CN101944942A - Low-complexity adaptive transmission multi-antenna transmission method and system - Google Patents

Abstract

The invention discloses the multi-antenna transmission methods and system of a kind of transmission of low-complicacy self-adaptive, this method comprises: according to the channel information and formula of acquisition:

Equivalent channel construction is carried out,And Signal to Interference plus Noise Ratio after single stream detects is calculated by equivalent channel matrix,MCS is selected according to throughput-maximized principle,Transmitting terminal is encoded and is modulated to transmission symbol according to the MCS of selection,And it is carried out symbol after space time processing using determining coding form never with being sent on physical antenna; Receiving end receives the symbol that the transmitting terminal is sent,The equivalent channel matrix of symbol experience is constructed by equivalent channel matrix constructive formula by actual channel estimation,And then MMSE linearity test is carried out using equivalent channel matrix; It finally completes by the symbol after detecting to the processing to bit information estimation is sent. The present invention detects optimum code using MMSE, and SCE Single Channel Encoder transmission can be used, and computation complexity when multiaerial system carries out Adaptive Transmission is effectively reduced.

Description

A kind of multi-antenna transmission method and system of low-complicacy self-adaptive transmission

Technical field

The present invention relates to the mobile communication technology field, specifically, is a kind of multi-antenna transmission method and system that detects the Adaptive Transmission of optimum code based on least mean-square error (MMSE).

Background technology

Multiple-input and multiple-output (Multiple Input Multiple Output, MIMO) technology is considered to one of important breakthrough of modern communication technology, by at many antennas of transmitting terminal and receiving terminal equipment, utilizing between each antenna independently, communication environments comes expanding system capacity and/or elevator system reliability.The MIMO technology mainly contains two branches at present, one class is transmitted the data flow of carrying different information based on the thought of data multiplex on the many antennas, and receiver is distinguished each aerial information by certain treatment technology, thereby the elevator system overall transmission rate, the throughput of increase multiaerial system; Another kind of thought based on diversity is made a start and is launched from many antennas behind the encoding operation when data are flow to line space and since on each antenna data to be in the probability of deep fade simultaneously very little, thereby guaranteed the accurate reception of information flow.As the typical case of first branch representative, structure and corresponding algorithm for reconstructing when people such as Poschini have at first proposed to can be applicable to mimo channel a kind of empty.The transmission means of this spatial reuse is called BLAST (Bell Labs Layered Space-Time), and the basic structure of general space multiplexing system is seen Fig. 1.

BLAST coding comprises two kinds of encoding scheme: V-BLAST and H-BLAST, the letter representation of front the different direction that on the room and time dimension, presents of processing to received signal.If the signal of sending from the individual parallel channel encoder of m (legend is established m=4) as shown in Figure 2, wherein c _IjExpression moment i+1 (the expression bit transfer moment, is-not symbol transmission time) is from the bit of encoder j transmission.

The V-BLAST encoder receives the output symbol from the parallel channel encoder, carries out space encoding by vertical direction, and its principle as shown in Figure 3.As can be seen from Figure 3, same encoder produces bit experience different antennae and sends, and the encoder number might not require to equate with antenna number.

The H-BLAST encoder receives the output symbol from the parallel channel encoder, carry out space encoding by horizontal direction, be that code element behind each channel encoder coding directly send corresponding antenna (channel encoder and antenna are one to one) to send, its principle as shown in Figure 4.

Compare two kinds of multiplexing transmission schemes, the V-BLAST mode can experience independently Channel Transmission because of check bit and the systematic bits that it has the identical systems bit information, so can obtain certain diversity gain.

In closed-loop system, when knowing the channel quality information of feedback when making a start, can select suitable modulation coding mode with control transmission speed, thereby obtain system's maximum throughput, be that the Adaptive Modulation and Coding mode is selected (Adaptive Modulation Coding, AMC), so receiving terminal (Modulation and Coding Scheme, MCS) sequence number feeds back to transmitting terminal with the modulation coding mode selected.The closed-loop system of multiplexing transmission adopts wire rate control every day (the Per Antenna Rating Control based on H-BLAST at present, PARC) transmission can easily not carried out the AMC operation based on the multiplexing transmission of V-BLAST because can not conveniently obtaining Signal to Interference plus Noise Ratio after the unified detection.

Application number is 200810041892.4, name is called the Chinese patent application of " method and apparatus that is used for adaptive coding and modulating ", a kind of method and apparatus of using space-time/frequency block code in the adaptive coding and modulating scheme is provided, it arrives spatial domain and frequency domain to data map by space-time/frequency block code, be only required in that frequency direction needs the even number subcarrier and unrestricted to time orientation, this invention uses a cover AMC mode to support single current and stream transmission, simplify the realization cost and the complexity of software and hardware, reduced the buffer memory demand and the decoding delay of system.But its speed that is primarily aimed at space-time/frequency block code is 1 diversity transmission system, and is also inapplicable to the multiplex system of high rate data transmission.

Application number is 200510041805.1, name is called in the Chinese patent application of " a kind of method that obtains the full diversity gain based on the diagonal angle layered space-time architecture ", a kind of method that obtains the full diversity gain based on the diagonal angle layered space-time architecture is provided, its basic matrix at random that at first adopts one group of optimum during to vertical layered space in (V-BLAST) structure the transmission grouping in each symbol period carry out modulation on the space, again the signal in the spatial domain is sent along diagonal in time domain subsequently.The form that sends can obtain the full diversity gain in (V-BLAST) structure availability of frequency spectrum when not losing vertical layered space, realize the dual optimization on the availability of frequency spectrum and the performance, thereby can when not reducing the V-BLAST structure availability of frequency spectrum, obtain the full diversity gain, improve the transmission performance of system.This structure can adopt continuous ZF and cancellation algorithms to detect in addition, makes its receiver have lower implementation complexity.

