CN102130753B - Method and system for processing signal - Google Patents

Abstract

The present invention relates to a method and a system for processing signal. The method and system for orthogonalized beamforming in multiple user multiple input multiple output (MU-MIMO) communication systems are presented. Aspects of the method and system include an iterative method for computing a plurality of beamforming matrices in a MU-MIMO system. A transmitting station, such as an access point (AP) for example, may use computed channel estimates, and/or singular vector matrices, to compute orthogonal beamforming matrices. The computed orthogonal beamforming matrices may be used to generate a plurality of signals, which may be concurrently transmitted to the plurality of user devices.

Description

A kind of method and system of processing signals

Technical field

The present invention relates to communication network, more particularly, relate to a kind of method and system forming for multi-user's multiple-input and multiple-output (MU-MIMO) system orthogonal beams.

Background technology

Mobile communication has changed people's communication mode, and mobile phone has developed into the requisite part of daily life from luxury goods.Now, the use of mobile phone determined by social condition, and pining down of region or technology not.When voice connect the basic need met communication, and mobile voice continues more deeply while being penetrated in daily life, and mobile Internet becomes next step target of mobile communication.Mobile Internet can become the generally source of daily information at any time, and facilitates mobile access these data in general ground natural by becoming.

Single User MIMO (SU-MIMO) system is launched a plurality of data flow by a plurality of NTX transmitting antennas in use cell site simultaneously and is realized high-speed radiocommunication.The data flow of transmitting is being used the receiving station place of a plurality of NRX antennas to receive simultaneously.Shannon capacity (shannon capacity) refers to the maximum data rate of communicating by letter between cell site and receiving station.In Single User MIMO system, can reach Shannon capacity by the formation of closed loop wave beam, link circuit self-adapting and/or serial interference elimination (SIC) technology.

MU-MIMO system is compared with SU-MIMO system, and cell site is used a plurality of NTX transmitting antennas to launch a plurality of data flow simultaneously, and described data flow is received by a plurality of receiving stations simultaneously, and wherein each receiving station adopts NRX reception antenna.With respect to SU-MIMO system, MU-MIMO system is used the transmitting antenna of greater number to support more data flow to launch simultaneously.

Compare the follow-up aspect that will set forth by reference to the accompanying drawings of the present invention, other limitation of prior art and drawback are apparent for the person of ordinary skill of the art.

Summary of the invention

The invention provides a kind of method and system forming for multi-user's multiple-input and multiple-output (MU-MIMO) communication system orthogonal beams, in conjunction with at least one width accompanying drawing, carried out representing fully and describing, and obtained in the claims more complete elaboration.

According on the one hand, a kind of method of processing signals is provided, described method comprises:

By one or more processors and/or circuit, carry out:

Based on a plurality of channel estimate matrixs, channels associated matrix and/or eigenvectors matrix, calculate a plurality of beam forming matrixs in multiuser mimo system;

Based on described a plurality of beam forming matrixs, calculate a plurality of orthogonal matrixes;

Based on described a plurality of beam forming matrixs and described a plurality of orthogonal matrix, determine that a plurality of orthogonal beams form matrix.

Preferably, described method further comprises based on described a plurality of beam forming matrixs and generates a plurality of intermediary matrixs.

Preferably, described method further comprises and selects one of described a plurality of intermediary matrixs and described a plurality of beam forming matrixs corresponding selected one.

Preferably, the matrix product of the strategic point of described selected close (Hermitian) transformation matrix of described selected and described a plurality of intermediary matrixs of described a plurality of intermediary matrixs equals the matrix product of the close transformation matrix of strategic point of selected of described correspondence of selected and described a plurality of beam forming matrixs of the described correspondence of described a plurality of beam forming matrixs.

Preferably, described method further comprises based on Cholesky decomposition method (cholesky decomposition) and generates described selected of described a plurality of intermediary matrixs.

Preferably, selected one of described a plurality of orthogonal matrixes equates with the inverse matrix of described selected of described a plurality of intermediary matrixs.

Preferably, described method further comprises selected of described correspondence of described selected and described a plurality of beam forming matrixs based on described a plurality of orthogonal matrixes, calculates described a plurality of orthogonal beams and forms of matrixes.

Preferably, described method further comprises a plurality of pre-coding matrixes that calculate for described multiuser mimo system.

Preferably, each of described a plurality of pre-coding matrixes is corresponding at least one of a plurality of users in described multiuser mimo system.

