WO2010121439A1

WO2010121439A1 - Detecting method, device and system for relay cooperative coding

Info

Publication number: WO2010121439A1
Application number: PCT/CN2009/071465
Authority: WO
Inventors: 战金龙; 李晏; 龚政委; 赵琼
Original assignee: 华为技术有限公司
Priority date: 2009-04-24
Filing date: 2009-04-24
Publication date: 2010-10-28
Also published as: CN102549934A; CN102549934B

Abstract

A detecting method, device and system for relay cooperative coding under un-ideal synchronization are provided. The detecting method includes: using at least two receiver antennas to jointly receive a space-time or space-frequency code signal sent by a distributed relay station (11); jointly detecting the signal which is jointly received and obtaining the space-time or space-frequency code signal transmitted by a distributed relay station (12).

Description

Detection method, device and system for relay cooperative coding

Technical field

The present invention relates to the field of communications technologies, and in particular, to a method, device and system for detecting a relay cooperative coding. Background technique

Multi-input multi-output (MIMO) technology can multiply channel capacity without increasing system bandwidth. Relay technology can effectively improve the throughput and hotspots of cell edge users. And coverage of blind spots. The MIMO Relaying technology that combines the two has recently been widely used in the field of wired and wireless communication.

Space time coding is a key technology in MIMO Relaying. Different from traditional space-time coding, distributed space-time coding is where multiple transmit antennas are located at different relay stations, whereas traditional space-time coding is where multiple transmit antennas are located at the same transmitting station. Different relay stations have different distances to the destination, and the propagation environment is different. Therefore, the delay and path loss of the signals transmitted by the relay stations to the receiving end are different. Non-ideal synchronization may cause Inter-Symbol Interference (ISI). The performance of space-time coding is degraded.

The prior art eliminates intersymbol interference due to non-ideal synchronization by adding a pilot symbol in front of the entire data block to be transmitted, using the known pilot at the receiving end. However, in the process of implementing the present invention, the inventors have found through research that the prior art has the following problems:

Adding a pilot dedicated to eliminating intersymbol interference will increase resource overhead; and performance is very sensitive to the magnitude of the delay and there is an error propagation effect. Summary of the invention

Embodiments of the present invention provide a method, a device, and a system for detecting a coordinated cooperative coding, which can eliminate inter-symbol or inter-carrier interference caused by ideal time synchronization, and improve spectrum utilization of space-time or space-frequency coding.

The method for detecting a relay cooperative coding provided by the embodiment of the present invention includes: adopting at least two connections The receiving antenna jointly receives the space-time or space-frequency encoded signal transmitted by the distributed relay station; jointly detecting the jointly received signal to obtain a space-time or space-frequency encoded signal transmitted by the distributed relay station.

The apparatus for detecting a cooperative cooperative coding provided by the embodiment of the present invention includes: a receiving unit, configured to receive, by using at least two receiving antennas, a space-time or space-frequency coded signal transmitted by a distributed relay station; and a detecting unit, configured to The receiving unit jointly performs the joint detection to obtain a space-time or space-frequency encoded signal transmitted by the distributed relay station.

The detection system of the relay cooperative coding provided by the embodiment of the present invention includes a distributed relay station and a detection device for relay cooperative coding, where the distributed relay station is configured to transmit a space-time or space-frequency coded signal, and the detection is performed by the detection The device jointly receives the space-time or space-frequency coded signal by using at least two receiving antennas, and performs joint detection on the jointly received signals to obtain a space-time or space-frequency coded signal transmitted by the distributed relay station.

According to the above technical solution provided by the embodiment of the present invention, by using at least two receiving antennas to jointly receive a space-time or space-frequency coded signal transmitted by a distributed relay station, and then jointly detecting the jointly received signals, the non-ideal synchronization can be eliminated. Caused by inter-symbol or inter-carrier interference, obtaining a space-time or space-frequency coded signal transmitted by the distributed relay station; performance versus delay or frequency offset compared to prior art techniques of adding pilot symbols before the entire transmitted data block The size is not sensitive, there is no need for pilots specifically used to eliminate inter-symbol or inter-carrier interference, and there is no error propagation effect in pilot-based interference cancellation, which can improve the spectrum utilization of space-time or space-frequency coding. DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described. It is obvious that the drawings in the following description are only some embodiments of the present invention. It will be apparent to those skilled in the art that other drawings may be obtained from these drawings without the inventive labor.