Application number is 200480044343.2, name is called in the Chinese patent application of " link-adaptation system in the multi-input multi-output orthogonal frequency division multiplexing system with and method ", link-adaptation system in a kind of MIMO-OFDM system is provided, in this system, the V-BLAST processing unit is handled, and this V-BLAST is treated to the processing that accordingly received signal is separated into data flow with a plurality of antennas of dispensing device.The Vector Message output unit will be handled the feedback vector information that obtains by V-BLAST and send to dispensing device.The adaptive bit allocation units to each subcarrier by different antenna transmission, are controlled the bit number that is distributed based on feedback vector information adaptively.The adaptive power allocation units distribute power based on feedback vector information to each antenna self-adaptive ground.But this technology is adaptive distribution power, can not obviously improve the system throughput performance.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of multi-antenna transmission method and system of low-complicacy self-adaptive transmission, this method detects optimum code based on least mean-square error (MMSE), can reach MMSE linearity test optimal performance, based on the transmission plan of this coding for the detection of each transmission symbol after Signal to Interference plus Noise Ratio identical, promptly can use the SCE Single Channel Encoder transmission, system can obtain obvious diversity gain when system adopts the chnnel coding of low code check, and the present invention can carry out the Adaptive Modulation and Coding mode of single bit stream and select, and obviously reduces system's computational complexity.

In order to solve the problems of the technologies described above, technical scheme of the present invention is achieved in that

A kind of multi-antenna transmission method of low-complicacy self-adaptive transmission, this method detects optimum code based on MMSE, comprising:

Obtain channel information, according to described channel information, according to formula:

The structure equivalent channel matrix, and calculate single current by equivalent channel matrix and detect the back Signal to Interference plus Noise Ratio, select modulation coding mode MCS according to throughput-maximized principle, according to the MCS that selects transmission symbol is encoded and modulates by transmitting terminal, and after handling when utilizing the coding form of determining to carry out sky with symbol never with sending on the physics antenna;

Receiving terminal receives the symbol that described transmitting terminal sends, according to formula:

Estimate to construct the equivalent channel matrix of symbol experience by actual channel, and then utilize equivalent channel matrix to carry out the MMSE linearity test; Finish at last by the symbol after detecting to the processing that the transmission bit information is estimated;

Wherein: H _EqDimension is (N _r* N _t) * K, N _tBe transmitting antenna radical, N _rBe the reception antenna radical, and N _r〉=N _t, K is the number of complex symbol. Expression N _t* N _tUnit matrix,

Represent straight product, H is N _r* N _tDimension channel fading matrix, A are the diffusion matrix of N * N dimension, N=N _t, vec (A) represents the matrix A vector quantization, order

Then

Further, the described channel information that obtains, the structure equivalent channel matrix, and calculate single current by equivalent channel matrix and detect the back Signal to Interference plus Noise Ratio, select the step of modulation coding mode MCS to finish according to throughput-maximized principle by transmitting terminal or receiving terminal.

Further, in tdd systems, the mode that described transmitting terminal obtains channel information is: extract described channel information and calculate equivalent channels information from the ascending channel detecting result by channel reciprocity.

Further, in frequency division duplex system, the mode that described transmitting terminal obtains MCS is: obtain channel and select MCS by the channel information that obtains the receiving terminal feedback, perhaps select behind the MCS result to be fed back to transmitting terminal at receiving terminal.

Further, described MMSE detects the optimum code code word and represents by the form of linear diffuse code, promptly

And the diffusion matrix of coding is met the following conditions:

$A_i{A}_i^H=\frac{N}{K}{I}_N,$ And

$\mathrm{Trace}\left(A_i^H{A}_j\right)=0,$ $\∀i\≠j$

Wherein, [] ^HConjugate transpose is got in expression, and matrix trace is asked in Trace () expression.

The invention also discloses a kind of multi-aerial transmission system of low-complicacy self-adaptive transmission, this system detects optimum code based on MMSE, comprises transmitting terminal and receiving terminal, and the transmitting terminal of the described MCS of having selection function comprises:

The channel extraction module is used to obtain channel information;

The Adaptive Modulation and Coding module is used to receive the channel information that described channel extraction module obtains, and carries out the equivalent channel structure, and calculates single current and detect the back Signal to Interference plus Noise Ratio, selects modulation coding mode MCS by throughput-maximized principle;

Channel coding module, the code rate information that is used for determining according to described Adaptive Modulation and Coding module is encoded to the transmission data bit;

Modulation module is used for the bit information behind the coding is modulated;

The Space Time Coding module is handled when the transmission symbol after being used to utilize definite coding form to modulation carries out sky;

Sending module, the symbol after handling when being used for sky is never with sending on the physics antenna;

Described receiving terminal comprises:

The equivalent channel constructing module is used for according to formula

Estimate to construct the equivalent channel matrix of symbol experience by actual channel;

Detection module is used to utilize described equivalent channel matrix to carry out the MMSE linearity test;

Demodulation module is used to finish by the symbol after detecting to the processing that the transmission bit information is estimated;

Wherein: H _EqDimension is (N _r* N) * and K, N _tBe transmitting antenna radical, N _rBe the reception antenna radical, and N _r〉=N _t, K is the number of complex symbol.

Expression N _t* N _tUnit matrix,

Represent straight product, H is N _r* N _tDimension channel fading matrix, A are the diffusion matrix of N * N dimension, and vec (A) represents the matrix A vector quantization, order

Then

Further, in frequency division duplex system, described receiving terminal also comprises:

The channel feedback module is used for the channel information that the receiving terminal channel estimating obtains is later on sent to transmitting terminal by closed-loop feedback manner;

The channel extraction module of described transmitting terminal is determined described channel information by the channel information that obtains the receiving terminal feedback.