Preferably, described method further comprises that based on described a plurality of pre-coding matrixes and described a plurality of orthogonal beams, forming matrix generates a plurality of quadrature precoding beam forming matrixs.

According to one side, a kind of system of processing signals comprises:

One or more circuit, calculate a plurality of beam forming matrixs in multiuser mimo system based on a plurality of channel estimate matrixs, channels associated matrix and/or eigenvectors matrix;

Described one or more circuit calculates a plurality of orthogonal matrixes based on described a plurality of beam forming matrixs;

Described one or more circuit determines that based on described a plurality of beam forming matrixs and described a plurality of orthogonal matrix a plurality of orthogonal beams form matrix.

Preferably, described one or more circuit generates a plurality of intermediary matrixs based on described a plurality of beam forming matrixs.

Preferably, described one or more circuit is selected one of described a plurality of intermediary matrixs and described a plurality of beam forming matrixs corresponding selected one.

Preferably, the matrix product of the close transformation matrix of strategic point of described selected of described selected and described a plurality of intermediary matrixs of described a plurality of intermediary matrixs equals the matrix product of the close transformation matrix of strategic point of selected of described correspondence of selected and described a plurality of beam forming matrixs of the described correspondence of described a plurality of beam forming matrixs.

Preferably, described one or more circuit is based on described selected one of the described a plurality of intermediary matrixs of Cholesky decomposition method generation.

Preferably, selected one of described a plurality of orthogonal matrixes equates with the inverse matrix of described selected of described a plurality of intermediary matrixs.

Preferably, selected of the described correspondence of described selected one and the described a plurality of beam forming matrixs of described one or more circuit based on described a plurality of orthogonal matrixes, calculates described a plurality of orthogonal beams and forms of matrixes.

Preferably, described one or more circuit calculates a plurality of pre-coding matrixes for described multiuser mimo system.

Preferably, each of described a plurality of pre-coding matrixes is corresponding at least one of a plurality of users in described multiuser mimo system.

Preferably, described one or more circuit generates a plurality of quadrature precoding beam forming matrixs based on described a plurality of pre-coding matrixes and described a plurality of orthogonal beams formation matrix.

Below in connection with accompanying drawing, specific embodiment is described in detail, to help to understand various advantage of the present invention, various aspects and character of innovation.

Accompanying drawing explanation

Fig. 1 is the block diagram for the demonstration MIMO transceiver of one embodiment of the invention employing;

Fig. 2 is the block diagram for the demonstration multi-user MIMO system of one embodiment of the invention employing;

Fig. 3 is the flow chart according to the example steps forming for MU-MIMO communication system orthogonal beams of one embodiment of the invention;

Fig. 4 is the flow chart in the elaboration MU-MIMO communication system according to one embodiment of the invention with the example steps that the orthogonal beams of precoding forms.

Embodiment

The invention provides the method and system forming for multi-user's multiple-input and multiple-output (MU-MIMO) communication system orthogonal beams.Various embodiments of the present invention can, by adopting alternative manner to calculate a plurality of beam forming matrixs in MU-MIMO system, increase the data rate capacity of communicating by letter in MU-MIMO system.One embodiment of the present of invention Zhong， cell site such as access point (AP) can adopt beam forming matrix to generate the signal of transmitting simultaneously, and described signal can be emitted to a plurality of subscriber equipmenies simultaneously.The beam forming matrix of each calculating is quadrature.Orthogonal beams for each calculating forms matrix, can be corresponding subscriber devices compute unique user channel capacity value.Calculate a plurality of calculated unique user channel capacity value sums and can obtain overall channel capacity.The orthogonal beams of calculating forms matrix also can adopt precoding.With respect to other method, the employing of orthogonal beams formation matrix can increase the data rate capacity of the communication channel of communicating by letter for MU-MIMO system.

Fig. 1 is the block diagram for the demonstration MIMO transmitting-receiving station of one embodiment of the invention employing.Fig. 1 shows wireless receiving and dispatching station 102 and a plurality of antenna 132a...132n.Wireless receiving and dispatching station 102 is demonstration Wireless Telecom Equipment, can be used for access point (AP) equipment or station (STA) equipment of wireless communication system.A plurality of antenna 132a...132n make wireless receiving and dispatching station 102 and/or receive signal, for example radio frequency (RF) signal through radio communication media transmitting.Wireless receiving and dispatching station 102 shown in Fig. 1 also can be depicted as and comprise one or more transmitting antennas, and described transmitting antenna connects reflector 116 and one or more reception antenna, and described reception antenna connects receiver 118 without loss of generality.