1 is a schematic flowchart of a relay cooperative coding detection method according to an embodiment of the present invention; FIG. 2 is a block diagram of a relay cooperative coding detection system according to an embodiment of the present invention; FIG. 4 is a schematic diagram of inter-carrier interference caused by non-ideal synchronization according to an embodiment of the present invention; FIG. 5 is a schematic structural diagram of a relay cooperative coding detection apparatus according to an embodiment of the present invention. detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Referring to FIG. 1, an embodiment of the present invention provides a method for detecting a relay cooperative coding, including: Step 11: jointly receive a space-time or space-frequency coded signal transmitted by a distributed relay station by using at least two receiving antennas;

Step 12: Perform joint detection on the jointly received signals to obtain a space-time or space-frequency encoded signal transmitted by the distributed relay station.

The method for detecting a relay cooperative coding provided by the embodiment of the present invention can jointly detect a space-time or space-frequency coded signal transmitted by a distributed relay station by using at least two receive antennas, and then perform joint detection on the jointly received signal, thereby eliminating non- The inter-symbol interference or the inter-carrier interference caused by the ideal synchronization obtains the space-time or space-frequency coded signal transmitted by the distributed relay station, and the performance delay is compared with the prior art in which the pilot symbol is added before the entire data block transmitted. Or the frequency offset size is not sensitive, there is no need for pilots specifically used to eliminate inter-symbol or inter-carrier interference, and there is no error propagation effect in pilot-based interference cancellation, which can improve the spectrum utilization of space-time or space-frequency coding.

See Figure 2 for an example of a simple system architecture. The source node (Base Station, BS) transmits signals in the form of broadcast. There are two relay nodes (Relay Station, RS) to receive signals. The number of transmitting antennas on each relay node is 1, and two relay nodes (RSI) , RS2) uses Space-Time Block Coding (STBC) for cooperative transmission, and the number of receiving antennas on the mobile station (MS) of the destination node is 2.

First, the source node BS transmits a signal in the form of a broadcast, and two relay stations RS1, RS2 receive a signal. RS1 and RS2 perform space-time coding on the received data to be forwarded, and the transmitted signal S is divided into pairs. Symbol _{S (} 0 = [ ) 2, 0f. Indicates the first code pair after space-time coding, that is, the first transmission period, where each code pair includes 2 symbols.

The relay station (RS1, RS2) adopts Decode and Forward (DF) mode, and adds enough Cyclic Redundancy Check (CRC) code to the transmitted signal S. Only RS 1 and RS2 are correctly verified. The data is forwarded only afterwards.

Corresponding to the transmitted symbol pair s(0 = [ ) 2,0f, the encoded data pair on RS1 is defined as x( -[ (l, x(2,i) , the encoded data pair on RS2 is y() = [j ) The space-time coding matrix constructed by y(2,i)J, RSI and RS2 is:

That is, the encoded data pair transmitted by RS1 in the constructed space-time coding matrix is x(i)

i).

It should be noted that the space-time coding matrix constructed by RS1 and RS2 is not limited to the matrix form of the formula (1), as long as the product of the conjugate transposed matrix of the constructed space-time coding matrix and the space-time coding matrix is guaranteed. Array, it is ok.

Since RS 1 and RS 2 are different from the destination node MS, the delays of x() and y () arriving at the MS are different. Generally, there is a delay offset τ between the RS1 signal received by the MS and the RS2 signal. Since accurate synchronization is difficult, by adjusting the delay, it is assumed that τ does not exceed one symbol period Τ. As can be seen from Figure 3, non-ideal time synchronization will result in inter-symbol interference ISI.

Referring to Figure 3, without loss of generality, assuming that the MS is synchronized to the RSI, the received signal of the MS can be expressed as:

r(l, = (1, + h ₂ (0)y(l,i) + h ₂ (-i)y(2,i _ 1) + n _rd (l,i) (2a) r(2, i) = h _lX (2, i) + h ₂ (0)j(2,) + /3⁄4 (-l)j(l, ) + n _rd (2,) (2b) h ₂ (0) denotes RS2 The channel response between the MS and the MS is the channel response corresponding to the symbol causing the intersymbol interference. ^ is the additive white Gauss noise (AWGN). The degree of influence is represented by:

τ = 0, β = 0; τ = 0.5 Γ , β = 1 (0 άΒ), /3⁄4 (-1) and / ₂ (0) also need to satisfy l) f + | 3⁄4 (0) "< \h ₂ Substituting equation (1) into equation (2), you can get:

r( = Hs( + I( + n _rd ( (4) where: r() = |r( )

1(0 = [(!, 0 Ι(2,Ϊ)] ^Τ =[h ₂ (-\)s Equation (4) can be further expressed as:

= 11β + η, (ί)

H _ie 2x4 matrix, equation (5) is to solve three unknowns using two equations, respectively))), s(l, il), obviously it is impossible to detect the transmitted symbols from equation (5).

However, at this time, the signal that the MS uses two antennas to jointly receive can be expressed as:

[H ₂ H ₃ ]S + n _rd (

H ₄ S + n _rd ( Where hj _k denotes the channel response between the receiving antenna j and the transmitting antenna k.

The matrix of H _{4 e} 4x4, equation (6) is to solve the above three unknowns using four equations, and it is obvious that the transmitted symbols can be detected therefrom.

One detection method is to use Singular Value Decomposition (SVD) method to perform SVD decomposition on H ₃ , find the zero space of H ₃ , and eliminate the influence of ( -1) and ( 2 , ) to detect The first space-time encoded data pair s() = [s(\, i) s(2, i)J.

One detection method is to use the Zero-Forcing (ZF) algorithm to inverse the matrix of the received signal to the left multiplied channel matrix. The received signal is multiplied by the inverse matrix left of m H ₄ H _4):

Thus, it is possible to detect only ² and 0 using the first two lines of equation (7); s( ) and 2, ) can also be detected using lines ¹ , ² , and ⁴ of equation (7).

Another detection method is to construct a W = H (HH ₄ + ^ ² !)- ¹ matrix using the minimum mean square error (MMSE) algorithm, and multiply the received signal by the conjugate transposed matrix of W":

In this way, it is also possible to detect and 2 using only the first two lines of equation (8); and 2, 4 can be detected using lines 1, 2, and 4 of equation (8).

Another detection method is that it can also use the method of serial interference cancellation, for example, using ZF-SIC and MMSE-SIC methods, detecting one symbol at a time, and then removing the symbol from the received signal. The effect of the next symbol is detected until the last symbol is detected.

Different from space-time coding, space-frequency coding is performed in the airspace and frequency domain, while space-time coding is performed in the airspace and time domain. It can be understood that in Orthogonal Frequency Division Multiplexing (OFDM), when the distributed relay station adopts space frequency coding (Space-Frequency Block Coding, SFBC), because the local oscillator of each relay node is different and the Doppler frequency offset, frequency drift occurs between them, resulting in inter-carrier interference (Inter-Carrier Interference, ICI), which will have a serious impact on OFDM systems.

The system structure shown in Fig. 2 is still taken as an example. The source node base station BS transmits a signal in the form of a broadcast, and two relay nodes receive signals, and the number of transmitting antennas on each relay node is 1, and two relay nodes

(RS1, RS2) cooperative transmission using space-frequency coding, and the number of receiving antennas on the mobile station MS of the destination node is 2.

See Figure 4, Figure 4 is a schematic diagram of inter-carrier interference caused by non-ideal synchronization. Assuming that the two adjacent subcarrier channel frequency offsets Δ/ remain unchanged, similar to the derivation process described above, when the spatial frequency coding matrix transmitted by the distributed relay station is:

— x(l, ) j(l, .)

(9)

- (2,/;) (!, ·), where χ( ) = [ _Χ (1, )

^^ is the space-frequency coded data pair transmitted by the first relay station, y(fi) = [y(l,fi) γ(2, )] ^τ =[ ₈ (2, ) s*(l,fi)] ^T For the space-frequency coded data pair transmitted by the second relay station, sCQ = |5(l, /;) s(2, /;)f is the first space-time coded data pair transmitted by the distributed relay station.

It can be understood that the space frequency coding matrix constructed by RS1 and RS2 is not limited to the matrix form of the formula (9), as long as the product of the conjugate transposed matrix of the constructed space frequency coding matrix and the space frequency coding matrix is guaranteed. Array, it is ok.

