system according to the first embodiment of the present invention.

Referring to FIG. 6, first, a repeater periodically receives a sounding signal or a pilot signal from the terminal for channel estimation between the repeater and multiple antennas of the terminal in step 600. According to an implementation, the repeater may be received by requesting a sounding signal or a pilot signal to the terminal.

)으로부터 채널상태정보(Channel State Information:이하 "CSI"라 칭함)를 계산한다. 여기서, 상기 CSI는 채널이득을 의미한다.In step 602, the repeater repeats the channel estimation value (

Channel State Information (hereinafter referred to as "CSI") is calculated. Here, the CSI means channel gain.

)을 보고한다. 여기서, 상기 채널이득이 상기 임계값을 비교하는 것은 상기 중계기가 상기 기지국과 상기 단말 사이에서 협력통신을 할지 안할지 여부를 결정하기 위함이다. 다시 말해, 만일 계산된 채널이득이 상기 임계값보다 더 크면, 상기 중계기는 상기 기지국과 상기 단말 사이에서 상기 협력통신을 수행한다. 만약 계산된 채널이득이 상기 임계값보다 작으면, 상기 중계기는 상기 협력통신에서 빠진다.Thereafter, the repeater compares the channel gain calculated in step 604 with the channel gain threshold value, and when the channel gain is greater than the threshold value, the repeater moves to step 606 to transmit the channel gain value to the base station.

). Here, the channel gain compares the threshold value to determine whether the repeater performs cooperative communication between the base station and the terminal. In other words, if the calculated channel gain is greater than the threshold, the repeater performs the cooperative communication between the base station and the terminal. If the calculated channel gain is less than the threshold, the repeater is dropped from the cooperative communication.

)을 수신한다.Subsequently, the repeater repeats the power limit constant value from the base station in order to relay the data at the maximum ratio transmission in step 608.

).

In step 610, the repeater decodes the data to be relayed from the base station to the terminal.

Thereafter, the repeater periodically transmits pilot data to the terminal through downlink in order to enable the terminal to decode the relay data in step 612. According to a system implementation, the repeater may transmit the pilot data at the request of the terminal.

) 값과 상기 채널추정 값(

)을 이용하여 상기 단말로 중계할 데이터를 생성한 후, 상기 중계기는 생성한 데이터를 상기 단말로 중계한다. 여기서, 상기 생성된 데이터는 상기 <수학식 4>로 표현된다.Thereafter, the repeater receives the power limit constant 614 received from the base station.

) And the channel estimate (

After generating the data to be relayed to the terminal using), the repeater relays the generated data to the terminal. Here, the generated data is represented by Equation 4.

The repeater then terminates the relay procedure.

7 is a flowchart illustrating a terminal operation using maximum ratio transmission in a multi-antenna system according to the first embodiment of the present invention.

Referring to FIG. 7, first of all, the terminal 700 periodically transmits a sounding signal or a pilot signal to the repeater so that the repeater can perform channel estimation. In some cases, the sounding signal or the pilot signal may be transmitted at the request of a base station or a repeater.

In step 702, the terminal receives pilot data from the repeater to calculate partial channel state information necessary for decoding.

Thereafter, the terminal calculates the partial channel state information value for decoding using the pilot data received in step 704. The partial channel state information value is represented by Equation (7).

Thereafter, the terminal decodes the data received from the repeater using the partial channel state information calculated in step 706. The decoding is performed by Equation 6.

Thereafter, the terminal terminates the relay procedure.

8 is a flowchart illustrating an operation of a base station using maximum ratio transmission in a multi-antenna system according to the first embodiment of the present invention.

값을 수신한다.Referring to FIG. 8, first, the base station estimates a channel between the repeaters reported from the repeaters and the multiple antennas of the terminal in step 800.

Receive a value.

을 이용하여 전력제한 상수 값을 계산한다. 여기서 상기 전력제한 상수 값은 상기 <수학식 1>로 표현된다.Then, the base station is reported in each of the repeaters in step 802

Calculate the power limit constant using. Herein, the power limit constant value is represented by Equation (1).

)을 상기 중계기들로 전송한다.Thereafter, the base station determines the power limit constant value calculated in step 804.

) To the repeaters.

Thereafter, the base station terminates the relay procedure.

9 is a flowchart illustrating a repeater operation using the maximum ratio transmission in the multi-antenna system according to the second embodiment of the present invention.