Further, in tdd systems, described transmitting terminal extracts described channel information by channel reciprocity from the ascending channel detecting result.

Further, described MMSE detects the optimum code code word and represents by the form of linear diffuse code, promptly And the diffusion matrix of coding is met the following conditions:

$A_i{A}_i^H=\frac{N}{K}{I}_N,$ And

$\mathrm{Trace}\left(A_i^H{A}_j\right)=0,$ $\∀i\≠j$

Wherein, [] ^HConjugate transpose is got in expression, and it is the number of complex symbol that matrix trace, K are asked in Trace () expression.

The present invention also provides the multi-aerial transmission system of another kind of low-complicacy self-adaptive transmission, and this system detects optimum code based on MMSE, comprises transmitting terminal and receiving terminal, and the receiving terminal of the described MCS of having selection function comprises:

The channel extraction module is used to obtain channel information;

The equivalent channel constructing module is used for according to formula

Estimate to construct the equivalent channel matrix of symbol experience by actual channel;

The Adaptive Modulation and Coding module is used for calculating single current according to equivalent channel and detects the back Signal to Interference plus Noise Ratio, selects modulation coding mode MCS by throughput-maximized principle;

The MCS feedback module is used for the MCS that the Adaptive Modulation and Coding module is selected is fed back to described transmitting terminal;

Detection module is used to utilize described equivalent channel matrix to carry out the MMSE linearity test;

Demodulation module is used to finish by the symbol after detecting to the processing that the transmission bit information is estimated;

Described transmitting terminal comprises:

Channel coding module is used for according to the code rate information of described MCS feedback module feedback the transmission data bit being encoded;

Modulation module is used for the bit information behind the coding is modulated;

The Space Time Coding module is handled when the transmission symbol after being used to utilize definite coding form to modulation carries out sky;

Sending module, the symbol after handling when being used for sky is never with sending on the physics antenna;

Wherein: H _EqDimension is (N _r* N _t) * K, N _tBe transmitting antenna radical, N _rBe the reception antenna radical, and N _r〉=N _t, K is the number of complex symbol.

Expression N _t* N _tUnit matrix,

Represent straight product, H is N _r* N _tDimension channel fading matrix, A are the diffusion matrix of N * N dimension, N=N _t, vec (A) represents the matrix A vector quantization, order Then

Multi-antenna transmission method and system based on the low-complicacy self-adaptive transmission of the present invention detects the multi-antenna transmission method and the system of optimum code based on MMSE, use MMSE to detect optimum code, promptly this is encoded to the coded system that can reach the performance of BER optimum under the MMSE linearity test condition, and this coded system makes that Signal to Interference plus Noise Ratio is identical after every symbol detection, can use the SCE Single Channel Encoder transmission, system can obtain obvious diversity gain when system adopts the chnnel coding of low code check, thereby obtain a kind of single current Adaptive Modulation and Coding processing scheme, the computation complexity when effectively reduction system carries out Adaptive Transmission.

Description of drawings

Fig. 1 is the basic structure schematic diagram of general BLAST system;

Fig. 2 is a schematic diagram of sending signal from m parallel channel encoder;

Fig. 3 is V-BLAST coding principle figure;

Fig. 4 is H-BLAST coding principle figure;

Fig. 5 is of the present invention based on the multi-antenna transmission method of low-complicacy self-adaptive transmission and the overall transfer block diagram of system;

Fig. 6 be of the present invention based in the multi-aerial transmission system of low-complicacy self-adaptive transmission as the base station model schematic diagram of transmitting terminal;

Fig. 7 be of the present invention based in the multi-aerial transmission system of low-complicacy self-adaptive transmission as the user terminal model schematic diagram of receiving system.

Embodiment

The invention will be further described below in conjunction with the drawings and specific embodiments, can be implemented so that those skilled in the art can better understand the present invention also, but illustrated embodiment is not as a limitation of the invention.

The present invention uses MMSE to detect optimum code, makes that Signal to Interference plus Noise Ratio (SINR) is identical after every symbol detection, thereby obtains a kind of single current Adaptive Modulation and Coding processing scheme, the computation complexity when effectively reduction system carries out Adaptive Transmission.Below technical scheme of the present invention is described in detail.

Channel coding schemes of the present invention is as follows:

Make single link that N is arranged _tThe root transmitting antenna, N _rRoot reception antenna, and N _r〉=N _t, then system model is:

Y＝HX+W (1)

Wherein, the linear Space-Time Block Coding X that contains K complex symbol is for x ₁..., x _KN for element _t* N dimension Space-Time Block Coding matrix; H is N _r* N _tDimension channel fading matrix, its element h _Ij(1≤i≤N _r, 1≤j≤N _t) Rayleigh distributed; Y is N _r* N ties up received signal; W is σ for obeying average power _nAdditive white Gaussian noise.

Consider the square formation coding, i.e. N=N _t, utilizing the linear diffuse coding processing method of plural form, linear Space-Time Block Coding X can be expressed as

Wherein, A _iBe the diffusion matrix of N * N dimension, then formula (1) can be rewritten into the following equivalent form of value:

$\tilde{y}=H_{\mathrm{eq}}\tilde{x}+\tilde{n}---\left(2\right)$

Wherein,

[] ^TTransposition is got in expression,

Be the noise matrix vector quantization, and in the formula:

$H_{\mathrm{eq}}=(I_{N_t}\⊗H)\×[\mathrm{vec}\left(A_1\right),...,\mathrm{vec}\left(A_K\right)]---\left(3\right)$

Wherein,

Represent straight product, promptly Kronecker is long-pending, Expression N _t* N _tUnit matrix, H _EqDimension is (N _r* N) * and K, vec (A) represents the matrix A vector quantization, order

Use linear MMSE detection algorithm, order

Then the signal estimated value is:

$\hat{x}=G\tilde{y}---\left(4\right)$

Signal to Interference plus Noise Ratio can be represented with following formula after the detection of distinct symbols transmission:

${\mathrm{SINR}}_i=\frac{{\left|g_i{h}_i\right|}^2}{\underset{j=1,j\≠i}{\overset{K}{\mathrm{\Σ}}}{\left|g_i{h}_j\right|}^2+{\mathrm{\σ}}_n^2{\left|\right|g_i\left|\right|}^2}---\left(5\right)$

G in the formula _iThe i of expression G is capable, h _jExpression H _EqJ row, in a code period, i=1 ..., K.