Demonstration wireless receiving and dispatching station comprises processor 112, memory 114, receiver 118, transmits and receives (T/R) switch 120 and antenna array 122.Antenna array 122 is selected one or more antenna 132a...132n, the transmitting of 102 places and/or reception antenna at wireless receiving and dispatching station.T/R switch 120 makes antenna array 122 can communicate to connect reflector 116 or receiver 118.When T/R switch 120 is when 122 of reflector 116 and antenna arrays are realized communication connection, can adopt selected antenna 132a...132n to transmit.When T/R switch 120 is when 122 of receiver 118 and antenna arrays are realized communication connection, can adopt selected antenna 132a...132n to receive signal.

Reflector 116 can generate signal, and this signal can be launched by selected antenna 132a...132n.Reflector 116 generates signal by carrying out encoding function, signal modulation and/or signal modulation.In various embodiments of the present invention, reflector 116 uses precoding and/or beam-forming technology to generate signal.

Receiver 118 can be processed the signal receiving through selected antenna 132a...132n.Receiver 118 by executive signal amplify, signal demodulation and/or decoding function, and based on receiving signal generated data.In various embodiments of the present invention, receiver 118 can generated data, and reflector 116 can adopt described data to realize precoding and/or the wave beam that generates signal forms.

Processor 112 can generate transmitting data and/or process and receive data.The data that reflector 116 can adopt processor 112 to generate generate signal.Processor 112 can be processed the data that receiver 118 generates.In various embodiments of the present invention, in Node B, processor 112 can be processed data and the generation coefficient data that receiver 118 receives, and the wave beam that reflector 116 can adopt described coefficient data to realize precoding and/or generation signal forms.Coefficient data is stored in memory 114.

In various embodiments of the present invention, in AP, processor 112 is for a plurality of beam forming matrixs of iterative computation and/or corresponding matched filter matrix.Signal and/or feedback information, calculating beamforming matrix and/or the matched filter matrix of processor 112 in AP based on receiving from one or more STA.Beam forming matrix and/or matched filter matrix are stored in memory 114.Matched filter matrix is sent to reflector 116 by processor 112, or is extracted from memory 114 by reflector 116.Reflector 116 adopts beam forming matrix to generate signal, to transmit matched filter matrix to STA.The signal generating is launched through transmitting antenna 132a...132n simultaneously.

Fig. 2 is the block diagram for the demonstration multi-user MIMO system of one embodiment of the invention employing.Fig. 2 show there is a plurality of transmitting antenna 222a, 222b ..., the AP 202 of 222n, the STA 232a with a plurality of antenna 242a...242n, the STA 232b with a plurality of antenna 244a...244n, the STA 232n with a plurality of antenna 246a...246n and communication medium 252.STA 232a, STA 232b ..., the quantity of STA232n represents by quantity K.Antenna 242a...242n, 244a...244n and/or 246a...246n are respectively used to the signal transmitting at STA 232a, 232b and 232n place and/or receive.Wherein the antenna amount at each STA place is represented by quantity M.Yet, in various embodiments of the present invention, can determine separately the antenna amount at given STA place.AP 202 comprises that a plurality of wave beams form piece F ₁212a, F ₂212b and F _k212n.Transmitting antenna 222a, 222b ..., the quantity of 222n represents by quantity N.

In one embodiment of the present of invention, AP 202 can launch a plurality of K group data stream (X simultaneously ₁, X ₂..., X _k).In one embodiment of the present of invention, each set of streams Xi represents a plurality of L data flow.As shown in Figure 2, every group data stream inputs to a corresponding wave beam and forms piece.For example, as shown in Figure 2, connection data stream group X ₁as forming piece F to wave beam ₁the input of 212a, connection data stream group X ₂as forming piece F to wave beam ₂the input of 212b ..., connection data stream group X _kas forming piece F to wave beam _kthe input of 212n.Wave beam form piece 212a, 212b ..., 212n each can connect a plurality of transmitting antenna 222a, 222b ..., 222n.Wave beam form piece 212a, 212b ..., 212n each adopt corresponding beam forming matrix F ₁, F ₂..., F _kgenerate a plurality of transmit signal chains, then through a plurality of N transmitting antenna 222a, 222b ..., 222n launches simultaneously.Transmit and propagate on communication medium 252.In one embodiment of the present of invention, AP 202 can launch the signal generating from a plurality of KL data flow simultaneously.In various embodiments of the present invention, N >=KL.