Referring to FIG. 9, in step 900, the repeater periodically receives a sounding signal or a pilot signal from the terminal for channel estimation between the repeater and multiple antennas of the terminal. According to an implementation, the repeater may request the terminal to receive a sounding signal or a pilot signal.

)으로부터 CSI를 계산한다. 여기서, 상기 CSI는 채널이득을 의미한다.Subsequently, the repeater repeats the channel estimation value (

Calculate the CSI. Here, the CSI means channel gain.

Thereafter, the repeater compares the channel gain calculated in step 904 with the channel gain threshold value, and when the channel gain is greater than the threshold value, the repeater moves to step 906 to relay data from the base station to the terminal. Decode after receiving.

)을 계산한다. 상기 전력제한 상수 값은 상기 <수학식 2>로 계산된다.Subsequently, in step 908, the repeater uses the channel gain to limit data at the maximum ratio transmission.

Calculate The power limit constant value is calculated by Equation 2 above.

In step 910, the repeater periodically transmits pilot data to the terminal through downlink so that the terminal can decode the relay data. According to a system implementation, the repeater may transmit the pilot data at the request of the terminal.

) 값과 상기 채널추정 값을 이용하여 상기 단말로 중계할 데이터를 생성한 후, 상기 중계기는 생성한 데이터를 상기 단말로 중계한다. 여기서, 생성된 데이터는 상기 <수학식 4>로 표현된다.Thereafter, the repeater receives a power limit constant 912 received from the base station.

After generating the data to be relayed to the terminal using the value and the channel estimation value, the repeater relays the generated data to the terminal. Here, the generated data is represented by Equation 4 above.

The repeater then terminates the relay procedure.

Here, the operation of the base station according to the second embodiment is omitted since there is no additional function. Since the operation of the terminal according to the second embodiment is similar to that of FIG. 7, it will be referred to.

10 is a flowchart illustrating a repeater operation using the maximum ratio transmission in the multi-antenna system according to the third embodiment of the present invention.

Referring to FIG. 10, first, a repeater periodically receives a sounding signal or a pilot signal from the terminal for channel estimation between the repeater and multiple antennas of the terminal. According to an implementation, the repeater may request the terminal to receive a sounding signal or a pilot signal.

)으로부터 CSI를 계산한다. 여기서, 상기 CSI는 채널이득을 의미한다.Subsequently, the repeater repeats the channel estimation value (

Calculate the CSI. Here, the CSI means channel gain.

Thereafter, the repeater compares the channel gain calculated in step 1004 with the channel gain threshold value, and when the channel gain is greater than the threshold value, the repeater moves to step 906 to relay data from the base station to the terminal. Decode after receiving.

) 을 계산한다. 상기 전력제한 상수 값은 상기 <수학식 2> 로 계산된다.Subsequently, the repeater uses a power gain constant value using the channel gain to relay data at maximum ratio transmission in step 1008.

) Is calculated. The power limit constant value is calculated by Equation 2 above.

) 과 상기 채널추정 값

을 이용하여 상기 단말로 중계할 데이터를 생성한 후, 상기 중계기는 생성한 데이터를 상기 단말로 중계한다. 여기서, 생성된 데이터는 상기 <수학식 4>로 표현된다.Then, the repeater informs the terminal to perform cooperative communication with other repeaters in step 1010. The informing of whether the repeater is to perform cooperative communication with the terminal is to allow the terminal to decode the relay data. Thereafter, the repeater receives a power limit constant value 1010 received from the base station.

) And the channel estimation value

After generating data to be relayed to the terminal by using, the repeater relays the generated data to the terminal. Here, the generated data is represented by Equation 4 above.

The repeater then terminates the relay procedure.

11 is a flowchart illustrating an operation of a terminal using maximum ratio transmission in a multi-antenna system according to a third embodiment of the present invention.

Referring to FIG. 11, first, a terminal 1100 periodically transmits a sounding signal or a pilot signal to the repeater so that the repeaters can perform channel estimation. In some cases, the terminal may transmit the sounding signal or the pilot signal at the request of a base station or a repeater.

)를 계산한다.After that, the terminal counts whether the cooperative communication is performed from the repeaters in step 1102 and the total number of repeaters performing cooperative communication (

Calculate

를 이용하여 중계기로부터 수신한 데이터를 디코딩한다. 상기 디코딩은 상기 <수학식 6>으로 수행된다.Thereafter, the terminal in step 1104

Decode the data received from the repeater using. The decoding is performed by Equation 6.

