CN102075224B - MIMO system and signal receiving method and base station thereof - Google Patents

Abstract

The invention discloses a signal receiving method for a multi-user multi-cell multi-input multi-output (MIMO) system, which comprises the steps of: performing joint detection on a mobile station of a current cell of a base station and mobile stations which are in co-channel interference with the mobile station of the current cell in neighboring cells to obtain a receiving signal of the joint detection; calculating estimated data of each transmitted symbol of the mobile station of the current cell of the base station on the prior probability of each modulated constellation point according to the receiving signal of the joint detection; obtaining estimated data of each transmitted symbol of mobile stations of current cells of other base stations on the prior probability of each modulated constellation point; and aggregating the estimated data of each transmitted symbol of the mobile stations of the current cells of other base stations on the prior probability of each modulated constellation point, and the estimated data of each transmitted symbol of the mobile station of the current cell of the base station on the prior probability of each modulated constellation point to obtain judgment statistics of the receiving signal of the mobile station of the current cell, and performing detection judgment on the receiving signal.

Description

Mimo system and signal acceptance method thereof and base station

Technical field

The present invention relates to wireless communication technology field, specifically, relate to the many cell mimos of multi-user (Multiple-Input Multiple-Out-put) system and signal acceptance method and base station.

Background technology

Next generation mobile communication will provide higher message transmission rate and better service quality for the user, and power system capacity also will be greatly improved.Mimo system can adapt to this demand for development, has therefore obtained in recent years swift and violent development.Mimo system is by using respectively a plurality of antenna sending and receiving signals at transmitting terminal and receiving terminal, obtain space diversity and spatial multiplexing gain, thereby can increase considerably power system capacity under the condition that need not extra power consumption and bandwidth, significantly improve link quality, improve the availability of frequency spectrum, be applicable to audio frequency, the video multimedia business of two-forty.At present, point-to-point Single User MIMO systematic research reaches its maturity, and the multi-user MIMO system of point-to-multipoint (MU-MIMO) becomes new study hotspot.Fig. 1 illustrates the schematic diagram of multi-user MIMO system.For example, in the WLAN (wireless local area network) (WLAN) and cellular communication system of reality, communicate by letter simultaneously with a plurality of users usually in a base station, and the user has one or more antenna, and the base station has many antennas.Multiuser MIMO has lot of advantages: the diversity gain that many antennas bring can improve performance of BER, the spatial multiplexing gain of many antennas can enlarge the throughput of system, the directive gain that many antennas bring can be from dividing multi-user on the space, thereby eliminates inter-user interference.In the cellular communication system of reality, often adopt many residential quarters framework processed, and from many cell mimos of formation multi-user system.

in many cell mimos of multi-user systems, owing to adopting unified channeling and quadrature multiple access access scheme in each residential quarter, as frequency division multiple access (Frequency Division MultipleAccess, FDMA), single-carrier frequency division multiple access (Single-Carrier Frequency DivisionMultiple Access, SC-FDMA), time division multiple access (Time Division MultipleAccess, TDMA), interference in the residential quarter is commonly considered as negligible, therefore the common road of minizone disturbs (Co-Channel Interference, CCI) become a principal element of restriction system performance.The common road of minizone disturbs two interference of transmitting terminal because using same frequency range to cause that are in different districts.The interference processing method of traditional elimination CCI mainly relies on wireless resource distributing techniques, such as well-designed, the accurate power of channeling pattern is controlled, the distribution of spreading code accurately.But above conventional art may reduce the spectrum efficiency that can reach, and also may cause the inhibition of unsuitable CCI.

Based on the capacity analysis of information theory to multicell network, the reception technique that adopts cooperation between base stations to excavate the enhancing of system's latent capacity is suggested.The simplest cooperation between base stations is that a central processing node (Central Processing Unit is arranged in supposing the system, CPU) process and coordinate each base station, yet this framework based on CPU has a plurality of defectives: central processing node is a potential failure node, thereby whole system is easily paralysed; Moreover because the algorithm complexity of Multiuser Detection (Multi-User Detection, MUD) is affected by the number of users purpose mainly, therefore having a central processing node can increase potential excessive computation burden and huge interactive information flow.

The existing algorithm relevant to the signal reception of many cell mimos of multi-user system up-link, comprise alone family, single residential quarter (Single-cell Single-user) detection algorithm, be that the detection algorithm of non-cooperation is (with linear zero forcing algorithm (Linear Zero Forcing, LZF) be representative) and maximum likelihood algorithm (Maximum Likelihood, ML).Below we introduce respectively this several algorithms.

1) the non-cooperative detection algorithm in alone family, single residential quarter

Alone family, single residential quarter detection algorithm refers to adopt in each base station certain algorithm to carry out alone family and detects, the user's who is in it other residential quarter of disturbing in common road who receives signal, as noise processed, namely do not considered the user's that common road disturbs signal by simply.This class algorithm does not use the collaboration communication between the base station, take linear zero forcing algorithm (LZF) as representative, can be briefly described as follows:

Under the quasistatic fading channel, the signal phasor that receiver t receives constantly can be expressed as:

r _t＝Hx _t+n _t (1)

R wherein _tExpression n _{R * 1}The reception signal phasor, H is n _R* n _TThe dimension channel response matrix, x _tN _{T * 1}The transmitted signal vector, n _tN _R* 1 AWGN noise vector, its each component are that average is σ zero, that variance is ²Separate normally distributed random variable.The purpose of LZF algorithm is: at first detect the transmitted signal of certain one deck, then offset the interference that this layer signal causes from other layer, successive iteration is completed the detection of whole signal phasor at last.Order

Expression nature ordinal number 1,2 ..., n _TCertain arrange, the flow process of LZF algorithm can be described below:

Initialization: i=1; G ₁=H ⁺

Iterative process:

$s_i=\arg \underset{j\&NotElement;\{{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HSA00000410822600061.png,HSA00000410822600071.png"\; state="\{\{state\}\}">s</figure-callout>}}_1,{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HSA00000410822600071.png,HSA00000410822600072.png"\; state="\{\{state\}\}">s</figure-callout>}}_2,\&CenterDot;\&CenterDot;\&CenterDot;,s_{i-1}\}}{\min }{\left|\right|{\left(G_i\right)}_j\left|\right|}^2---\left(2\right)$

$W_{s_i}={\left(G_i\right)}_{s_i}---\left(3\right)$

$y_{s_i}=W_{s_i}{r}_i---\left(4\right)$

${\hat{x}}_{s_i}=Q\left(y_{s_i}\right)---\left(5\right)$

$r_{i+1}=r_1-{\hat{x}}_{s_i}{\left(H\right)}_{s_i}^T---\left(6\right)$

$G_{i+1}=H_{\stackrel{\&OverBar;}{s_i}}^{+}---\left(7\right)$

i＝i+1 (8)

In formula, H ⁺Expression Moore-Penrose generalized inverse;

Expression makes s ₁, s ₂... s _iClassify the generalized inverse of 0 matrix that obtains as; (G _i) _jRepresenting matrix G _iJ capable; Q () function representation carries out the hard decision demodulation according to planisphere to detection signal.

Due to the impact of having ignored common road and disturb CCI, this class alone family detection algorithm has lower complexity, but performance is also relatively poor.