The signals jointly received by the two receiving antennas on the subcarriers are:

= [H ₂ H ₃ ]S + n _rd (f _i ) where is the first subcarrier,

( ² , / ; ) ] " is the signal received by the first receiving antenna , r ₂ CQ = |r ₂ (l, /;) Γ (2, .) Γ is the signal received by the second receiving antenna, indicating reception The channel response between the antenna and the transmitting antenna, l <j, k < 2, ( ) is additive white Gaussian noise.

The matrix of H _e4 x4, equation (10) is solved by using four equations to solve the above three unknowns, and it is obvious that the transmitted symbols can be detected therefrom. The method for detecting the jointly received signal and detecting the space-frequency coded signal transmitted by the cloth relay station includes:

Performing singular value decomposition on the Η ₃ , finding the zero space of Η ₃ , eliminating the effects of ( ), and ( ² , ), detecting the first space-frequency encoded data pair sCQ = |5(l, ) 5(2, . )Γ; or,

Multiplying the received signal by the inverse matrix m H _{4 of} the 11 ₄ , using a zero-forcing algorithm, detects the first space-frequency encoded data pair _s (y;) = [ i, ) 5 (2, . )f; or,

structure:! ! ^! ^! ^ + ² ^ ¹ , using the least mean square error algorithm, multiplying the received signal by the conjugate transposed matrix \\^ of the W, and detecting the first space-frequency encoded data pair s( .) = |5(l , .) 5(2, .)f; or,

Using the serial interference cancellation algorithm, one symbol is detected each time, and then the effect of the symbol is removed from the received signal, and the next symbol is detected until the last symbol is detected.

The above is the simplest system structure (2 relay nodes, transmitting antennas on each relay node) The number of the receiving antennas on the destination node is 2), and the method for detecting the coordinated cooperative space-time or space-frequency coding provided by the embodiment of the present invention is described. The two receiving antennas are used to jointly receive the distributed relay station. The space-time or space-frequency coded signal is then jointly detected by the jointly received signal, which can eliminate inter-symbol interference or inter-carrier interference caused by non-ideal synchronization, and obtain the space-time or space-frequency coded signal transmitted by the distributed relay station. Compared with the prior art in which pilot symbols are added before the entire data block transmitted, performance is not sensitive to delay or frequency offset, and pilots dedicated to eliminating inter-symbol or inter-carrier interference are not required, and no pilot-based is used. The error propagation effect in interference cancellation can improve the spectrum utilization of space-time or space-frequency coding.

There are two points to be explained. First, when a distributed relay node uses two relay stations to cooperatively forward space-time or space-frequency encoded data packets, the receiving end only needs to use two receiving antennas for joint reception, thereby eliminating non-ideal synchronization. The inter-symbol interference or inter-carrier interference caused by the following, if the receiving end uses more receiving antennas for joint reception, the redundant antenna can be used to obtain the diversity gain and improve the performance of space-time or space-frequency coding.

Second, the present invention is not limited to the cooperative coding case where the relay node is two, and is applicable to more than two distributed relay nodes. In this case, the receiving end needs to increase the number of receiving antennas accordingly to eliminate the non- More intersymbol interference or inter-carrier interference caused by ideal time synchronization. The method may be that the distributed relay stations are assembled, a simple space-time or space-frequency coding matrix is constructed, and the space-time or space-frequency coded signals after the combination are transmitted to reduce the number of interference symbols or interference carriers. .

Referring to FIG. 5, on the basis of the foregoing method embodiments, an embodiment of the present invention provides a detection apparatus for a relay cooperative coding, including:

The receiving unit 51 is configured to jointly receive the space-time or space-frequency encoded signal transmitted by the distributed relay station by using at least two receiving antennas;

The detecting unit 52 is configured to perform joint detection on the signals jointly received by the receiving unit, to obtain a space-time or space-frequency encoded signal transmitted by the distributed relay station.

When the space-time coding matrix transmitted by the distributed relay station is as shown in the formula (1), the signal that the receiving unit 41 jointly receives by using any two receiving antennas is as shown in the formula (6). When the space-frequency coding matrix transmitted by the distributed relay station is as shown in the formula (9), the signal that the receiving unit 41 jointly receives by using any two receiving antennas is as shown in the formula (10).