Thereafter, the terminal terminates the relay procedure.

Here, the description of the operation of the base station according to the third embodiment will be omitted because there is no additional function in the prior art.

12 is a flowchart illustrating a repeater operation using the maximum ratio transmission in the multi-antenna system according to the fourth embodiment of the present invention.

Referring to FIG. 12, first, a repeater periodically receives a sounding signal or a pilot signal from the terminal for channel estimation between the repeater and multiple antennas of the terminal in step 1200. According to an implementation, the repeater may request the terminal to receive a sounding signal or a pilot signal.

)으로부터 CSI를 계산한다. 여기서, 상기 CSI는 채널이득을 의미한다.In step 1202, the repeater repeats the channel estimation value (

Calculate the CSI. Here, the CSI means channel gain.

Thereafter, the repeater compares the channel gain calculated in step 1204 with the channel gain threshold value, and when the channel gain is greater than the threshold value, the repeater moves to step 1206 to determine whether to perform cooperative communication with the base station. Inform.

)에 대한 정보를 수신한다.Subsequently, the repeater is the total number of repeaters performing cooperative communication from the base station in step 1208 (

Receive information about).

)과 상기

값을 이용하여 전력제한 상수(

) 값을 계산한다. 상기 전력제한 상수 값은 상기 <수학식 4> 으로 계산된다.Subsequently, the repeater repeats the channel gains in order to relay data at maximum ratio transmission in step 1210.

) And above

Power limit constant using

) Value is calculated. The power limit constant value is calculated by Equation 4 above.

In step 1212, the repeater decodes the data to be relayed from the base station to the terminal.

) 값과 상기 채널추정 값을 이용하여 상기 단말로 중계할 데이터를 생성한 후, 상기 중계기는 생성한 데이터를 상기 단말로 중계한다. 여기서, 생성된 데이터는 상기 <수학식 4>로 표현된다.Subsequently, the repeater receives a power limit constant (1214) received from the base station.

After generating the data to be relayed to the terminal using the value and the channel estimation value, the repeater relays the generated data to the terminal. Here, the generated data is represented by Equation 4 above.

The repeater then terminates the relay procedure.

13 is a flowchart illustrating an operation of a base station using maximum ratio transmission in a multiple antenna system according to a fourth embodiment of the present invention.

Referring to FIG. 13, the base station first receives information on whether to perform cooperative communication from a repeater in step 1300.

)를 계산한다.Afterwards, the base station counts the repeaters performing the cooperative communication in step 1302 and the total number of repeaters performing the cooperative communication (

Calculate

) 계산에 필요한

값을 상기 중계기로 전송한다.(상기 수학식 3 참조)In step 1304, the base station determines the power limit constant value of the repeater (

Required for calculation

The value is transmitted to the repeater (see Equation 3 above).

Thereafter, the base station terminates the relay procedure.

The description of the terminal operation according to the fourth embodiment will be omitted since there is no function added to the prior art.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, by performing the cooperative transmission using the maximum ratio transmission in the multi-antenna system, the terminal does not need to know the accurate downlink channel state information (CSI) for decoding. The receiver structure of the terminal is simplified. In addition, the receiver structure of the terminal is independent of the number of repeaters. That is, the terminal does not need to know how many repeaters transmit. In addition, the present invention is superior in BER performance to the conventional SBC MRC method.

Claims (47)

In a relay device performing a maximum ratio transmission in a multi-antenna system cooperatively, A channel estimator receiving a sounding signal or a pilot signal from a terminal and calculating a channel estimation value; A channel gain comparison unit for determining whether to perform cooperative communication with the terminal by comparing the channel estimation value with a channel gain threshold value; In the cooperative communication, reporting the channel estimation value to a base station and calculating a power limit constant value for maximum ratio transmission; And generating relay data using the power limit constant value and the channel estimation value. The method of claim 1, The relay data is a device characterized in that represented by the following equation (9).

Where

silver

It is a transmission matrix transmitted from the repeater to the terminal,

silver

The power limit constant value of the repeater,

Is

Transpose of the channel matrix between the repeater and the multiple antennas of the terminal,

Is a space-time block coded data symbol. The method of claim 1, And a reference data generator for generating pilot data periodically or periodically at the request of the terminal before transmitting the relay data to the terminal. A terminal apparatus for cooperatively performing a maximum ratio transmission in a multi-antenna system, A reference data generator for generating a sounding signal or a pilot signal to be transmitted to the repeaters; A detector for receiving pilot data from repeaters performing cooperative communication with a terminal among the repeaters; A partial channel estimator for calculating partial channel state information using the pilot data; And a demodulator for decoding data using the partial channel state information. The method of claim 4, wherein The partial channel state information is calculated by the following equation (10).