When the coding diffusion matrix satisfies condition (6-a) and (6-b) time, this Space Time Coding is the (reference: J.Liu of error performance optimum under the MMSE linearity test, J.-K.Zhang, and K.M.Wong, " On the design of minimum BER linear space-time block codes for MIMO systems equipped with MMSE receivers ", IEEE Trans.Signal Processing, vol.54, No.8, PP.3147-3158, Aug.2006.), promptly " MMSE optimum code ".

$A_i{A}_i^H=\frac{N}{K}{I}_N---(6-a)$

$\mathrm{Trace}\left(A_i^H{A}_j\right)=0,$ $\∀i\≠j---(6-b)$

Order

Then in the formula [] ^HConjugate transpose is got in expression, and Trace () then represents to ask matrix trace.Following formula (6-b) can be equivalent to

Theorem: satisfy condition (6-a) and prerequisite (6-b) under, it is identical that the MMSE of each symbol detects back SINR.

Below above-mentioned theorem is proved:

The first step: under the MMSE testing conditions, formula (5) can be converted into by each stream mean square error (MSE for detecting back SINR calculating _i) express:

${\mathrm{SINR}}_i=\frac{1}{{\mathrm{MSE}}_i}-1=\frac{1}{{\mathrm{\σ}}_n^2{\left[{({\mathrm{\σ}}_n^2{I}_K+{H_{\mathrm{eq}}}^H{H}_{\mathrm{eq}})}^{-1}\right]}_{i,i}}-1---\left(7\right)$

If work as i=1 ..., during K, formula (7) is all equal, i.e. matrix M ₁ ^-1Diagonal entry all identical, define by matrix inversion

Wherein, M ^*For the adjoint matrix of M, because of M ₁ ^-1Diagonal entry is identical, then The algebraic complement diagonal entry identical, M just ₂=H _Eq ^HH _EqThe algebraic complement diagonal entry identical, promptly be equivalent to M ₂ ^-1=(H _Eq ^HH _Eq) ^-1Diagonal entry identical.

Second step: because

Again

Then

So former theorem proof is equivalent to the proof formula

Diagonal entry is identical.

The 3rd step: order

Wherein m and a are column vector, then

Its diagonal entry is made as m ₁, m ₂...,

Formula (8) decomposed and through deriving:

$m_l=(a_l\left(1\right)a_l^{*}\left(1\right)+a_l(N_t+1)a_l^{*}(N_t+1)+...a_l({N_t}^2-N_t+1)a_l^{*}({N_t}^2-N_t+1))m_1---\left(1\right)$

$+(a_l\left(1\right)a_l^{*}\left(2\right)+a_l(N_t+1)a_l^{*}(N_t+2)+...a_l({N_t}^2-N_t+1)a_l^{*}({N_t}^2-N_t+2))m_1---\left(2\right)$

$+...+(a_l\left(N_t\right)a_l^{*}\left(N_t\right)+a_l\left(2N_t\right)a_l^{*}\left(2N_t\right)+...a_l\left({N_t}^2\right)a_l^{*}\left({N_t}^2\right))m_{N_t}\left(N_t\right)$

Wherein, l=1 ..., N _t

Get by condition (6-a),

$\left\{\begin{array}{c}{a}_l\left(i\right)a_l^{*}\left(i\right)+a_l(N_t+i)a_l^{*}(N_t+i)+...a_l({N_t}^2-N_t+i)a_l^{*}({N_t}^2-N_t+i)=1\\ a_l\left(i\right)a_l^{*}\left(j\right)+a_l(N_t+i)a_l^{*}(N_t+j)+...a_l({N_t}^2-N_t+i)a_l^{*}({N_t}^2-N_t+j)=0\end{array}\right.,i\≠j$

Then $m_1=m_2=...=m_{N_t}.$

So far, provable formula

Diagonal entry is identical, and promptly proof can obtain the theorem conclusion: satisfy condition (6-a) and prerequisite (6-b) under, the MMSE of each symbol detects that afterwards SINR is identical.

Known coded diffusion matrix constraints is verified in the complete orthogonal basis based on Clifford algebraically, obtains conclusion: the complete orthogonal basis of Clifford satisfies constraints (6-a) and (6-b) just.Below provide complete orthogonal basis acquisition methods, and provide the coded system of different antennae number thus based on Clifford algebraically.

Complete orthogonal basis quantity:

For 2 ^L* 2 ^LComplex matrix, its complete orthogonal basis is 2 ^2L=(2 ^L) ²Individual orthogonal matrix constitutes, and empirical tests all meets the diffusion matrix condition of MMSE optimum code, promptly can obtain the coding structure of multiplex rate transmission.

For different dimensions N * N (N=2 ^L) Clifford orthogonal basis matrix constructive method:

At first define initial matrix:

${\mathrm{\α}}_1=\left[\begin{array}{cc}0& 1\\ -1& 0\end{array}\right],$ ${\mathrm{\α}}_2=\left[\begin{array}{cc}0& j\\ j& 0\end{array}\right]$ With ${\mathrm{\α}}_3=\left[\begin{array}{cc}1& 0\\ 0& -1\end{array}\right]$

Then, the Clifford algebra matrix can be expressed as Cliff _2K-2, its complete representation is a transition matrix:

...