At this time, the detecting unit 52 can detect by using any of the following modules:

The singular value detection module 521 is configured to perform singular value decomposition on the 11 ₃ to find the zero space of H _{3 ;} the zero-forcing detection module 522 is configured to multiply the received signal by the inverse matrix of the 11 ₄ Ά _Α );

The minimum mean square error detecting module 523 is configured to construct \¥ = 1^(1^11 ₄ + 0 ₀ ² 1) ^-1 , and multiply the received signal by the conjugate transposed matrix W ^{ff of the} W;

The serial interference cancellation detection module 524 is used for checking one by one.

The embodiment of the present invention further provides a detection system for relay cooperative coding, which includes a distributed relay station and the above-mentioned detection apparatus for relay cooperative coding, wherein the distributed relay station is configured to transmit a space-time or space-frequency coded signal, The detecting device uses the at least two receiving antennas for joint reception, and performs joint detection on the jointly received signals to obtain a space-time or space-frequency encoded signal transmitted by the distributed relay station.

As shown in Fig. 3, a simple system includes two relay nodes, the number of transmitting antennas on each relay node is one, and the number of receiving antennas on the detecting device is two. For more details, refer to the foregoing method and device embodiments, and details are not described herein again.

The technical solution provided by the present invention uses at least two receiving antennas to jointly receive signals transmitted by the distributed relay station; detecting the jointly received signals, detecting signals transmitted by the distributed relay station, and performance is not for delay or frequency offset Sensitive, there is no error propagation effect in pilot-based interference cancellation, no pilots dedicated to eliminating intersymbol interference, and can be applied to inter-carrier interference in space-frequency coding of Orthogonal Frequency Division Multiplexing (OFDM) systems. The elimination, the receiving end performs space/space frequency joint processing on the received signal, thereby detecting the transmitted signal under non-ideal synchronization, thereby improving spectrum utilization.

A person skilled in the art will also appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. The interchangeability of hardware and software is clearly illustrated, and the components and steps of the examples have been generally described in terms of functions in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods to implement the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

The steps of a method or algorithm described in connection with the embodiments disclosed herein can be implemented in hardware, a software module executed by a processor, or a combination of both. Software modules can be placed in random access memory

(RAM), memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

Claim

A method for detecting a relay cooperative coding, comprising:

The space-time or space-frequency coded signals transmitted by the distributed relay station are jointly detected by the at least two receiving antennas to jointly detect the signals received by the distributed relay station, and the space-time or power-frequency coded signals transmitted by the distributed relay station are obtained.

The detection method according to claim 1, wherein the conjugate transposed matrix of the matrix formed by the space-time or space-frequency encoded signal transmitted by the distributed relay station and the space-time or space-frequency encoded signal form a matrix The product of the unit is a unit array.

3. The method according to claim 2, wherein the distributed relay station uses a space-time coded signal transmitted by two relay stations to form a matrix:

Where x(i) = [x(l,i) x(2,i)] ^T =[s(l,i) _s*(2,i)] ^T is the space-time encoded data transmitted by the first relay station Yes, y(i) = [y(U) y(2,i)] ^T =[s(2,i) 3*(1 ] is the space-time encoded data pair transmitted by the second relay station, _S (0 = [ U) 2, 0f is the ζ·····················

The signals received jointly by any two receiving antennas are:

[H ₂ H ₃ ]S + n _rd (

H ₄ S + n _rd ( Where _r ;(2,i)] ^T is the signal received by the first receiving antenna, r ₂ ( = [r ₂ (l,

The signals received by the two receiving antennas represent the channel response between the receiving antenna and the transmitting antenna, l <j, k < 2, ^ (0 is additive white Gaussian noise.

The detection method according to claim 2, wherein the matrix formed by the space-frequency coded signals transmitted by the distributed relay station is:

- (2,/;) (!, .) where /;· is the first subcarrier, x(fi) = [ _X (l,fi) x(2,f _i )] ^T =[s(l,f _i ) -8*(2, )] is the space-frequency coded data pair transmitted by the first relay station, y(fi) = [y(l,fi) γ(2,ΐ^ = (2,^) ^(^ ^ for the space-frequency coded data pair transmitted by the second relay station, sCQ = [ 1, /;) 2, /;) f is the first space-frequency coded data pair transmitted by the distributed relay station;

The signal received jointly by any two receiving antennas is: h; ₂ (f _i _ ₁ )s*(2,f _i )

+ + n _rf (f ₁ )

Κ( Κ( K(^) o s(l,f;)

h (f) -h^f o h^f^) s(2,f;)

s*(2,f;)

H ₃

H ₄

= [H ₂ H ₃ ]S + n _rd (f ₁ ) where r ;)^;^,^ _{r (2} ,/;.)f is the signal received by the first receiving antenna, r ₂ ( )-h )

For the signal received by the second receiving antenna, hj _k represents the channel response between the receiving antenna and the transmitting antenna, \ j, k 2, " _rd (/;) is additive white Gaussian noise.