Where

Is a partial channel state information value, and

Is the number of modulated data symbols, and

Is a matrix trace operation on the receiving matrix,

Is defined pilot data. The method of claim 4, wherein And the data decoding is represented by Equation 11 below.

Where

Is a detected and decoded symbol, and

Is a matrix trace operation on the receiving matrix,

Is a defined data symbol, and

silver

The power limit constant value of the repeater,

silver

Of the terminal at the repeater

Channel estimate with the antenna. remind

Is the number of repeaters performing cooperative communication with the terminal,

Is the number of reception antennas of the terminal,

Is partial channel status information. In the base station to perform the maximum ratio transmission in a multi-antenna system cooperatively, A control unit which receives a channel estimation value between the repeater and multiple antennas of the terminal from repeaters performing cooperative transmission with the terminal, A power limiting unit for calculating a power limit constant value for maximum ratio transmission using the channel estimation values of the repeaters; And an RF processor for transmitting the power limitation constant values to the repeaters, respectively. The method of claim 7, wherein The apparatus further comprises a counter for counting the number of repeaters performing cooperative transmission with the terminal. The method of claim 7, wherein And the power limit constant is calculated by Equation 12 under the condition that the transmission power is constant.

Where

Is

The power limit constant value of the repeater,

silver

Of repeater and terminal

Channel estimation value between receiving antennas, and

Is the total channel estimate of the repeater performing cooperative communication.

It is expressed as In a relay device performing a maximum ratio transmission in a multi-antenna system cooperatively, A channel estimation unit for receiving a sounding signal or a pilot signal from the terminal and calculating a channel estimation value; A channel gain comparison unit for determining whether to perform cooperative communication with the terminal by comparing the channel estimation value with a channel gain threshold value; A power limiting unit for calculating a power limiting constant value for maximum ratio transmission using the channel estimation value in the cooperative communication; And a multiplexer for generating relay data using the power limit constant value and the channel estimation value. The method of claim 10, And the power limit constant is calculated by the following Equation (13) under the condition that the transmission power is constant and the power limit constant value is calculated at each relay station.

Where

Is

The power limit constant value of the repeater,

silver

Of repeater and terminal

Channel estimation value between receiving antennas, and

Is the number of reception antennas of the terminal,

Is

The total channel estimate of the repeater. The method of claim 10, The power limitation constant is a device characterized in that the calculated in the following equation under the condition that the receiving power is constant and calculates the power limit constant value in each repeater.

Where

Is

The power limit constant of the repeater

silver

Of repeater and terminal

The channel estimate between the receiving antennas

Is the number of reception antennas of the terminal and

Is

The total channel estimate of the repeater. The method of claim 10, The power limit constant is a device characterized in that it is calculated by the following equation (15) under the condition that the receiving power is constant and the repeater knows the total number of repeaters performing cooperative transmission.

Where

Is

The power limit constant of the repeater

silver

Of repeater and terminal

The channel estimate between the receiving antennas

Is the number of reception antennas of the terminal and

Is

The total channel estimate of the repeater

Is the total number of repeaters with cooperative communication. The method of claim 10, The relay data is a device characterized in that represented by the following equation (16).

Where

silver

It is a transmission matrix transmitted from the repeater to the terminal,

silver

The power limit constant value of the repeater,

Is

Transpose of the channel matrix between the repeater and the multiple antennas of the terminal,

Is a space-time block coded data symbol. The method of claim 10, And a reference data generator for generating pilot data to be transmitted to the terminal before transmitting the relay data. The method of claim 10, And a control unit for notifying the terminal of performing cooperative communication with the terminal before transmitting the relay data. The method of claim 10, And a control unit for notifying the base station that the cooperative communication with the terminal is performed before calculating the power limit constant value. In a terminal performing a maximum ratio transmission cooperatively in a multi-antenna system, A reference data generator for generating a sounding signal or a pilot signal with the repeaters; A partial channel estimator receiving decoding information necessary for decoding relay data from repeaters performing cooperative communication with a terminal among the repeaters; And a demodulator to decode using the decoding information. The method of claim 18, The decoding information is characterized in that the partial channel state information or information for calculating the total number of repeaters performing cooperative transmission with the terminal. The method of claim 18, The partial channel state information is calculated by the following equation (17).