In one embodiment of the present of invention, the signal of simultaneously launching from AP 202 after communication medium 252 is propagated STA 232a by a plurality of M antenna 242a ..., 242n reception.The communication channel of AP 202 to STA 232a can be by channel estimate matrix H ₁characterize the signal of this matrix based on launch through a plurality of N transmitting antennas and receive through a plurality of M reception antennas simultaneously.The signal of simultaneously launching from AP 202 after communication medium 252 is propagated STA 232a through a plurality of M antenna 244a ..., 244n reception.The communication channel of AP 202 to STA232b can be by channel estimate matrix H ₂characterize.The signal of simultaneously launching from AP 202 after communication medium 252 is propagated STA 232n through a plurality of M antenna 246a ..., 246n reception.The communication channel of AP 202 to STA 232n can be by channel estimate matrix H _kcharacterize.In various embodiments of the present invention, M >=L.

In one embodiment of the present of invention, each STA adopts corresponding matched filter matrix W _iselectivity receives K group data stream X ₁, X ₂..., X _kone of middle correspondence.For example, STA 232a adopts matched filter matrix W ₁selectivity receiving data stream group X ₁, STA 232b adopts matched filter matrix W ₂selectivity receiving data stream group X ₂..., STA 232n adopts matched filter matrix W _kselectivity receiving data stream group X _k.

Various embodiments of the present invention comprise for calculating beamforming matrix F ₁, F ₂..., F _kwith matched filter matrix W ₁, W ₂..., W _kiterative program, to maximize by channel estimate matrix H ₁, H ₂..., H _kthe total capacity of the communication channel characterizing.

In one embodiment of the present of invention, each STA receives L spatial flow and adopts a plurality of M reception antennas, but various embodiments of the present invention are not limited.Various embodiments of the present invention also can be carried out while selecting the quantity of spatial flow quantity in each spatial flow (spatial stream) group and each STA place reception antenna independent.

The communication system of setting forth in Fig. 2 can be represented by formula shown below:

$\left(\begin{array}{c}{R}_1\\ .\\ .\\ .\\ R_K\end{array}\right)=\left(\begin{array}{c}{H}_1\\ .\\ .\\ .\\ H_K\end{array}\right)\left(\begin{array}{ccc}{F}_1& ...& F_K\end{array}\right)\left(\begin{array}{c}{X}_1\\ .\\ .\\ .\\ X_K\end{array}\right)+\left(\begin{array}{c}{n}_1\\ .\\ .\\ .\\ n_K\end{array}\right)---\left[1\right]$

R wherein ₁r _kthe received signal vector that represents the signal that each corresponding STA place receives, H ₁h _krepresent the channel estimate matrix associated with communication channel from AP 202 to each corresponding STA, F ₁f _krepresent be positioned at the AP 202 corresponding wave beams formation in place piece 212a, 212b ..., the beam forming matrix of 212n association, X ₁x _kthe data vector of each of a plurality of spatial flow groups that expression AP 202 places generate, and n ₁n _kthe noise vector that represents the interchannel noise associated with communication medium 252.

Reference formula [1], and comprise N transmitting antenna and generate a plurality of K data vectors at AP 202, each data is relevant all to be comprised in example embodiment of the present invention of L data flow, in demonstration MU-MIMO communication system, comprise a plurality of K STA, each adopts a plurality of M antennas, each received signal vector R _icomprise M capable and 1 row, each channel estimate matrix H _icomprise the capable and N of M row, each beam forming matrix F _icomprise the capable and L of N row, each data vector X _icomprise capable and 1 row of L, and each noise vector n _icomprise M capable and 1 row.Reference formula [2], each off diagonal element (H _if _j, i ≠ j) and corresponding to the interference signal at each STA place.For example, for STA 232a, received signal vector R ₁can represent by formula shown below:

R ₁＝H ₁F ₁X ₁+H ₁F ₂X ₂+…+H ₁F _KX _K [3]

In formula [3], the signal component of being launched by AP 202 that STA 232a receives is expressed as H ₁f ₁x ₁, residual signal component H in formula [3] ₁f _jx _j(wherein j ≠ 1) represents the interference signal that STA 232a receives.That the interference signal corresponding A P 202 representing in formula [3] launches for other STA receives but the signal that received by STA232a.