The method according to claim 3 or 4, wherein the performing joint detection on the jointly received signals comprises: Singular value decomposition algorithm, the singular value decomposition H _3, ₃ to find the null space of H; or zero forcing algorithm, the received signal is multiplied by the left inverse matrix of m 11 ₄ H ₄₎ Or, using the least mean square error algorithm, construct

Multiplying the received signal by the conjugate transposed matrix W ^{ff of the} W; or

The serial interference cancellation algorithm is used to detect the symbols one by one.

6. A detection device for relay cooperative coding, comprising:

a receiving unit, configured to jointly receive a space-time or space-frequency coded signal transmitted by the distributed relay station by using at least two receiving antennas;

And a detecting unit, configured to perform joint detection on the signals jointly received by the receiving unit, to obtain a space-time or space-frequency encoded signal transmitted by the distributed relay station.

7. The detecting device according to claim 6, wherein when the distributed relay station is adopted

s(2,i) The matrix of the space-time coded signals transmitted by the two relay stations is:

Time,

Where x(i) = [x(l,i) x(2,i)] ^T =[s(l,i) -s*(2,i)] ^T is the space-time coding transmitted by the first relay station Data pair, y(i) = [y(l,i) y(2,i)] ^T =[s(2,i) s*(l,i)] ^T is the space-time coding transmitted by the second relay station Data pair, _s (o = [ U) 2, 0f is the second space-time coded data pair transmitted by the distributed relay station;

The receiving unit uses any two receiving antennas to jointly receive signals:

= [H ₂ H ₃ ]S + n _rd (

= H ₄ S + n _rd (

Where _r ;{2,i) is the signal received by the first receiving antenna, r ₂ ( = [r ₂ (l,

The signals received by the two receiving antennas represent the channel response between the receiving antenna and the transmitting antenna, l <j, k < 2, which is additive white Gaussian noise.

8. The detecting apparatus according to claim 6, wherein when the distributed relay station uses the space-frequency coded signals transmitted by the two relay stations, the matrix is:

x( fy(2,f _i ) - (2, ) (1, ) where _χ ( ) = [ _χ (1, ) x(2,f _i )] ^T =[s(l,f _i ) -8 *(2, ) is the space-frequency coded data pair transmitted by the first relay station, y(fi) = [y(l,fi) γ(2,ΐ^ =[ (2,^) ^^ is the second relay station The transmitted space-frequency coded data pair, s(0 = [ ) 2, 0f is the first space-time coded data pair transmitted by the distributed relay station; the receiving unit uses any two receive antennas to jointly receive the signal:

= [H ₂ H ₃ ]S + n _rd (f _i ) where /; is the first subcarrier,

) (2, /;·)]" is the signal received by the first receiving antenna, r ₂ CQ = |r ₂ (l, /;) ^(2, /,) is the signal received by the second receiving antenna, Indicates the channel response between the receiving antenna and the transmitting antenna. l <j,k <2, ^ ( ) is additive white Gaussian noise.

9. The detecting device according to claim 7 or 8, wherein the detecting unit comprises any one of the following modules:

a singular value detection module, configured to perform singular value decomposition on the H ₃ to find a zero space of H _{3 ;} a zero-forcing detection module, configured to multiply the received signal by the inverse matrix of the H ₄ (H) ₄ ); Minimum mean square error detection module, used to construct:! ! ^! ^! ^ + ² ^ ¹ , multiplying the received signal by the conjugate transposed matrix of the W \\^;

The serial interference cancellation detection module is used for checking one by one.

A detection system for relay cooperative space-time coding, comprising: a distributed relay station and the detection device according to any one of claims 6 to 9, wherein the distributed relay station is configured to transmit a space time Or the space-frequency coded signal is jointly received by the detecting device by using at least two receiving antennas, and the jointly received signals are jointly detected to obtain a space-time or space-frequency coded signal transmitted by the distributed relay station.