Where

Is a partial channel state information value, and

Is the number of modulated data symbols, and

Is a matrix trace operation on the receiving matrix,

Is defined pilot data. The method of claim 18, And the data decoding is represented by Equation 18 below.

Where

Is a detected and decoded symbol, and

Is a matrix trace operation on the receiving matrix,

Is a defined data symbol, and

silver

The power limit constant value of the repeater,

silver

Of the terminal at the repeater

Channel estimate with the antenna. remind

Is the number of repeaters performing cooperative communication with the terminal,

Is the number of reception antennas of the terminal,

Is partial channel status information. The method of claim 18, The data decoding is represented by the following equation (19).

Where

Is a detected and decoded symbol, and

Is a matrix trace operation on the receiving matrix,

Is the defined data symbol, and

silver

The power limit constant value of the repeater,

silver

Of the terminal at the repeater

Channel estimate with the antenna. remind

Is the number of repeaters performing cooperative communication with the terminal,

Is the number of reception antennas of the terminal,

Is the total number of repeaters performing cooperative communication with the terminal. The method of claim 18, The data decoding is represented by the following equation (20).

Where

Is a detected and decoded symbol, and

Is a matrix trace operation on the receiving matrix,

Is a defined data symbol, and

silver

The power limit constant value of the repeater,

silver

Of the terminal at the repeater

Channel estimate with the antenna. remind

Is the number of repeaters performing cooperative communication with the terminal,

Is the number of reception antennas of the terminal. A base station apparatus for cooperatively performing maximum ratio transmission in a multi-antenna system, A control unit for receiving information on whether to perform cooperative transmission with the terminal from the repeaters; A counter unit for counting the number of repeaters performing cooperative transmission with the terminal using the information; And an RF processor for transmitting information about the total number of repeaters performing cooperative transmission with the terminal to the terminal. In the relay method for cooperatively performing the maximum ratio transmission in a multi-antenna system, Calculating a channel estimation value by receiving a sounding signal or a pilot signal from the terminal; Determining whether to perform cooperative communication with a terminal by comparing the channel estimation value with a channel gain threshold value; In the cooperative communication, reporting the channel estimation value to a base station and receiving a power limit constant value for maximum ratio transmission; And generating relay data using the power limit constant value and the channel estimation value. The method of claim 25, The relaying data is represented by the following Equation 21.

Where

silver

It is a transmission matrix transmitted from the repeater to the terminal,

silver

The power limit constant value of the repeater,

Is

Transpose of the channel matrix between the repeater and the multiple antennas of the terminal,

Is a space-time block coded data symbol. The method of claim 25, Transmitting pilot data to the terminal periodically or periodically at the request of the terminal before transmitting the relay data to the terminal. In the relay method for cooperatively performing the maximum ratio transmission in a multi-antenna system, Transmitting a sounding signal or a pilot signal to the repeaters; Receiving pilot data from repeaters performing cooperative communication with a terminal among the repeaters; Calculating partial channel state information using the pilot data, respectively; And decoding the data by using the partial channel state information. The method of claim 28, The partial channel state information is calculated by the following Equation 22.

Where

Is a partial channel state information value, and

Is the number of modulated data symbols, and

Is a matrix trace operation on the receiving matrix,

Is defined pilot data. The method of claim 28, The data decoding is represented by the following equation (23).

Where

Is a detected and decoded symbol, and

Is a matrix trace operation on the receiving matrix,

Is a defined data symbol, and

silver

The power limit constant value of the repeater,

silver

Of the terminal at the repeater

Channel estimate with the antenna. remind

Is the number of repeaters performing cooperative communication with the terminal,

Is the number of reception antennas of the terminal,

Is partial channel status information. In the relay method for cooperatively performing the maximum ratio transmission in a multi-antenna system, Receiving a channel estimation value between the repeaters and the multiple antennas of the terminal from the repeaters; Calculating a power limit constant value for maximum ratio transmission using the channel estimation values of the repeaters; Transmitting the power limitation constant values to the repeaters, respectively. The method of claim 31, wherein The power limit constant is characterized by the following equation (24).