2) maximum likelihood algorithm (ML)

Maximum likelihood joint detection algorithm (ML) can be described below: to (1) formula, the algorithm employing minimizes (9) formula and detects:

$m\left(x_t\right|r_t,H)=\underset{i=1}{\overset{n_R}{\mathrm{\&Sigma;}}}{|r_{t_i}-H_i{x}_t|}^2---\left(9\right)$

Wherein

Expression r _iI (i=1,2 ... n _R) individual component; H _iThe i of expression H (i=1,2 ... n _R) OK, be 1 * n _TVector; x _tN _T* 1 transmitted signal vector.Decoding based on (9) formula is a very complicated process, particularly works as n _RWhen larger.Under the multi-user MIMO system environment, when consideration is total to affecting of road interference, need to adopt the joint maximum likelihood detection, at this moment need to know the channel matrix information of base station and all common road interference users.The decoding that the ball decoding algorithm that in practice, many employings have reduced complexity helps solve the ML detector, and the radius of a ball can carry out according to signal to noise ratio environment at that time the self adaptation adjusting.

Summary of the invention

The technical problem that the present invention will solve is to provide a kind of mimo system and signal acceptance method and base station, make than present detection algorithm, can solve preferably the problem that common road disturbs, elevator system performance significantly, and have acceptable complexity.

According to a first aspect of the present invention, a kind of signal acceptance method for many cell mimos of multi-user system is provided, comprise: carry out joint-detection to being in this residential quarter travelling carriage the travelling carriage that disturbs in common road in this residential quarter travelling carriage of base station and adjacent cell, obtain the reception signal of joint-detection; Send symbol about the data estimator of the prior probability of each modulation constellation points according to each of this residential quarter travelling carriage of the reception calculated signals base station of joint-detection; Each of this residential quarter travelling carriage that obtains other base station sends symbol about the data estimator of the prior probability of each modulation constellation points; Each of this residential quarter travelling carriage of other base station sent symbol to be sent symbol about each of this residential quarter travelling carriage of the data estimator of the prior probability of each modulation constellation points and base station and carries out joint account about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of this residential quarter travelling carriage, detect to received signal judgement.

By signal acceptance method of the present invention, can eliminate the impact that common road disturbs, reach the purpose that strengthens receptivity.

Preferably, sending symbol according to each of this residential quarter travelling carriage of the reception calculated signals base station of joint-detection comprises about the step of the data estimator of the prior probability of each modulation constellation points: send symbol about the data estimator of the prior probability of each modulation constellation points according to the reception signal of joint-detection based on each of this residential quarter travelling carriage of PDA algorithm calculation base station.

By using the PDA algorithm, simplified finding the solution of posterior probability, make the method have acceptable complexity in improving performance.

Preferably, each of this residential quarter travelling carriage that obtains other base station sends symbol and comprise about the step of the data estimator of the prior probability of each modulation constellation points: the interactive mode of the client-server that adopts between each base station carries out collaboration communication, sends symbol about the data estimator of the prior probability of each modulation constellation points with each of this residential quarter travelling carriage of obtaining other base station.

The base station is as client, and each base station can receive that many parts oneself need the user's of detection soft decision information data, are benefited adjacent residential quarter.

Preferably, signal acceptance method also comprises:

The base station is obtained channel condition information G by channel estimating ^k:

$G^k=[H_k^k,H_{{\mathrm{\&alpha;}}_1}^k,\&CenterDot;\&CenterDot;\&CenterDot;,H_{{\mathrm{\&alpha;}}_{C_u}}^k]$

Right

With

Revise according to following formula:

${\hat{H}}_k^k={\mathrm{\&beta;}}_k{H}_k^k+\sqrt{1-{\mathrm{\&beta;}}_k^2}{E}_k$

${\hat{H}}_{{\mathrm{\&alpha;}}_i}^k{{=\mathrm{\&beta;}}_{\mathrm{\&alpha;}}}_i{H}_{{\mathrm{\&alpha;}}_i}^k+\sqrt{1-{\mathrm{\&beta;}}_{{\mathrm{\&alpha;}}_i}^2}{E}_{{\mathrm{\&alpha;}}_i}$

Wherein,

Be the channel condition information between k base station and this residential quarter travelling carriage,

For And BS _kBetween M _b* M _uChannel matrix, M _bThe antenna number of expression base station, M _uThe antenna number of expression travelling carriage,

Represent α _iIndividual travelling carriage, i=1 ... C _u, C _uRepresent that effective and this residential quarter travelling carriage is in the mobile number of units of common road interference, BS _kRepresent k base station, k=1 ... N _b, N _bExpression base station number altogether, E _kExpression

Variance, Expression

Variance, β _kWith

The quality of expression channel estimating.

By channel matrix is revised, correct the non-perfect problem of channel condition information that channel estimating obtains.

Preferably, adopt following formula to send symbol to each of this residential quarter travelling carriage of obtaining other base station and send symbol about each of this residential quarter travelling carriage of the data estimator of the prior probability of each modulation constellation points and base station and carry out joint account about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of this residential quarter travelling carriage:

$P_m\left(s_t\right|y_{\mathrm{coop}})=P_m\left(s_t\right|y^k)\underset{j=1}{\overset{C_b}{\mathrm{\&Pi;}}}{P}_m\left(s_t\right|y^{{\mathrm{\&beta;}}_j}),$

And the soft decision information that obtains is carried out normalized:

$P_m{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}=\frac{P_m\left(s_t\right|y_{\mathrm{coop}})}{\underset{m}{\mathrm{\&Sigma;}}{P}_m\left(s_t\right|y_{\mathrm{coop}})},$

Wherein, y _CoopRepresentative is used for the reception signal of cooperation between base stations, y ^kThe reception signal that represents k base station, k=1 ... N _b, N _bExpression base station number altogether,

Represent β _jIndividual base station with acknowledge(ment) signal, j=1 ..., C _b, C _bBe contiguous base station number, S _tExpression sends symbol, t=1,2..., M _u(C _u+ 1), M _uThe antenna number of expression travelling carriage, C _uRepresent that effective and this residential quarter travelling carriage is in the mobile number of units of common road interference, P _m(s _t| y) expression is to s _t=a _m, m=1,2 ... the estimation of the Prior Probability of the transmission symbol of M, a _mM element in the set of expression modulation constellation points, P _m(s _t| y _Coop) the synthetic soft decision information of expression.

Preferably, detecting to received signal judgement comprises:

To each transmission symbol S _tCarry out conclusive judgement, draw

Wherein, m ' satisfies following formula:

$m^{\&prime;}=\arg \underset{d=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;,M}{\max }\left\{P_d{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}\right\}.$

According to a second aspect of the present invention, a kind of base station for many cell mimos of multi-user system is provided, comprise: checkout gear, be used for this residential quarter travelling carriage and the adjacent cell of base station are carried out joint-detection with the travelling carriage that this residential quarter travelling carriage is in the interference of common road, obtain the reception signal of joint-detection; Calculation element, each that is used for according to this residential quarter travelling carriage of the reception calculated signals base station of joint-detection sends symbol about the data estimator of the prior probability of each modulation constellation points; Interactive device, each of this residential quarter travelling carriage that be used for to obtain other base station sends symbol about the data estimator of the prior probability of each modulation constellation points; Judgment device, being used for that each of this residential quarter travelling carriage of other base station sent symbol sends symbol about each of this residential quarter travelling carriage of the data estimator of the prior probability of each modulation constellation points and base station and carries out joint account about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of this residential quarter travelling carriage, detect to received signal judgement.

By the base station for many cell mimos of multi-user system of the present invention, can eliminate the impact that common road disturbs, reach the purpose that strengthens receptivity.