Each STA adopts matched filter to filter the interference signal as shown in formula [3].In an example embodiment of the present invention, each STA adopts corresponding matched filter, the matched filter matrix W of this matched filter correspondence in formula below _irepresent:

Reference formula [4], and adopt a plurality of M antennas and receive in example embodiment of the present invention of a plurality of L data flow each matched filter matrix W in each of a plurality of K STA _icomprise the capable and M of L row.Accordingly, each trap signal vector W _ir _icomprise L capable and 1 row.Each off-diagonal matrix element (W _ih _if _j, i ≠ j) and the filtration interference signal at corresponding STA place.For example, for STA 232a, trap signal vector W _ir _iby formula shown in below, represented:

W ₁R ₁＝W ₁H ₁F ₁X ₁+W ₁H ₁F ₂X ₂+…+W ₁H ₁F _KX _K [5]

In formula [5], desired signal component is by W ₁h ₁f ₁x ₁item represents, residual signal component W in formula [5] ₁h ₁f _jx _j(wherein j ≠ 1) represents interference signal.By channel estimate matrix H ₁the capacity C of the communication channel characterizing ₁, in matched filtering matrix W ₁while successfully restraining the interference signal component in formula [3], reach maximum.Reference formula [5], this condition occurs in:

W ₁H ₁F ₂X ₂+…+W ₁H ₁F _KX _K＝0 [6]

Various embodiments of the present invention comprise for calculating beamforming matrix F ₁... F _kwith matched filter matrix W ₁... W _kiterative program, make channel C _i(i=1,2 ..., K) total capacity C _mU-MIMOreach maximum.Total capacity C _mU-MIMOby formula shown below, represented:

$C_{\mathrm{MU}-\mathrm{MIMO}}=\underset{i=1}{\overset{K}{\mathrm{\Σ}}}{C}_i---\left[7\right]$

C wherein _iexpression is by channel estimate matrix H ₁the channel capacity characterizing.Each capability value C _ican be represented by formula shown below:

$C_i={\log }_2\left(\det \right[I+F_i^H{H}_i^H{(H_i\left(\underset{k\≠i}{\mathrm{\Σ}}{F}_k{F}_k^H\right)H_i^H+I{\mathrm{\σ}}^2)}^{-1}{H}_i{F}_i\left]\right)---\left[8\right]$

Wherein i represent corresponding a plurality of K STA 232a, 232b ..., the user index of in 232n, matrix A ^hthe complex conjugate of representing matrix A (or close transposition in distress) matrix, A ^-1the inverse matrix of representing matrix A, matrix I representation unit matrix and σ ²the noise power that represents each reception antenna place.In an example embodiment of the present invention, corresponding additive white Gaussian noise (Additive White Gaussion Noise, the AWGN) channel of noise power.

Reference formula [8], in various embodiments of the present invention, can be at the corresponding capability value C not changing as shown in formula [8] _isituation under, in conjunction with corresponding beam forming matrix F _iadopt precoding unitary matrice P _i(for example,, by by matrix product F _ip _ireplace matrix F _i).In an example embodiment of the present invention, spatial flow vector X _ican be along with inputing to beam forming matrix F _ipre-coding matrix P _ioutput and input to pre-coding matrix P _i.In an example embodiment of the present invention, pre-coding matrix P _icomprise L _irow and L _irow (L wherein _icorresponding to MU-MIMO communication system in the quantity of data flow of i user-association).

In various embodiments of the present invention, the capacity of SU-MIMO channel that can be based on shown in following formula is determined capability value C _mU-MIMOcoboundary:

$C_{\mathrm{MU}-\mathrm{MIMO}}\≤{\log }_2\left(\det \right[I+\frac{1}{{\mathrm{\σ}}^2}{H}^{H}H\left]\right)---\left[9\right]$

Wherein H represents the channel estimate matrix of SU-MIMO channel.

Reference formula [8], wherein one:

$(H_i\left(\underset{k\≠i}{\mathrm{\Σ}}{F}_k{F}_k^H\right)H_i^H+I{\mathrm{\σ}}^2)---\left[10\right]$

Comprise distracter

with noise item I σ ².So interference plus noise item in formula [10] representation formula [8].