Where

Is

The power limit constant value of the repeater,

silver

Of repeater and terminal

Channel estimation value between receiving antennas, and

Is the number of reception antennas of the terminal,

Is

With the total channel estimate of the repeater

It is expressed as In the relay method for cooperatively performing the maximum ratio transmission in a multi-antenna system, Calculating a channel estimation value by receiving a sounding signal or a pilot signal from the terminal; Determining whether to perform cooperative communication with a terminal by comparing the channel estimation value with a channel gain threshold value; Calculating a power limit constant value for maximum ratio transmission using the channel estimation value in the cooperative communication; And generating relay data using the power limit constant value and the channel estimation value. The method of claim 33, The power limit constant is characterized by the following equation (25).

Where

Is

The power limit constant value of the repeater,

silver

Of repeater and terminal

Channel estimation value between receiving antennas, and

Is the number of reception antennas of the terminal,

Is

The total channel estimate of the repeater. The method of claim 33, The power limit constant is characterized by the following equation (26).

Where

Is

The power limit constant of the repeater

silver

Of repeater and terminal

The channel estimate between the receiving antennas

Is the number of reception antennas of the terminal and

Is

The total channel estimate of the repeater. The method of claim 33, The power limit constant is characterized by the following equation (27).

Where

Is

The power limit constant of the repeater

silver

Repeater and terminal

The channel estimate between the receiving antennas

Is the number of reception antennas of the terminal and

Is

The total channel estimate of the repeater

Is the total number of repeaters with cooperative communication. The method of claim 33, The relay data is represented by the following equation (28).

Where

silver

It is a transmission matrix transmitted from the repeater to the terminal,

silver

The power limit constant value of the repeater,

Is

Transpose of the channel matrix between the repeater and the multiple antennas of the terminal,

Is a space-time block coded data symbol. The method of claim 33, Transmitting pilot data to the terminal before transmitting the relay data. The method of claim 33, And informing the terminal of performing cooperative communication with the terminal before transmitting the relay data. The method of claim 33, And informing the base station that the cooperative communication with the terminal is performed before calculating the power limit constant value. In the relay method for cooperatively performing the maximum ratio transmission in a multi-antenna system, Transmitting a sounding signal or a pilot signal to the repeaters; Receiving decoding information necessary for decoding relay data from repeaters performing cooperative communication with a terminal among the repeaters; Decoding using the information. 42. The method of claim 41 wherein The decoding information is characterized in that the partial channel state information or information for calculating the total number of repeaters performing cooperative transmission with the terminal. 42. The method of claim 41 wherein The partial channel state information is calculated by the following Equation 29.

Where

Is a partial channel state information value, and

Is the number of modulated data symbols, and

Is a matrix trace operation on the receiving matrix,

Is defined pilot data. 42. The method of claim 41 wherein The data decoding is represented by Equation 30 below.

Where

Is a detected and decoded symbol, and

Is a matrix trace operation on the receiving matrix,

Is a defined data symbol, and

silver

The power limit constant value of the repeater,

silver

Of the terminal at the repeater

Channel estimate with the antenna. remind

Is the number of repeaters performing cooperative communication with the terminal,

Is the number of reception antennas of the terminal,

Is partial channel status information. 42. The method of claim 41 wherein The data decoding is represented by Equation 31 below.

Where

Is a detected and decoded symbol, and

Is a matrix trace operation on the receiving matrix,

Is the defined data symbol, and

silver

The power limit constant value of the repeater,

silver

Of the terminal at the repeater

Channel estimate with the antenna. remind

Is the number of repeaters performing cooperative communication with the terminal,

Is the number of reception antennas of the terminal,

Is the total number of repeaters performing cooperative communication with the terminal. 42. The method of claim 41 wherein The data decoding is represented by the following Equation 32.

Where

Is a detected and decoded symbol, and

Is a matrix trace operation on the receiving matrix,

Is a defined data symbol, and

silver

The power limit constant value of the repeater,

silver

Of the terminal at the repeater

Channel estimate with the antenna. remind

Is the number of repeaters performing cooperative communication with the terminal,

Is the number of reception antennas of the terminal. In the relay method for cooperatively performing the maximum ratio transmission in a multi-antenna system, Receiving information on whether to perform cooperative transmission with the terminal from the repeaters; A counter for counting the number of repeaters performing cooperative transmission with the terminal using the information; And transmitting information on the total number of repeaters performing cooperative transmission with the terminal to the terminal.

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