Preferably, calculation element sends symbol about the data estimator of the prior probability of each modulation constellation points according to the reception signal of joint-detection based on each of PDA algorithm calculating book residential quarter travelling carriage.

By using the PDA algorithm, simplified finding the solution of posterior probability, have acceptable complexity in improving performance.

Preferably, interactive device carries out collaboration communication by interactive mode and other base station of the client-server that adopts between each base station, send symbol about the data estimator of the prior probability of each modulation constellation points with each of this residential quarter travelling carriage of obtaining other base station.

Interactive device mainly makes adjacent residential quarter be benefited.The base station is as client, and each base station can receive that many parts oneself need the user's of detection soft decision information data.

Preferably, this base station also comprises: channel estimating apparatus obtains channel condition information G to the base station by channel estimating ^k:

$G^k=[H_k^k,H_{{\mathrm{\&alpha;}}_1}^k,\&CenterDot;\&CenterDot;\&CenterDot;,H_{{\mathrm{\&alpha;}}_{C_u}}^k]$

Right With Revise according to following formula:

${\hat{H}}_k^k={\mathrm{\&beta;}}_k{H}_k^k+\sqrt{1-{\mathrm{\&beta;}}_k^2}{E}_k$

${\hat{H}}_{{\mathrm{\&alpha;}}_i}^k{{=\mathrm{\&beta;}}_{\mathrm{\&alpha;}}}_i{H}_{{\mathrm{\&alpha;}}_i}^k+\sqrt{1-{\mathrm{\&beta;}}_{{\mathrm{\&alpha;}}_i}^2}{E}_{{\mathrm{\&alpha;}}_i}$

Wherein,

Be the channel condition information between k base station and this residential quarter travelling carriage,

For

And BS _kBetween M _b* M _uChannel matrix, M _bThe antenna number of expression base station, M _uThe antenna number of expression travelling carriage,

Represent α _iIndividual travelling carriage, i=1 ... C _u, C _uRepresent that effective and this residential quarter travelling carriage is in the mobile number of units of common road interference, BS _kRepresent k base station, k=1 ... N _b, N _bExpression base station number altogether, E _kExpression Variance,

Expression Variance, β _kWith The quality of expression channel estimating.

By channel matrix is revised, correct the non-perfect problem of channel condition information that channel estimating obtains.

Preferably, judgment device adopts following formula to send symbol to each relevant to this residential quarter travelling carriage that obtains from other base station to carry out joint account about each transmission symbol of the data estimator of the prior probability of each modulation constellation points and this residential quarter travelling carriage of base station of calculating about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of this residential quarter travelling carriage:

$P_m\left(s_t\right|y_{\mathrm{coop}})=P_m\left(s_t\right|y^k)\underset{j=1}{\overset{C_b}{\mathrm{\&Pi;}}}{P}_m\left(s_t\right|y^{{\mathrm{\&beta;}}_j}),$

And the soft decision information that obtains is carried out normalized:

$P_m{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}=\frac{P_m\left(s_t\right|y_{\mathrm{coop}})}{\underset{m}{\mathrm{\&Sigma;}}{P}_m\left(s_t\right|y_{\mathrm{coop}})}$

Wherein, y _CoopRepresentative is used for the reception signal of cooperation between base stations, y ^kThe reception signal that represents k base station, k=1 ... N _b, N _bExpression base station number altogether, Represent β _jIndividual base station with acknowledge(ment) signal, j=1 ..., C _b, C _bBe contiguous base station number, S _tExpression sends symbol, t=1,2..., M _u(C _u+ 1), M _uThe antenna number of expression travelling carriage, C _uRepresent that effective and this residential quarter travelling carriage is in the mobile number of units of common road interference, P _m(s _t| y) expression is to s _t=a _m, m=1,2 ... the estimation of the Prior Probability of the transmission symbol of M, a _mM element in the set of expression modulation constellation points, P _m(s _t| y _Coop) the synthetic soft decision information of expression.

Preferably, judgment device is to each transmission symbol s _tCarry out conclusive judgement, draw

Wherein, m ' satisfies following formula:

$m^{\&prime;}=\arg \underset{d=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;,M}{\max }\left\{P_d{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}\right\}$

According to a third aspect of the present invention, a kind of many cell mimos of multi-user systems is provided, comprise the base station as second aspect present invention.

Than prior art, the problem disturbed of road altogether in resolution system preferably, elevator system performance significantly, and have acceptable complexity.

Description of drawings

Fig. 1 shows the schematic diagram of multi-user MIMO system.

Fig. 2 shows the flow chart according to an embodiment of the signal acceptance method for many cell mimos of multi-user systems of the present invention.

Fig. 3 shows the flow chart according to another embodiment of the signal acceptance method for many cell mimos of multi-user systems of the present invention.

Fig. 4 shows the block diagram according to an embodiment of the base station for many cell mimos of multi-user systems of the present invention.

Fig. 5 shows the block diagram according to another embodiment of the base station for many cell mimos of multi-user systems of the present invention.

Fig. 6 shows the hexagon topological diagram according to an embodiment of the many residential quarters of multi-user of the present invention (MIMO) system.

Fig. 7 shows without the Performance Ratio of the PDA of soft merging and ML joint detection algorithm, distributed PDA algorithm, alone family, single residential quarter LZF algorithm, alone family ML and PDA circle.

Fig. 8 shows the distributed PDA algorithm performance analysis under the different channels estimated quality.

Fig. 9 shows the distributed PDA convergence of algorithm character analysis with soft merging.

Embodiment

With reference to the accompanying drawings the present invention is described more fully, exemplary embodiment of the present invention wherein is described.

The invention provides a kind of signal acceptance method of many cell mimos of the multi-user system up-link based on distributed probabilities data association algorithm and cooperation between base stations, be applied in many cell mimos of multi-user systems.In one embodiment of the invention, each base station adopts the PDA algorithm to carry out joint-detection to being in this community user the user who disturbs in common road in this community user and adjacent cell, obtain under the condition of current reception signal, each sends symbol about the estimation of the prior probability of each modulation constellation points, again by the collaboration communication between the base station, the prior probability data that exchange obtains, at last carry out the merging of soft information at each base station end, obtain decision statistics, thereby complete the detection that receives signal.

Probability data is assisted (Probabilistic Data Association, PDA) method is used to target following at first, after be developed into a kind of so-called best soft decision method maximum a posteriori probability (Maximum A Posteriori that can be used for substituting, MAP) the low complex degree scheme of decoder/detector/equalizer, and be generalized to gradually in the Multiuser Detection of CDMA and mimo system.

The main thought of PDA method is: according to central-limit theorem with some variablees and be approximately gaussian variable.the PDA method is used as the current detection symbol as stochastic variable, other layer interference is approximated to Gaussian noise, by this approximate, calculate with the average of gaussian variable coupling and variance and then obtain the conditional probability of current detection symbol according to the prior information of other layer symbol, this conditional probability is again as the prior information that detects other layer symbol, the conditional probability of each layer symbol is able to continuous iteration renewal like this, if certain detection signal log-likelihood ratio (Log-Likelihood-Ratios that twice iteration obtains, LLRs) less than a threshold value, the detection that this signal is described restrains.