...

The acquisition methods of complete orthogonal basis:

Each orthogonal basis is by Cliff _2LThe basic algebra matrix C of 2L ₁～C _2K-2, unit matrix and their product obtain.

This shows, can push away by any configuration 2 from above-mentioned conclusion ^LThe transmission system of root transmitting antenna can be designed corresponding M MSE optimum code.

Concrete building method is example explanation (other dimensions repeat no more) with two antennas and four antennas, and is specific as follows:

1, two antenna coding forms:

At first, obtain the diffusion matrix that two antennas are encoded, following A based on the Clifford algebra matrix ₁～A ₄

$A_1=\frac{1}{\sqrt{2}}{I}_2=\frac{1}{\sqrt{2}}\left[\begin{array}{cc}1& 0\\ 0& 1\end{array}\right],$ $A_2=\frac{1}{\sqrt{2}}{\mathrm{\α}}_1=\frac{1}{\sqrt{2}}\left[\begin{array}{cc}0& 1\\ -1& 0\end{array}\right],$

$A_3=\frac{1}{\sqrt{2}}{\mathrm{\α}}_2=\frac{1}{\sqrt{2}}\left[\begin{array}{cc}0& j\\ j& 0\end{array}\right],$ $A_4=\frac{1}{\sqrt{2}}{\mathrm{\α}}_1\×{\mathrm{\α}}_2=\frac{1}{\sqrt{2}}\left[\begin{array}{cc}j& 0\\ 0& -j\end{array}\right]$

Wherein,

Guarantee antenna normalization, thereby obtain the coding form of two antennas:

$X_2=\frac{1}{\sqrt{2}}\left[\begin{array}{cc}{x}_1+j{x}_4& x_2+j{x}_3\\ -x_2+j{x}_3& x_1-j{x}_4\end{array}\right]---\left(9\right)$

Getting its equivalent channel form by formula (3) is

$H_{\mathrm{eq}}=\left[\begin{array}{cccc}{h}_{11}& -h_{12}& {\mathrm{jh}}_{12}& {\mathrm{jh}}_{11}\\ h_{21}& -h_{22}& {\mathrm{jh}}_{22}& {\mathrm{jh}}_{21}\\ h_{12}& h_{11}& {\mathrm{jh}}_{11}& -{\mathrm{jh}}_{12}\\ h_{22}& h_{21}& {\mathrm{jh}}_{21}& {-\mathrm{jh}}_{22}\end{array}\right]---\left(10\right)$

2, four antenna coding forms:

For obtaining the diffusion matrix of four antennas coding, at first define transition matrix C ₁～C ₄,

$C_1=\left[\begin{array}{cccc}0& 1& 0& 0\\ -1& 0& 0& 0\\ 0& 0& 0& 1\\ 0& 0& -1& 0\end{array}\right],$ $C_2=\left[\begin{array}{cccc}0& j& 0& 0\\ j& 0& 0& 0\\ 0& 0& 0& j\\ 0& 0& j& 0\end{array}\right],$ $C_3=\left[\begin{array}{cccc}0& 0& 1& 0\\ 0& 0& 0& -1\\ -1& 0& 0& 0\\ 0& 1& 0& 0\end{array}\right],$ $C_4=\left[\begin{array}{cccc}0& 0& j& 0\\ 0& 0& 0& -j\\ j& 0& 0& 0\\ 0& -j& 0& 0\end{array}\right]$

Further, diffusion matrix is specially:

$A_1=\frac{1}{2}{C}_1=\frac{1}{2}\left[\begin{array}{cccc}0& 1& 0& 0\\ -1& 0& 0& 0\\ 0& 0& 0& 1\\ 0& 0& -1& 0\end{array}\right],$ $A_2=\frac{1}{2}{C}_2=\frac{1}{2}\left[\begin{array}{cccc}0& j& 0& 0\\ j& 0& 0& 0\\ 0& 0& 0& j\\ 0& 0& j& 0\end{array}\right],$

$A_3=\frac{1}{2}{C}_3=\frac{1}{2}\left[\begin{array}{cccc}0& 0& 1& 0\\ 0& 0& 0& -1\\ -1& 0& 0& 0\\ 0& 1& 0& 0\end{array}\right],$ $A_4=\frac{1}{2}{C}_4=\frac{1}{2}\left[\begin{array}{cccc}0& 0& j& 0\\ 0& 0& 0& -j\\ j& 0& 0& 0\\ 0& -j& 0& 0\end{array}\right],$

$A_5=\frac{1}{2}{I}_4=\frac{1}{2}\left[\begin{array}{cccc}1& 0& 0& 0\\ 0& 1& 0& 0\\ 0& 0& 1& 0\\ 0& 0& 0& 1\end{array}\right],$ $A_6=\frac{1}{2}{C}_1\×C_2=\frac{1}{2}\left[\begin{array}{cccc}j& 0& 0& 0\\ 0& -j& 0& 0\\ 0& 0& j& 0\\ 0& 0& 0& -j\end{array}\right],$

$A_7=\frac{1}{2}{C}_1\×C_3=\frac{1}{2}\left[\begin{array}{cccc}0& 0& 0& -1\\ 0& 0& -1& 0\\ 0& 1& 0& 0\\ 1& 0& 0& 0\end{array}\right],$ $A_8=\frac{1}{2}{C}_1\×C_4=\frac{1}{2}\left[\begin{array}{cccc}0& 0& 0& -j\\ 0& 0& -j& 0\\ 0& -j& 0& 0\\ -j& 0& 0& 0\end{array}\right],$