Based on formula [7] and [8], total capacity C _mU-MIMOcan be represented by formula shown below:

$C_{\mathrm{MU}-\mathrm{MIMO}}=\underset{i=1}{\overset{K}{\mathrm{\Σ}}}{\log }_2\left(\det \right[I+F_i^H{H}_i^H{(H_i\left(\underset{k\≠i}{\mathrm{\Σ}}{F}_k{F}_k^H\right)H_i^H+I{\mathrm{\σ}}^2)}^{-1}{H}_i{F}_i\left]\right)---\left[11\right]$

In various embodiments of the present invention, and under high SNR condition:

$F_i^H{H}_i^H{H}_i{F}_j=0,(j\≠i)---\left[12\right]$

Capability value can be at beam forming matrix F _iduring for quadrature, reach maximum, as following formula represents:

$F_i^H{F}_i=D_i---\left[13\right]$

Matrix D wherein _irepresent orthogonal matrix.

In various embodiments of the present invention, can be for example based on leakage signal noise ratio (Signal-to-Leakage-plus-Noise Ratio, SLNR) beam forming matrix or based on balanced (equalized) alone family (SU) Beamforming Method calculating beamforming matrix F _i.For balanced SU Beamforming Method, for example, can be by following calculating beamforming matrix F:

F＝V(V ^HV) ^-1 [14a]

Wherein F comprises a plurality of beam forming matrix F corresponding to a plurality of K users in MU-MIMO system _i:

F＝[F ₁ F ₂ … F _K] [14b]

And V comprises the H corresponding with a plurality of K users in MU-MIMO system _ia plurality of characteristic vector V _i:

V＝[V ₁ V ₂ … V _K] [14c]

Conventionally, each beam forming matrix F _ican not quadrature.

In various embodiments of the present invention, can be according to following calculating intermediary matrix:

$Y_i^H{Y}_i=F_i^H{F}_i---\left[15a\right]$

Wherein can adopt Cholesky decomposition method to calculate intermediary matrix Y _i.Intermediary matrix Y that can be based on calculating _icompute matrix Z _i:

$Z_i=Y_i^{-1}---\left[15b\right]$

Based on matrix Z _iwith the beam forming matrix F calculating _i, can calculate orthogonal beams by formula shown below and form matrix

${\tilde{F}}_i=F_i{Z}_i---\left[16\right]$

Fig. 3 is the flow chart of the example steps that forms for MU-MIMO system orthogonal beams according to the elaboration of one embodiment of the invention.With reference to figure 3, label 300 has been set forth when adopting maximum SLNR Beamforming Method calculating beamforming matrix F _itime the orthogonal beams example steps that forms, and label 350 has been set forth when adopting balanced SU Beamforming Method calculating beamforming matrix F _itime the orthogonal beams example steps that forms.

Reference number 300, given noise variance parameter σ and a plurality of channels associated matrix R ₁, R ₂..., R _k, wherein:

$R_i=H_i^H{H}_i---\left[17\right]$

H wherein _ithe channel estimate matrix that represents i user in MU-MIMO system.Maximum SLNR wave beam forms piece can form to calculate corresponding a plurality of beam forming matrix F with maximum SLNR wave beam _i.Conventionally, the beam forming matrix F of each calculating _inot quadrature, as shown in following formula:

$F_i^H{F}_i\≠D_i---\left[18\right]$

Matrix D wherein _irepresent orthogonal matrix.

In various embodiments of the present invention, for the beam forming matrix F of each calculating _i, can form matrix by calculating corresponding orthogonal beams shown in formula [13]-[16]

.Reference number 300, can pass through each quadrature piece 304a, 304b ..., 304n representation formula [13]-[16].

Reference number 350, shows a plurality of eigenvectors matrix V ₁, V ₂..., V _k, each matrix V wherein _icomprise N capable (for example, N represents the quantity of AP202 place transmitting antenna in MU-MIMO communication system) and L _irow, can be based on respective channels estimated matrix H _isingular value decomposition method (SVD) calculate described matrix V _i(for example, each matrix V _ican comprise L in singular value decomposition method _ithe right singular vector that maximum singular value is corresponding).Given selectable noise variance parameter σ and a plurality of matrix V ₁, V ₂..., V _k, balanced SU wave beam forms piece 352 can form to calculate corresponding a plurality of beam forming matrix F with balanced wave beam _i.Conventionally, the beam forming matrix F of each calculating _inot quadrature, as represented in formula [18].In various embodiments of the present invention, for the beam forming matrix F of each calculating _i, can form matrix by calculating corresponding orthogonal beams shown in formula [13]-[16]

reference number 350, can pass through each quadrature piece 354a, 354b ..., 354n representation formula [13]-[16].