The PDA method has the following advantages: first, it is a kind of natural soft output soft-output algorithm (Soft-Input-Soft-Output, SISO), be highly suitable for the merging of convolution code, Turbo code, low density parity check code (Low Density Parity Check, LDPC); The second, it can reach the performance of the Multiuser Detection of near-optimization, particularly under CDMA (CodeDivision Multiple Access) system; The 3rd, it has lower complexity, generally is no more than O (L3) when adopting BPSK (Binary Phase Shift Keying) modulation, and L represents number of transmit antennas in mimo system or the number of users in cdma system here; The 4th, under the condition of the non-order loss of channel, number of transmit antennas or number of users are more, and the performance that system can reach is better.

The below introduces the PDA algorithm:

The core concept of PDA algorithm is the Gaussian approximation to noise and interlayer interference, this approximate finding the solution of simplifying posterior probability.The basic procedure of PDA algorithm:

Receive signal:

r＝Hx+n (10)

Wherein, x sends vector, and H is channel matrix, and n is the white Gaussian noise vector.

If m the symbol x of x _mBe the current detection symbol:

$r=h_m{x}_m+\underset{k\&NotEqual;m}{\mathrm{\&Sigma;}}{h}_k{x}_k+n---\left(11\right)$

Wherein, h _kRepresent the k row of channel matrix.

$w=\underset{k\&NotEqual;m}{\mathrm{\&Sigma;}}{h}_k{x}_k+n$

Wherein, w is by a gaussian variable n and several stochastic variables h _kx _kAddition forms.According to central-limit theorem, work as h _kx _kNumber when abundant, w trends towards Gaussian Profile.Average and covariance matrix are:

${\mathrm{\&mu;}}_w=E\{\underset{k\&NotEqual;m}{\mathrm{\&Sigma;}}{h}_k{x}_k+n\}=\underset{k\&NotEqual;m}{\mathrm{\&Sigma;}}E\left\{x_k\right\}{h}_k---\left(13\right)$

$R_w=E\left\{(w-{\mathrm{\&mu;}}_w){(w-{\mathrm{\&mu;}}_w)}^H\right\}=\underset{k\&NotEqual;m}{\mathrm{\&Sigma;}}\mathrm{Var}\left\{x_k\right\}{h}_k{h_k}^H+{\mathrm{\&sigma;}}_n^{2}I---\left(14\right)$

Each component of supposing w is Cyclic Symmetry, and namely the real part of random vector is identical with variance with distribution and average with imaginary part, and the posterior probability that can obtain the current detection symbol is:

$P{r}_l\left(a_j\right|r)=\frac{p\left(r\right|a_j)\mathrm{Pr}\left(a_j\right)}{p\left(r\right)}=c\&CenterDot;\exp (-{(r-a_j{h}_m-{\mathrm{\&mu;}}_w)}^H{R}_w^{-1}(r-a_j{h}_m-{\mathrm{\&mu;}}_w))---\left(15\right)$

A wherein _j∈ Q, Q are the modulation symbol set.

This probability can be used as x again when detecting other symbol _mPrior information calculate x _mAverage and variance.Iteration, restrain until all layers are launched symbol posterior probability so successively.

The accuracy of the Gaussian approximation in the PDA algorithm has considerable influence to algorithm performance, if number of transmit antennas or number of users are less, central-limit theorem will no longer be set up, and it is inaccurate that Gaussian approximation becomes, thereby can affect Algorithm Performance.Given this, the people such as Y.Jia has proposed a kind of CPDA (Complex formulation of the PDA) algorithm.Consider the complex signal model:

$\tilde{r}=\tilde{H}\&CenterDot;\tilde{x}+\tilde{n}---\left(16\right)$

Wherein:

$\tilde{r}={\left[R\right\{r^T\left\}I\right\{r^T\left\}\right]}^T$

$\tilde{x}={\left[R\right\{x^T\left\}I\right\{x^T\left\}\right]}^T$

$\tilde{n}={\left[R\right\{n^T\left\}I\right\{n^T\left\}\right]}^T---\left(17\right)$

$\tilde{H}=\left[\begin{array}{cc}R\left\{H\right\}& -I\left\{H\right\}\\ I\left\{H\right\}& R\left\{H\right\}\end{array}\right]$

R{}, I{} represent respectively and get real part and imaginary part.Therefore the scale of signal Candidate Set dwindles, real empty two the asymmetric problems of statistical property of the w in the time of need not considering iteration simultaneously.The CPDA algorithm adopts average, covariance matrix, pseudocovariance matrix to remove to portray the Gauss's vector that is similar to.The calculating of posterior probability is undertaken by following flow process:

v＝r-a _jh _m-μ _w (18)

$\mathrm{\&phi;}\left(a_j\right)=\exp (-\left\{\begin{array}{c}R\left\{v\right\}\\ I\left\{v\right\}\end{array}\right\}{\mathrm{\&Lambda;}}_j{\left\{\begin{array}{c}R\left\{v\right\}\\ I\left\{v\right\}\end{array}\right\}}^T)---\left(19\right)$

${\mathrm{\&Lambda;}}_j={\left(\begin{array}{cc}R\{R_w+K_w\}& -I\{R_w-K_w\}\\ I\{R_w+K_w\}& R\{R_w-K_w\}\end{array}\right)}^{-1}$

$\mathrm{Pr}\left(a_j\right|\tilde{r})=\frac{\mathrm{\&phi;}\left(a_j\right)}{\underset{a_j\&Element;Q}{\mathrm{\&Sigma;}}\mathrm{\&phi;}\left(a_j\right)}---\left(20\right)$

Fig. 2 shows the flow chart according to an embodiment of the signal acceptance method for many cell mimos of multi-user systems of the present invention, comprises the steps:

Step 202: carry out joint-detection to being in this residential quarter travelling carriage the travelling carriage that disturbs in common road in this residential quarter travelling carriage of base station and adjacent cell, obtain the reception signal of joint-detection;

Step 204: send symbol about the data estimator of the prior probability of each modulation constellation points according to each of this residential quarter travelling carriage of the reception calculated signals base station of joint-detection;

Step 206: each of this residential quarter travelling carriage that obtains other base station sends symbol about the data estimator of the prior probability of each modulation constellation points;

Step 208: each of this residential quarter travelling carriage of other base station sent symbol send symbol about each of this residential quarter travelling carriage of the data estimator of the prior probability of each modulation constellation points and base station and carry out joint account about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of this residential quarter travelling carriage, detect to received signal judgement.

By this signal acceptance method, can eliminate the impact that common road disturbs, reach the purpose that strengthens receptivity.

Fig. 3 shows the flow chart according to another embodiment of the signal acceptance method for many cell mimos of multi-user systems of the present invention.Be described in detail for each step below in conjunction with Fig. 3:

To specific many cell mimos of a multi-user system, arrange following parameter:

N _b: the residential quarter number of base station number altogether/altogether

N _u: mobile number of units altogether

K _i, i=1,2 ... N _b: the number of the travelling carriage of each residential quarter

M _b: the antenna number of base station (antenna number of supposing each base station is consistent)

M _u: the antenna number of travelling carriage (antenna number of supposing each travelling carriage is consistent)

C _u: effective and active user is in the mobile number of units that common road disturbs

C _b: contiguous base station number

Step 302 first to each base station, obtains all channel condition informations by channel estimating.