$A_9=\frac{1}{2}{C}_2\×C_3=\frac{1}{2}\left[\begin{array}{cccc}0& 0& 0& -j\\ 0& 0& j& 0\\ 0& j& 0& 0\\ -j& 0& 0& 0\end{array}\right],$ $A_{10}=\frac{1}{2}{C}_2\×C_4=\frac{1}{2}\left[\begin{array}{cccc}0& 0& 0& 1\\ 0& 0& -1& 0\\ 0& 1& 0& 0\\ -1& 0& 0& 0\end{array}\right],$

$A_{11}=\frac{1}{2}{C}_3\×C_4=\frac{1}{2}\left[\begin{array}{cccc}j& 0& 0& 0\\ 0& j& 0& 0\\ 0& 0& -j& 0\\ 0& 0& 0& -j\end{array}\right],$ $A_{12}=\frac{1}{2}{C}_1\×C_2\×C_3=\frac{1}{2}\left[\begin{array}{cccc}0& 0& j& 0\\ 0& 0& 0& j\\ -j& 0& 0& 0\\ 0& -j& 0& 0\end{array}\right],$

$A_{13}=\frac{1}{2}{C}_1\×C_2\×C_4=\frac{1}{2}\left[\begin{array}{cccc}0& 0& -1& 0\\ 0& 0& 0& -1\\ -1& 0& 0& 0\\ 0& -1& 0& 0\end{array}\right],$ $A_{14}=\frac{1}{2}{C}_1\×C_3\×C_4=\frac{1}{2}\left[\begin{array}{cccc}0& j& 0& 0\\ -j& 0& 0& 0\\ 0& 0& 0& -j\\ 0& 0& j& 0\end{array}\right],$

$A_{15}=\frac{1}{2}{C}_2\×C_3\×C_4=\frac{1}{2}\left[\begin{array}{cccc}0& -1& 0& 0\\ -1& 0& 0& 0\\ 0& 0& 0& 1\\ 0& 0& 1& 0\end{array}\right],$ $A_{16}=\frac{1}{2}{C}_1\×C_2\×C_3\×C_4=\frac{1}{2}\left[\begin{array}{cccc}-1& 0& 0& 0\\ 0& 1& 0& 0\\ 0& 0& 1& 0\\ 0& 0& 0& -1\end{array}\right]$

Thereby obtain four antenna coding forms:

$X_4=\frac{1}{2}\left[\begin{array}{cccc}{x}_5+j{x}_6+{\mathrm{jx}}_{11}-x_{16}& x_1+{\mathrm{jx}}_2+{\mathrm{jx}}_{14}-x_{15}& x_3+j{x}_4+{\mathrm{jx}}_{12}-x_{13}& -x_7-{\mathrm{jx}}_8-{\mathrm{jx}}_9+x_{10}\\ -x_1+{\mathrm{jx}}_2-{\mathrm{jx}}_{14}-x_{15}& x_5-{\mathrm{jx}}_6+{\mathrm{jx}}_{11}+x_{16}& -x_7-j{x}_8+{\mathrm{jx}}_9-x_{10}& -x_3-{\mathrm{jx}}_4+{\mathrm{jx}}_{12}-x_{13}\\ -x_3+{\mathrm{jx}}_4-{\mathrm{jx}}_{12}-x_{13}& x_7-{\mathrm{jx}}_8+{\mathrm{jx}}_9+x_{10}& x_5+{\mathrm{jx}}_6-{\mathrm{jx}}_{11}+x_{16}& x_1+j{x}_2+{\mathrm{jx}}_{14}+x_{15}\\ x_7-{\mathrm{jx}}_8-{\mathrm{jx}}_9-x_{10}& x_3-{\mathrm{jx}}_4-{\mathrm{jx}}_{12}-x_{13}& -x_1+{\mathrm{jx}}_2-{\mathrm{jx}}_{14}+x_{15}& x_5-{\mathrm{jx}}_6-{\mathrm{jx}}_{11}-x_{16}\end{array}\right]---\left(11\right)$

Further, the dimension that can release based on Clifford algebraically is 2 ^LThe orthogonal basis set of matrices, have 2 ^2LIndividual, the MMSE that can constitute eight antennas detects the optimum code form.

Again single current Adaptive Modulation and Coding transmission plan is set forth below:

When system adopts the MMSE optimum code that obtains according to the encoding scheme in the inventive method to transmit, can obtain as drawing a conclusion by the calculating to equivalent channel: signal to noise ratio is identical after the detection of different transmission symbols, and the symbol performance that promptly experiences each antenna transmission is identical.

Fig. 5 is the overall transfer block diagram that detects the multi-aerial transmission system of optimum code based on MMSE of the present invention, if in Frequency Division Duplexing (FDD) (FDD) closed loop transmission system, transmitting terminal obtains equivalent channel by the channel information that obtains the receiving terminal feedback by the equivalent channel building method, and then definite transmission modulation coding mode, when using coding form of the present invention, because every symbol transmission performance is in full accord, so can handle with unified rate control strategy.If in time division duplex (TDD) system, transmitting terminal can obtain transmitting channel information by channel reciprocity, and then obtain equivalent channel matrix, and can determine the single current modulation coding mode thus.

Fig. 6 is as the base station model schematic diagram of transmitting terminal in the multi-aerial transmission system that detects optimum code based on MMSE of the present invention.As shown in Figure 6, be example with descending transmission link here, transmission system of the present invention comprise transmission policy and pairing as transmitting terminal the base station and as the user terminal of receiving terminal.Wherein, as the base station component model of transmitting terminal, comprise channel extraction module, Adaptive Modulation and Coding module, channel coding module, modulation module, Space Time Coding module and sending module.Wherein,

Described channel extraction module is for the FDD system, and this module has the function of extracting the receiving terminal feedback channel information, and for the TDD system, this module has the function of extracting channel information from the ascending channel detecting result.