In various embodiments of the present invention, can adopt corresponding precoding unitary matrice (unitary precoding matrix) P _ithe data flow of each i user-association is carried out to precoding.The data flow of precoding inputs to corresponding orthogonal beams and forms matrix

wave beam form piece.In an example embodiment of the present invention, when AP 202 places adopt precoding in the demonstration MU-MIMO communication system representing, based on orthogonal beams, form matrix shown in can be as follows in Fig. 2

with corresponding pre-coding matrix P _ithe orthogonal beams that calculating has precoding forms matrix

${\widetilde{\stackrel{~}{F}}}_i={\tilde{F}}_i{P}_i---\left[19\right]$

Fig. 4 is the flow chart in the elaboration MU-MIMO communication system according to one embodiment of the invention with the example steps that the orthogonal beams of precoding forms.With reference to figure 4, label 400 has been set forth when adopting maximum SLNR Beamforming Method calculating beamforming matrix F _itime the orthogonal beams example steps that forms, and label 450 has been set forth when adopting balanced SU Beamforming Method calculating beamforming matrix F _itime there is the example steps that the orthogonal beams of precoding forms.

Reference number 400, given noise variance parameter σ and a plurality of matrix R ₁, R ₂..., R _k, can use maximum SLNR wave beam to form and calculate corresponding a plurality of beam forming matrix F _i.Conventionally, the beam forming matrix F of each calculating _iit not quadrature.In various embodiments of the present invention, for the beam forming matrix F of each calculating _i, can form matrix by calculating corresponding orthogonal beams shown in formula [13]-[16]

reference number 400, can pass through each quadrature piece 404a, 404b ..., 404n representation formula [13]-[16].

Orthogonal beams for each calculating forms matrix

can form matrix by calculating the corresponding orthogonal beams with precoding shown in formula [19]

reference number 400, can by each SU wave beam form piece 406a, 406b ..., 406n representation formula [19].

Reference number 450, given selectable noise variance parameter σ and a plurality of matrix V ₁, V ₂..., V _k, can use balanced SU wave beam to form and calculate corresponding a plurality of beam forming matrix F _i.Conventionally, the beam forming matrix F of each calculating _iit not quadrature.In various embodiments of the present invention, for the beam forming matrix F of each calculating _i, can form matrix by calculating corresponding orthogonal beams shown in formula [13]-[16]

reference number 450, can pass through each quadrature piece 454a, 454b ..., 454n representation formula [13]-[16].Orthogonal beams for each calculating forms matrix

can form matrix by calculating the corresponding orthogonal beams with precoding shown in formula [19]

reference number 450, can by each SU wave beam form piece 456a, 456b ..., 456n representation formula [19].

In various embodiments of the present invention, for the receiver of i user in MU-MIMO system, can adopt SVD (as shown in following formula) to calculate pre-coding matrix P _i, wherein this receiver for example STA 232a section adopt linear equalizing method:

$U_i{S}_i{V}_i^H=H_i{\tilde{F}}_i---\left[20\right]$

S wherein _irepresent diagonal angle singular value matrix, U _irepresent left singular value vector matrix, V _irepresent right singular value vector matrix.In each embodiment of this aspect, matrix U _iand V _ifor unitary matrice.Based on formula [20], calculate pre-coding matrix F shown in can be as follows _i:

$P_i=V_i\left[\begin{array}{c}{I}_{L_i}\\ 0\end{array}\right]---\left[21\right]$

I wherein _lirepresentation unit matrix, comprises the capable and Li of Li row.

In various embodiments of the present invention, for the receiver of i user in MU-MIMO system, can calculate each pre-coding matrix P _ithe rear likelihood (ML) of optimizing receiver detects performance, wherein this receiver for example STA232a adopt likelihood detection.For the demonstration methods that promotes ML receiver performance, at application number, be No.12/246,206, the applying date is open in the United States Patent (USP) on October 6th, 2008, its by reference integral body be incorporated herein.

An alternative embodiment of the invention provides a kind of computer-readable medium, on it, the computer program of storage has the code segment that at least one can be carried out by computer, makes computer can carry out the step forming for multi-user's multiple-input and multiple-output (MU-MIMO) system orthogonal beams described herein.

Accordingly, available hardware of the present invention, software or combination wherein realize.The present invention can realize in integrated mode at least one computer system, or different unit is placed in to a plurality of mutually connected computer systems in discrete mode, realizes.Be suitable for carrying out any computer system of method described in the invention or other device is all suitable for.Typical hardware and software be combined as the general-purpose computing system with computer program, when this program is loaded and carries out, control computer system, make it carry out method described in the invention.