Step 304 is carried out joint-detection to being in this community user the user who disturbs in common road in this community user of this base station and adjacent cell, obtains the reception signal of joint-detection.If k (k=1 ... N _b) signal that receives of individual base station is:

y ^k＝G ^ks ^k+n ^k (21)

Wherein:

$G^k=[H_k^k,H_{{\mathrm{\&alpha;}}_1}^k,\&CenterDot;\&CenterDot;\&CenterDot;,H_{{\mathrm{\&alpha;}}_{C_u}}^k]---\left(22\right)$

For

And BS _kBetween M _b* M _uChannel matrix, i=1 ... C _u, k=1 ... N _b

For in the residential quarter

In travelling carriage The length that sends is M _uSignal vector, and each symbol comes from the constellation point set A that gesture is M={ α ₁, α ₂... α _M.Here s ^kBe expressed as T=1,2 ..., M _u(C _u+ 1).

n ^kFor length is M _bComplex value circle symmetrical Gaussian noise, average is 0, at BS _kThe covariance matrix at place is

Wherein

Be M _b* M _bUnit matrix.

According to one embodiment of present invention, right

With Revise according to following formula:

${\hat{H}}_k^k={\mathrm{\&beta;}}_k{H}_k^k+\sqrt{1-{\mathrm{\&beta;}}_k^2}{E}_k---\left(23\right)$

${\hat{H}}_{{\mathrm{\&alpha;}}_i}^k{{=\mathrm{\&beta;}}_{\mathrm{\&alpha;}}}_i{H}_{{\mathrm{\&alpha;}}_i}^k+\sqrt{1-{\mathrm{\&beta;}}_{{\mathrm{\&alpha;}}_i}^2}{E}_{{\mathrm{\&alpha;}}_i}---\left(24\right)$

β wherein _kAs

The quality of expression channel estimating can be supposed close to 1, but can not be greater than 1.By channel matrix is revised, correct the non-perfect problem of channel condition information that channel estimating obtains.

(21) formula can be rewritten as:

$y^k={\hat{G}}^k{s}^k+n^k---\left(25\right)$

Here Notice and work as β _kWith

Equal at 1 o'clock, the formula of above formula when having perfect channel estimating is consistent, therefore after algorithm steps all consider the perfect channel estimating that has, need to consider the situation of non-perfect channel estimating, only need to replace (21) formula with (25) formula and get final product.

Step 306 sends symbol about the data estimator of the prior probability of each modulation constellation points according to the reception signal of joint-detection based on each of this residential quarter travelling carriage of PDA algorithm calculation base station.Concrete steps are as follows:

A) work as M _u(C _u+ 1)≤M _bThe time

Consider base station BS _k, and will remove in subscript k formula below.Now with (21) formula again

Be written as:

$\tilde{y}=\tilde{s}+\tilde{n}=s_t{e}_t+\underset{l\&NotEqual;t}{\mathrm{\&Sigma;}}{s}_l{e}_l+\tilde{n}=s_t{e}_t+v_t---\left(26\right)$

Wherein Be coloured Gaussian noise, average is 0, and covariance is N ₀(G ^HG) ^-1, e _lBe a column vector, l element is 1, and other elements are all 0, v _tExpression is to signal s _tThe impact of interference noise, t wherein, l=1,2 ..., M _u(C _u+ 1).Each is sent symbol s _t, we calculate it under the condition of current reception signal by following alternative manner, and each sends symbol about the estimation P of the prior probability of each modulation constellation points _t, P wherein _tM element P _m(s _t| y) expression is to s _t=a _m, m=1,2 ... the estimation of the Prior Probability of M, a here _mM element in the set of expression modulation constellation points.

Suppose that all send symbol and have identical prior probability, be information source for waiting general distribution

Information source, iterative step is as follows:

I. initialization: initialization P _m(s _t| be y) evenly to distribute, for example

$\&ForAll;t=1,2,\&CenterDot;\&CenterDot;\&CenterDot;M_u(C_u+1),$ $\&ForAll;m=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;,M,$ Iteration count is set is

z＝1

Ii. the symbol subscript is set to t=1

Iii. based on current { P (l) } _{L ≠ t}, calculate according to following (27) to (33) formula

P _m(s _t| y), in order to substitute P _tIn element:

$\stackrel{\&OverBar;}{s_l}=\underset{m=1}{\overset{M}{\mathrm{\&Sigma;}}}{a}_m{P}_m\left(s_l\right|y)---\left(27\right)$

$V\left\{s_l\right\}=\underset{m=1}{\overset{M}{\mathrm{\&Sigma;}}}(a_m-\stackrel{\&OverBar;}{s_l}){(a_m-\stackrel{\&OverBar;}{s_l})}^{*}{P}_m\left(s_l\right|y)---\left(28\right)$

$U\left\{s_l\right\}=\underset{m=1}{\overset{M}{\mathrm{\&Sigma;}}}(a_m-\stackrel{\&OverBar;}{s_l}){(a_m-\stackrel{\&OverBar;}{s_l})}^T{P}_m\left(s_l\right|y)---\left(29\right)$

$w_m^{\left(t\right)}=\tilde{y}-a_m^{\left(t\right)}{e}_t-\underset{l\&NotEqual;t}{\mathrm{\&Sigma;}}\stackrel{\&OverBar;}{s_l}{e}_l---\left(30\right)$

Wherein,

Expression a _mBe assigned to s _t,

With

Represent respectively real and imaginary part.

If t＜M iv. _u(C _u+ 1), make t=t+1, forward step I ii to, otherwise, forward step v to.

If P v. _tRestrain, Perhaps iterations has surpassed maximum constraints, eventually

Stop this algorithm, otherwise, make z=z+1, forward step I i to.

B) work as M _u(C _u+ 1)＞M _bThe time

Again be written as (21) formula this moment:

$y=g_t{s}_t+\underset{l\&NotEqual;t}{\mathrm{\&Sigma;}}{g}_l{s}_l+n=g_t{s}_t+u_t---\left(34\right)$

G wherein _lBe G ^kIn l row, similar, the iterative step algorithm in adopting a) is also

Can obtain the estimated value P of required prior probability _t

By using the PDA algorithm, simplified finding the solution of posterior probability, make the method have acceptable complexity in improving performance.

The interactive mode of the unified client-server that step 308 adopts between each base station (Unified-Client-Server mode) carries out collaboration communication, sends symbol about the data estimator of the prior probability of each modulation constellation points with each of this residential quarter travelling carriage of obtaining other base station.Here, suppose all to adopt between each base station desirable fiber shaft network to be connected.The base station is as service end, the user that it can help the required common road, residential quarter of all cooperations to disturb, and send the soft decision information that obtains to the base station at all users place.

The base station is as client, and each base station can receive that many parts oneself need the user's of detection soft decision information data, are benefited adjacent residential quarter.

Step 310, adopt following formula to send symbol to each of this residential quarter travelling carriage of obtaining other base station and send symbol about each of this residential quarter travelling carriage of the data estimator of the prior probability of each modulation constellation points and base station and carry out joint account about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of this residential quarter travelling carriage:

$P_m\left(s_t\right|y_{\mathrm{coop}})=P_m\left(s_t\right|y^k)\underset{j=1}{\overset{C_b}{\mathrm{\&Pi;}}}{P}_m\left(s_t\right|y^{{\mathrm{\&beta;}}_j})---\left(35\right)$

Wherein, y _CoopRepresentative is used for the reception signal of cooperation between base stations, y ^kThe reception signal that represents k base station, k=1 ... N _b, N _bExpression base station number altogether,

Represent β _jIndividual base station with acknowledge(ment) signal, j=1 ..., C _b, C _bBe contiguous base station number.P _m(s _t| y _Coop) the synthetic soft decision information of expression.Again data are carried out normalized according to formula (36):

$P_m{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}=\frac{P_m\left(s_t\right|y_{\mathrm{coop}})}{\underset{m}{\mathrm{\&Sigma;}}{P}_m\left(s_t\right|y_{\mathrm{coop}})}---\left(36\right)$

Step 312 is to each transmission symbol s _tCarry out conclusive judgement, draw

Wherein m ' satisfies formula (37):

$m^{\&prime;}=\arg \underset{d=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;,M}{\max }\left\{P_d{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}\right\}---\left(37\right)$

Fig. 4 shows the block diagram according to an embodiment of the base station for many cell mimos of multi-user systems of the present invention.