Described Adaptive Modulation and Coding module is the nucleus module of Adaptive Transmission, from the channel extraction module, extract channel information, carry out the equivalent channel matrix structure, then have and calculate the function that single current detects the back Signal to Interference plus Noise Ratio, and have the function of selecting modulation coding mode (MCS) by the maximum principle of throughput.

Described channel coding module and modulation module carry out corresponding operating according to the MCS information of determining in the described Adaptive Modulation and Coding module.

Described Space Time Coding module is handled when the coding form of utilize determining is carried out sky at last by sending module symbol never with sending on the physics antenna.

Correspondingly, as the user terminal of receiving terminal, its model constitutes as shown in Figure 7 in the transmission system of the present invention, and it mainly comprises channel feedback module (FDD system), equivalent channel constructing module, MMSE linearity test module and demodulation decoding module.Wherein,

Described channel feedback module (supposing to be used for the FDD system) is applicable to the FDD system, is used for the channel information that the receiving terminal channel estimating obtains is later on sent to transmitting terminal by closed-loop feedback manner.

The channel matrix that described equivalent channel constructing module obtains by channel estimating according to formula (3) constructs the equivalent channel matrix suc as formula (2).

Described MMSE detection module utilizes equivalent channel matrix to carry out the MMSE linearity test.

Described modulation module is finished by the symbol after detecting to the processing capacity that the transmission bit information is estimated.

In other embodiments, also the Adaptive Modulation and Coding module can be arranged at receiving terminal, thereby bring in the selection of finishing MCS by reception, at this moment, one MCS feedback module need be set, be used for the selected MCS of Adaptive Modulation and Coding module is fed back to transmitting terminal, encode by transmitting terminal.

Multi-antenna transmission method and system based on the low-complicacy self-adaptive transmission of the present invention, compare with H-BLAST with traditional multiplex transmission system V-BLAST, should be in transmission course based on the transmission system of MMSE optimum code, use an encoder to produce data flow, then handle and send from different antennae by Space Time Coding, can think that each systematic bits all experiences all transmit antennas, so the system transmissions that has under the low situation of chnnel coding and code check can obtain obvious diversity gain, not only diversity gain is arranged with respect to the H-BLAST system, for the V-BLAST system, diversity gain is also fairly obvious.Simultaneously,, therefore can obtain unified MCS by the Adaptive Modulation and Coding algorithm because distinct symbols can obtain SINR after the identical detection, and then the operation of the single encoded device of control transmitting terminal.Than this, the data of experience different antennae obtain SINR after the different detections under the V-BLAST system, need make an uproar than carrying out corresponding union operation to Shinkansen after the detection of various flows if carry out Adaptive Transmission, and complexity is higher, and accuracy is also lost; The H-BLAST system can carry out the AMC operation respectively to the data flow of experience different antennae by wire rate control every day, but its complexity increasing and obviously improve with antenna number.

The present invention propose based on MMSE linearity test best performance space time coding scheme, its coding is made of the complete orthogonal basis set of matrices based on Clifford algebraically, coding form is clear simple, the unified use of system receiving terminal equivalent channel MMSE linear receiver.At configuration N _t(reception antenna N in the system of root transmitting antenna _r〉=N _t) be N with the transmission rate _tMultiplex rate transmission.By being analyzed, this coding equivalent channel obtains conclusion, using the transmission plan of this coding to carry out MMSE, to detect the back signal to noise ratio be identical for different transmission symbols, so just can be under the prerequisite of an encoded data stream application self-adapting code modulation module transmission exactly, than the V-BLAST system, the AMC operation does not need that each transport stream is done detection back signal to noise ratio and merges, only need do an adaptation rate control operation than this transmission plan of line adaptation rate control every day (PARC) system based on H-BLAST, system's computational complexity reduces greatly.

The above embodiment is the preferred embodiment that proves absolutely that the present invention lifts, and protection scope of the present invention is not limited thereto.Being equal to that those skilled in the art are done on basis of the present invention substitutes or conversion, all within protection scope of the present invention.Protection scope of the present invention is as the criterion with claims.

Claims (10)

1. the multi-antenna transmission method of low-complicacy self-adaptive transmission, this method detects optimum code based on MMSE, it is characterized in that, comprising:

Obtain channel information, according to described channel information, according to formula:

The structure equivalent channel matrix, and calculate single current by equivalent channel matrix and detect the back Signal to Interference plus Noise Ratio, select modulation coding mode MCS according to throughput-maximized principle, according to the MCS that selects transmission symbol is encoded and modulates by transmitting terminal, and after handling when utilizing the coding form of determining to carry out sky with symbol never with sending on the physics antenna;

Receiving terminal receives the symbol that described transmitting terminal sends, according to formula:

Estimate to construct the equivalent channel matrix of symbol experience by actual channel, and then utilize equivalent channel matrix to carry out the MMSE linearity test; Finish at last by the symbol after detecting to the processing that the transmission bit information is estimated;

Wherein: H _EqDimension is (N _r* N _t) * K, N _tBe transmitting antenna radical, N _rBe the reception antenna radical, and N _r〉=N _t, K is the number of complex symbol.

Expression N _t* N _tUnit matrix,

Represent straight product, H is N _r* N _tDimension channel fading matrix, A are the diffusion matrix of N * N dimension, N=N _t, vec (A) represents the matrix A vector quantization, order

Then

2. the multi-antenna transmission method of low-complicacy self-adaptive transmission according to claim 1, it is characterized in that, according to the described channel information that obtains, the structure equivalent channel matrix, and calculate single current by equivalent channel matrix and detect the back Signal to Interference plus Noise Ratio, select the step of modulation coding mode MCS to finish according to throughput-maximized principle by transmitting terminal or receiving terminal.