The present invention can also implement by computer program, and described program package, containing whole features that can realize the inventive method, when it is installed in computer system, by operation, can be realized method of the present invention.Computer program in present specification refers to: any expression formula that can adopt one group of instruction that any program language, code or symbol write, this instruction group makes system have information processing capability, directly to realize specific function, or after carrying out following one or two step, a) convert other Languages, code or symbol to; B) with different forms, reproduce, realize specific function.

The present invention is described by specific embodiment, and those skilled in the art know, without departing from the spirit and scope of the present invention, can carry out various changes or be equal to replacement these features and embodiment.In addition, under instruction of the present invention, can modify to adapt to concrete situation and material and can not depart from the spirit and scope of the present invention these features and embodiment.Therefore, the present invention is not subject to the restriction of specific embodiment disclosed herein, and the embodiment within the scope of all the application's of falling into claim belongs to protection scope of the present invention.

quoting of related application

The application advocates that the applying date is that January 20, application number in 2010 are NO.61/296, the priority of 633 U.S. Provisional Application.

Claims (10)

1. a method for processing signals, is characterized in that, comprising:

By one or more processors and/or circuit, carry out:

Based on a plurality of channel estimate matrixs, channels associated matrix and/or eigenvectors matrix, calculate a plurality of beam forming matrixs in multiuser mimo system;

Based on described a plurality of beam forming matrixs, calculate a plurality of orthogonal matrixes;

Based on described a plurality of beam forming matrixs and described a plurality of orthogonal matrix, determine that a plurality of orthogonal beams form matrix;

For each definite orthogonal beams, forming matrix, is corresponding subscriber devices compute unique user channel capacity value; And

Calculate a plurality of calculated unique user channel capacity value sums as overall channel capacity;

Wherein, based on calculating described a plurality of orthogonal matrixes and determining that described a plurality of orthogonal beams forms matrix, described overall channel capacity is maximized.

2. the method for processing signals according to claim 1, is characterized in that, comprises based on described a plurality of beam forming matrixs and generates a plurality of intermediary matrixs.

3. the method for processing signals according to claim 2, is characterized in that, comprises and selects one of described a plurality of intermediary matrixs and described a plurality of beam forming matrixs corresponding selected one.

4. the method for processing signals according to claim 3, it is characterized in that, the matrix product of the close transformation matrix of strategic point of described selected of described selected and described a plurality of intermediary matrixs of wherein said a plurality of intermediary matrixs equals the matrix product of the close transformation matrix of strategic point of selected of described correspondence of selected and described a plurality of beam forming matrixs of the described correspondence of described a plurality of beam forming matrixs.

5. the method for processing signals according to claim 4, is characterized in that, comprises described selected based on the described a plurality of intermediary matrixs of Cholesky decomposition method generation.

6. the method for processing signals according to claim 5, is characterized in that, one in described a plurality of orthogonal matrixes equates with the inverse matrix of described selected of described a plurality of intermediary matrixs.

7. the method for processing signals according to claim 6, it is characterized in that, selected one of described correspondence who comprises described selected one and described a plurality of beam forming matrixs based on described a plurality of orthogonal matrixes, calculates described a plurality of orthogonal beams and forms of matrixes.

8. the method for processing signals according to claim 1, is characterized in that, comprises a plurality of pre-coding matrixes that calculate for described multiuser mimo system.

9. the method for processing signals according to claim 8, is characterized in that, each of described a plurality of pre-coding matrixes is corresponding at least one of a plurality of users in described multiuser mimo system.

10. a system for processing signals, is characterized in that, comprising:

The first circuit module, calculates a plurality of beam forming matrixs in multiuser mimo system based on a plurality of channel estimate matrixs, channels associated matrix and/or eigenvectors matrix;

Second circuit module, calculates a plurality of orthogonal matrixes based on described a plurality of beam forming matrixs;

Based on described a plurality of beam forming matrixs and described a plurality of orthogonal matrix, determine that a plurality of orthogonal beams form matrix;

Tertiary circuit module, forms matrix for each definite orthogonal beams, is corresponding subscriber devices compute unique user channel capacity value; And

The 4th circuit module, calculates a plurality of calculated unique user channel capacity value sums as overall channel capacity;

Wherein, based on calculating described a plurality of orthogonal matrixes and determining that described a plurality of orthogonal beams forms matrix, described overall channel capacity is maximized.

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