As shown in Figure 4, base station 40 comprises: checkout gear 401, be used for this residential quarter travelling carriage and the adjacent cell of base station 40 are carried out joint-detection with the travelling carriage that this residential quarter travelling carriage is in the interference of common road, and obtain the reception signal of joint-detection; Calculation element 402, each that is used for according to this residential quarter travelling carriage of the reception calculated signals base station 40 of checkout gear 401 joint-detection sends symbol about the data estimator of the prior probability of each modulation constellation points; Interactive device 403, each of this residential quarter travelling carriage that is used for obtaining from the calculation element 402 of other base station other base station sends symbol about the data estimator of the prior probability of each modulation constellation points; Judgment device 404, being used for that each of this residential quarter travelling carriage of other base station sent symbol sends symbol about each of this residential quarter travelling carriage of the data estimator of the prior probability of each modulation constellation points and base station 40 and carries out joint account about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of this residential quarter travelling carriage, detect to received signal judgement.

By the base station 40 for many cell mimos of multi-user system of the present invention, can eliminate the impact that common road disturbs, reach the purpose that strengthens receptivity.

Fig. 5 shows the block diagram according to an embodiment of the base station for many cell mimos of multi-user systems of the present invention.

As shown in Figure 5, identical in checkout gear 401, calculation element 402, interactive device 403 and judgment device 404 and Fig. 4 no longer described in detail herein.Difference is, base station 50 shown in Figure 5 also comprises: channel estimating apparatus 505 is used for that channel estimating is carried out in the base station and obtains channel condition information G ^k:

$G^k=[H_k^k,H_{{\mathrm{\&alpha;}}_1}^k,\&CenterDot;\&CenterDot;\&CenterDot;,H_{{\mathrm{\&alpha;}}_{C_u}}^k]---\left(22\right)$

According to one embodiment of present invention, right With

Revise according to following formula:

${\hat{H}}_k^k={\mathrm{\&beta;}}_k{H}_k^k+\sqrt{1-{\mathrm{\&beta;}}_k^2}{E}_k---\left(23\right)$

${\hat{H}}_{{\mathrm{\&alpha;}}_i}^k{{=\mathrm{\&beta;}}_{\mathrm{\&alpha;}}}_i{H}_{{\mathrm{\&alpha;}}_i}^k+\sqrt{1-{\mathrm{\&beta;}}_{{\mathrm{\&alpha;}}_i}^2}{E}_{{\mathrm{\&alpha;}}_i}---\left(24\right)$

Wherein,

Be the channel condition information between k base station and this residential quarter travelling carriage,

For

And BS _kBetween M _b* M _uThe letter matrix, M _bThe antenna number of expression base station, M _uThe antenna number of expression travelling carriage,

Represent α _iIndividual travelling carriage, i=1 ... C _u, C _uRepresent that effective and this residential quarter travelling carriage is in the mobile number of units of common road interference, BS _kRepresent k base station, k=1 ... N _b, N _bExpression base station number altogether, E _kExpression

Variance, Expression Variance, β _kWith

The quality of expression channel estimating.

By channel matrix is revised, correct the non-perfect problem of channel condition information that channel estimating obtains.

According to one embodiment of the present of invention, calculation element 402 sends symbol about the data estimator of the prior probability of each modulation constellation points according to the reception signal of joint-detection based on each of PDA algorithm calculating book residential quarter travelling carriage.

By using the PDA algorithm, simplified finding the solution of posterior probability, have acceptable complexity in improving performance.

According to one embodiment of the present of invention, interactive device 403 carries out collaboration communication by interactive mode and other base station of the client-server that adopts between each base station, send symbol about the data estimator of the prior probability of each modulation constellation points with each of this residential quarter travelling carriage of obtaining other base station.

Interactive device 403 mainly makes adjacent residential quarter be benefited.The base station is as client, and each base station can receive that many parts oneself need the user's of detection soft decision information data.

According to one embodiment of the present of invention, judgment device 404 adopts following formula to send symbol to each relevant to this residential quarter travelling carriage that obtains from other base station to carry out joint account about each transmission symbol of the data estimator of the prior probability of each modulation constellation points and this residential quarter travelling carriage of base station of calculating about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of this residential quarter travelling carriage:

$P_m\left(s_t\right|y_{\mathrm{coop}})=P_m\left(s_t\right|y^k)\underset{j=1}{\overset{C_b}{\mathrm{\&Pi;}}}{P}_m\left(s_t\right|y^{{\mathrm{\&beta;}}_j}),---\left(35\right)$

And the soft decision information that obtains is carried out normalized:

$P_m{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}=\frac{P_m\left(s_t\right|y_{\mathrm{coop}})}{\underset{m}{\mathrm{\&Sigma;}}{P}_m\left(s_t\right|y_{\mathrm{coop}})}---\left(36\right)$

Wherein, y _CoopRepresentative is used for the reception signal of cooperation between base stations, y ^kThe reception signal that represents k base station, k=1 ... N _b, N _bExpression base station number altogether,

Represent β _jIndividual base station with acknowledge(ment) signal, j=1 ..., C _b, C _bBe contiguous base station number, S _tExpression sends symbol, t=1,2..., M _u(C _u+ 1), M _uThe antenna number of expression travelling carriage, C _uRepresent that effective and this residential quarter travelling carriage is in the mobile number of units of common road interference, P _m(s _t| y) expression is to s _t=a _m, m=1,2 ... the estimation of the Prior Probability of the transmission symbol of M, a _mM element in the set of expression modulation constellation points, P _m(s _t| y _Coop) the synthetic soft decision information of expression.

Judgment device 404 is to each transmission symbol s _tCarry out conclusive judgement, draw Wherein, m ' satisfies following formula:

$m^{\&prime;}=\arg \underset{d=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;,M}{\max }\left\{P_d{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}\right\}---\left(37\right).$

Example of the present invention is described below, and setting parameter does not affect generality.

Fig. 6 shows the hexagon topological diagram according to an embodiment of the many residential quarters of multi-user of the present invention (MIMO) system.As shown in Figure 6, this mobile cellular system has for example 19 residential quarters, and there is for example base station BS each residential quarter ₀To BS ₁₈Mobile station MS for example ₀To MS ₁₈, the below introduces the signal acceptance method in this multi-user's multi-cell system.

Multi-user's multi-cell system shown in Figure 6 supposes that in figure, unified frequency reuse plan and identical quadrature multiple access access scheme are adopted in each residential quarter, and MS ₀To MS ₁₈These 19 travelling carriages have been assigned with same frequency range.Suppose simultaneously following parameter: N _b=19, M _u=2, M _b=8, maximum iteration time I=5.The present invention carries out according to following steps for this example:

1, to these 19 base stations, obtain all channel condition informations by channel estimating.Carry out joint-detection to being in this community user the user who disturbs in common road in this community user of this base station and adjacent cell again, obtain the reception signal of joint-detection.For example, BS ₀With joint-detection MS ₀, MS ₂, MS ₃, MS ₄, BS ₁With joint-detection MS ₁, MS ₈, MS ₂, MS ₀Deng.