3. the multi-antenna transmission method of low-complicacy self-adaptive transmission according to claim 2, it is characterized in that, in tdd systems, the mode that described transmitting terminal obtains channel information is: extract described channel information and calculate equivalent channels information from the ascending channel detecting result by channel reciprocity.

4. the multi-antenna transmission method of low-complicacy self-adaptive transmission according to claim 2, it is characterized in that, in frequency division duplex system, the mode that described transmitting terminal obtains MCS is: obtain equivalent channel and select MCS by the channel information that obtains the receiving terminal feedback, perhaps select behind the MCS result to be fed back to transmitting terminal at receiving terminal.

5. the multi-antenna transmission method of low-complicacy self-adaptive transmission according to claim 1 is characterized in that, described MMSE detects the optimum code code word and represents by the form of linear diffuse code, promptly

And the diffusion matrix of coding is met the following conditions:

$A_i{A}_i^H=\frac{N}{K}{I}_N,$ And

$\mathrm{Trace}\left(A_i^H{A}_j\right)=0,$ $\∀i\≠j$

Wherein, [] ^HThe Matrix Conjugate transposition is got in expression, and matrix trace is asked in Trace () expression.

6. the multi-aerial transmission system of low-complicacy self-adaptive transmission, this system detects optimum code based on MMSE, comprises transmitting terminal and receiving terminal, it is characterized in that, and the transmitting terminal of the described MCS of having selection function comprises:

The channel extraction module is used to obtain channel information;

The Adaptive Modulation and Coding module is used to receive the channel information that described channel extraction module obtains, and carries out the equivalent channel structure, and calculates single current and detect the back Signal to Interference plus Noise Ratio, selects modulation coding mode MCS by throughput-maximized principle;

Channel coding module, the code rate information that is used for determining according to described Adaptive Modulation and Coding module is encoded to the transmission data bit;

Modulation module is used for the bit information behind the coding is modulated;

The Space Time Coding module is handled when the transmission symbol after being used to utilize definite coding form to modulation carries out sky;

Sending module, the symbol after handling when being used for sky is never with sending on the physics antenna;

Described receiving terminal comprises:

The equivalent channel constructing module is used for according to formula

Estimate to construct the equivalent channel matrix of symbol experience by actual channel;

Detection module is used to utilize described equivalent channel matrix to carry out the MMSE linearity test;

Demodulation module is used to finish by the symbol after detecting to the processing that the transmission bit information is estimated;

Wherein: H _EqDimension is (N _r* N _t) * K, N _tBe transmitting antenna radical, N _rBe the reception antenna radical, and N _r〉=N _t, K is the number of complex symbol.

Expression N _t* N _tUnit matrix, Represent straight product, H is N _r* N _tDimension channel fading matrix, A are the diffusion matrix of N * N dimension, N=N _t, vec (A) represents the matrix A vector quantization, order

Then

7. the multi-aerial transmission system of low-complicacy self-adaptive transmission according to claim 6 is characterized in that in frequency division duplex system, described receiving terminal also comprises:

The channel feedback module is used for the channel information that the receiving terminal channel estimating obtains is later on sent to transmitting terminal by closed-loop feedback manner;

The channel extraction module of described transmitting terminal is determined described channel information by the channel information that obtains the receiving terminal feedback.

8. the multi-aerial transmission system of low-complicacy self-adaptive transmission according to claim 6 is characterized in that in tdd systems, described transmitting terminal extracts described channel information by channel reciprocity from the ascending channel detecting result.

9. the multi-aerial transmission system of low-complicacy self-adaptive transmission according to claim 6 is characterized in that, described MMSE detects the optimum code code word and represents by the form of linear diffuse code, promptly

And the diffusion matrix of coding is met the following conditions:

$A_i{A}_i^H=\frac{N}{K}{I}_N,$ And

$\mathrm{Trace}\left(A_i^H{A}_j\right)=0,$ $\∀i\≠j$

Wherein, [] ^HConjugate transpose is got in expression, and matrix trace is asked in Trace () expression.

10. the multi-aerial transmission system of low-complicacy self-adaptive transmission, this system detects optimum code based on MMSE, comprises transmitting terminal and receiving terminal, it is characterized in that, and the receiving terminal of the described MCS of having selection function comprises:

The channel extraction module is used to obtain channel information;

The equivalent channel constructing module is used for according to formula

Estimate to construct the equivalent channel matrix of symbol experience by actual channel;

The Adaptive Modulation and Coding module is used for calculating single current according to equivalent channel and detects the back Signal to Interference plus Noise Ratio, selects modulation coding mode MCS by throughput-maximized principle;

The MCS feedback module is used for the MCS that the Adaptive Modulation and Coding module is selected is fed back to described transmitting terminal;

Detection module is used to utilize described equivalent channel matrix to carry out the MMSE linearity test;

Demodulation module is used to finish by the symbol after detecting to the processing that the transmission bit information is estimated;

Described transmitting terminal comprises:

Channel coding module is used for according to the code rate information of described MCS feedback module feedback the transmission data bit being encoded;

Modulation module is used for the bit information behind the coding is modulated;

The Space Time Coding module is handled when the transmission symbol after being used to utilize definite coding form to modulation carries out sky;

Sending module, the symbol after handling when being used for sky is never with sending on the physics antenna;

Wherein: H _EqDimension is (N _r* N _t) * K, N _tBe transmitting antenna radical, N _rBe the reception antenna radical, and N _r〉=N _t, K is the number of complex symbol.

Expression N _t* N _tUnit matrix,

Represent straight product, H is N _r* N _tDimension channel fading matrix, A are the diffusion matrix of N * N dimension, N=N _t, vec (A) represents the matrix A vector quantization, order

Then

Images