2, all are received signal and adopt the probability calculation criterion in the PDA algorithm to carry out iterative computation, draw under the condition of current reception signal, each sends symbol about the estimation of the prior probability of each modulation constellation points, specific algorithm comparator algorithm step 2.

3, adopt the interactive mode of unified client-server to carry out collaboration communication between each base station, the data of exchange prior probability obtained in the previous step.Here, suppose all to adopt between each base station desirable fiber shaft network to be connected.For example, BS ₀Can detect his own required user MS ₀Priori probability information, and detect simultaneously MS ₂, MS ₃, MS ₄Priori probability information send base station BS to ₂, BS ₃, BS ₄On the other hand, in order to help MS ₀Make judgement, the base station BS around it ₀, BS ₁, BS ₅, BS ₆Can detect it, and the soft information that will obtain

Be transferred to base station BS ₀, all these probability datas can send base station BS to ₀, i.e. MS ₀The base station of the residential quarter at place.Therefore, BS ₀, BS ₁, BS ₅, BS ₆To MS ₀The judgement of acknowledge(ment) signal all brought into play effect.

4, the joint account of soft information is carried out separately in each base station, draws the decision statistics of own required user's reception signal, thereby detects to received signal judgement.Concrete algorithm steps carries out according to formula (35), formula (36), formula (37).

In order to show the signal acceptance method based on many cell mimos of multi-user system up-link of distributed probabilities data association algorithm and cooperation between base stations that proposes in the present invention, with the Performance Ratio of existing detection algorithm, we have done emulation experiment, experiment is for many cell mimos of multi-user system model of hexagon topology set forth above, and done following concrete the processing: modulation system adopts QPSK; Channel adopts the flat Rayleigh fading channel; The average equivalent signal-to-noise ratio of each reception antenna is designated as SNR=10log ₁₀(E{||G _s|| ²/ M _b}/E{||n|| ²); Subchannel matrix between travelling carriage and base station is chosen as the independent identically distributed complex value Gaussian random variable of 0 average, unit variance; 1000 receiving symbol vectors of every generation regenerate new channel matrix; Each noise vector n ^kElement obey 0 average, variance is N ₀Independent identically distributed gaussian variable; For each travelling carriage, the channel estimating quality keeps always, and namely parameter beta is unified.In addition, in view of M _u(C _u+ 1)≤M _bAnd M _u(C _u+ 1)＞M _bEither way show close performance, and the former has lower computation complexity, so adopt the former model to get final product in our emulation.

Definition interference density ρ is the channel gain ratio that is in user with the user of this residential quarter demand of the interference of common road, is:

I=1 ... C _u, wherein || || _FExpression Frobenius norm.

Emulation experiment has been carried out respectively simulation analysis for the boundary without ML and PDA under the ML of soft merging and PDA joint detection algorithm, distributed PDA algorithm, alone family, single residential quarter LZF algorithm, the noiseless condition in alone family, has compared performance.As can be seen from Figure 7, under identical interference density ρ, the distributed PDA algorithm that comprises soft information merging that the present invention proposes has more excellent performance with respect to other several algorithms, and when interference density ρ got larger value (ρ=0.8), distributed PDA algorithm still showed the more excellent performance of other several algorithms relatively.

In addition, emulation experiment has been carried out respectively simulation analysis for the iteration convergence character of non-perfect channel estimating condition and distributed PDA algorithm, can find out from Fig. 8 as a result, Fig. 9 of obtaining, the quality of channel estimating has certain impact to Algorithm Performance, and the iteration convergence character of algorithm is better.

Signal acceptance method proposed by the invention is that a kind of distributed probabilities data association algorithm that adopts communicates by letter to eliminate the impact of CCI with cooperation between base stations, thereby improves the signal acceptance method of systematic function.Than present detection algorithm, the method can preferably resolve the problem of disturbing, larger lifting systematic function, and have an acceptable complexity, collaboration communication between the base station and the merging of soft information have been characterized in utilizing, and PDA algorithm high-performance and low complex degree, can be similar to the performance that reaches this optimal algorithm of maximum a posteriori probability and have lower complexity and convergence rate faster.

Description of the invention provides for example with for the purpose of describing, and is not exhaustively or limit the invention to disclosed form.Many modifications and variations are obvious for the ordinary skill in the art.Selecting and describing embodiment is for better explanation principle of the present invention and practical application, thereby and makes those of ordinary skill in the art can understand the various embodiment with various modifications that the present invention's design is suitable for special-purpose.

Claims (9)

1. signal acceptance method that is used for many cell mimos of multi-user system comprises:

Carry out joint-detection to being in described this residential quarter travelling carriage the travelling carriage that disturbs in common road in this residential quarter travelling carriage of base station and adjacent cell, obtain the reception signal of joint-detection;

Send symbol about the data estimator of the prior probability of each modulation constellation points according to each of described this residential quarter travelling carriage of the reception calculated signals described base station of described joint-detection;

Each of described this residential quarter travelling carriage that obtains other base station sends symbol about the data estimator of the prior probability of each modulation constellation points;

Each of described this residential quarter travelling carriage of described other base station sent symbol to be sent symbol about each of described this residential quarter travelling carriage of the data estimator of the prior probability of each modulation constellation points and described base station and carries out joint account about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of described this residential quarter travelling carriage, described reception signal is detected judgement;

Wherein, adopt following formula to send symbol to each of described this residential quarter travelling carriage of obtaining other base station and send symbol about each of described this residential quarter travelling carriage of the data estimator of the prior probability of each modulation constellation points and described base station and carry out joint account about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of described this residential quarter travelling carriage:

$P_m\left(s_t\right|y_{\mathrm{coop}})=P_m\left(s_t\right|y^k)\underset{j=1}{\overset{C_b}{\mathrm{\&Pi;}}}{P}_m\left(s_t\right|y^{{\mathrm{\&beta;}}_j}),$

And the soft decision information that obtains is carried out normalized:

$P_m{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}=\frac{P_m\left(s_t\right|y_{\mathrm{coop}})}{\underset{m}{\mathrm{\&Sigma;}}{P}_m\left(s_t\right|y_{\mathrm{coop}})},$

Wherein, y _CoopRepresentative is used for the reception signal of cooperation between base stations, y ^kThe reception signal that represents k base station, k=1 ... N _b, N _bExpression base station number altogether,

Represent β _jIndividual base station with acknowledge(ment) signal, j=1 ..., C _b, C _bBe contiguous base station number, s _tExpression sends symbol, t=1,2..., M _u(C _u+ 1), M _uThe antenna number of expression travelling carriage, C _uRepresent that effective and this residential quarter travelling carriage is in the mobile number of units of common road interference, P _m(s _t| y) expression is to s _t=a _m, m=1,2 ... the estimation of the Prior Probability of the transmission symbol of M, a _mM element in the set of expression modulation constellation points, P _m(s _t| y _Coop) the synthetic soft decision information of expression;

Described reception signal is detected judgement to be comprised:

To each transmission symbol s _tCarry out conclusive judgement, draw

Wherein, m ' satisfies following formula: $m^{\&prime;}=\arg \underset{d=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;,M}{\max }\left\{P_d{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}\right\}.$

2. signal acceptance method as claimed in claim 1, it is characterized in that, each of described this residential quarter travelling carriage of described reception calculated signals described base station according to described joint-detection sends symbol and comprises about the step of the data estimator of the prior probability of each modulation constellation points:

Each of described this residential quarter travelling carriage of calculating described base station according to the described reception signal of joint-detection based on the PDA algorithm sends symbol about the data estimator of the prior probability of each modulation constellation points.

3. signal acceptance method as claimed in claim 1, it is characterized in that, each of described this residential quarter travelling carriage of other base station of described acquisition sends symbol and comprise about the step of the data estimator of the prior probability of each modulation constellation points: the interactive mode of the client-server that adopts between each base station carries out collaboration communication, sends symbol about the data estimator of the prior probability of each modulation constellation points with each of described this residential quarter travelling carriage of obtaining described other base station.

4. signal acceptance method as claimed in claim 1, is characterized in that, also comprises:

Described base station is obtained channel condition information G by channel estimating ^k:

$G^k=[H_k^k,H_{{\mathrm{\&alpha;}}_1}^k,\&CenterDot;\&CenterDot;\&CenterDot;,H_{{\mathrm{\&alpha;}}_{C_u}}^k]$

Right

With

Revise according to following formula:

${\hat{H}}_k^k={\mathrm{\&beta;}}_k{H}_k^k+\sqrt{1-{\mathrm{\&beta;}}_k^2}{E}_k$

${\hat{H}}_{{\mathrm{\&alpha;}}_i}^k={\mathrm{\&beta;}}_{{\mathrm{\&alpha;}}_i}{H}_{{\mathrm{\&alpha;}}_i}^k+\sqrt{1-{\mathrm{\&beta;}}_{{\mathrm{\&alpha;}}_i}^2}{E}_{{\mathrm{\&alpha;}}_i}$

Wherein,

Be the channel condition information between k base station and this residential quarter travelling carriage,

For

And BS _kBetween M _b* M _uChannel matrix, M _bThe antenna number of expression base station, M _uThe antenna number of expression travelling carriage,

Represent α _iIndividual travelling carriage, i=1 ... C _u, C _uRepresent that effective and this residential quarter travelling carriage is in the mobile number of units of common road interference, BS _kRepresent k base station, k=1 ... N _b, N _bExpression base station number altogether, E _kExpression

Variance,

Expression

Variance, β _kWith

The quality of expression channel estimating.

5. base station that is used for many cell mimos of multi-user system comprises:

Checkout gear is used for this residential quarter travelling carriage and the adjacent cell of base station are carried out joint-detection with the travelling carriage that described this residential quarter travelling carriage is in the interference of common road, obtains the reception signal of joint-detection;

Calculation element, each that is used for according to described this residential quarter travelling carriage of the reception calculated signals described base station of described joint-detection sends symbol about the data estimator of the prior probability of each modulation constellation points;

Interactive device, each of described this residential quarter travelling carriage that be used for to obtain other base station sends symbol about the data estimator of the prior probability of each modulation constellation points;

Judgment device, being used for that each of described this residential quarter travelling carriage of described other base station sent symbol sends symbol about each of described this residential quarter travelling carriage of the data estimator of the prior probability of each modulation constellation points and described base station and carries out joint account about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of described this residential quarter travelling carriage, described reception signal is detected judgement;

Wherein, described judgment device adopts following formula to send symbol to each relevant to described this residential quarter travelling carriage that obtains from other base station to carry out joint account about each transmission symbol of the data estimator of the prior probability of each modulation constellation points and this residential quarter travelling carriage of base station of calculating about the data estimator of the prior probability of each modulation constellation points, obtain the decision statistics of the reception signal of described this residential quarter travelling carriage:

$P_m\left(s_t\right|y_{\mathrm{coop}})=P_m\left(s_t\right|y^k)\underset{j=1}{\overset{C_b}{\mathrm{\&Pi;}}}{P}_m\left(s_t\right|y^{{\mathrm{\&beta;}}_j}),$

And the soft decision information that obtains is carried out normalized:

$P_m{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}=\frac{P_m\left(s_t\right|y_{\mathrm{coop}})}{\underset{m}{\mathrm{\&Sigma;}}{P}_m\left(s_t\right|y_{\mathrm{coop}})}$

Wherein, y _CoopRepresentative is used for the reception signal of cooperation between base stations, y ^kThe reception signal that represents k base station, k=1 ... N _b, N _bExpression base station number altogether, Represent β _iIndividual base station with acknowledge(ment) signal, j=1 ..., C _b, C _bBe contiguous base station number, s _tExpression sends symbol, t=1,2..., M _u(C _u+ 1), M _uThe antenna number of expression travelling carriage, C _uRepresent that effective and this residential quarter travelling carriage is in the mobile number of units of common road interference, P _m(s _t| y) expression is to s _t=a _m, m=1,2 ... the estimation of the Prior Probability of the transmission symbol of M, a _mM element in the set of expression modulation constellation points, P _m(s _t| y _Coop) the synthetic soft decision information of expression;

Described judgment device is to each transmission symbol s _tCarry out conclusive judgement, draw

Wherein, m ' satisfies following formula: $m^{\&prime;}=\arg \underset{d=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;,M}{\max }\left\{P_d{\left(s_t\right|y_{\mathrm{coop}})}_{\mathrm{norm}}\right\}.$

6. base station as claimed in claim 5, is characterized in that, described calculation element calculates each transmission symbol of described this residential quarter travelling carriage about the data estimator of the prior probability of each modulation constellation points according to the described reception signal of joint-detection based on the PDA algorithm.

7. base station as claimed in claim 5, it is characterized in that, described interactive device carries out collaboration communication by interactive mode and other base station of the client-server that adopts between each base station, send symbol about the data estimator of the prior probability of each modulation constellation points with each of described this residential quarter travelling carriage of obtaining described other base station.

8. base station as claimed in claim 5, is characterized in that, also comprises:

Channel estimating apparatus obtains channel condition information G to described base station by channel estimating ^k:

$G^k=[H_k^k,H_{{\mathrm{\&alpha;}}_1}^k,\&CenterDot;\&CenterDot;\&CenterDot;,H_{{\mathrm{\&alpha;}}_{C_u}}^k]$

Right With

Revise according to following formula:

${\hat{H}}_k^k={\mathrm{\&beta;}}_k{H}_k^k+\sqrt{1-{\mathrm{\&beta;}}_k^2}{E}_k$

${\hat{H}}_{{\mathrm{\&alpha;}}_i}^k={\mathrm{\&beta;}}_{a_i}{H}_{{\mathrm{\&alpha;}}_i}^k+\sqrt{1-{\mathrm{\&beta;}}_{a_i}^2}{E}_{{\mathrm{\&alpha;}}_i}$

Wherein,

Be the channel condition information between k base station and this residential quarter travelling carriage,

For

And BS _kBetween M _b* M _uChannel matrix, M _bThe antenna number of expression base station, M _uThe antenna number of expression travelling carriage,

Represent α _iIndividual travelling carriage, i=1 ... C _u, C _uRepresent that effective and this residential quarter travelling carriage is in the mobile number of units of common road interference, BS _kRepresent k base station, k=1 ... N _b, N _bExpression base station number altogether, E _kExpression

Variance,

Expression Variance, β _kWith

The quality of expression channel estimating.

9. many cell mimos of multi-user system, comprise base station as described in any one in claim 5-8.

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