CN101262456A - Method and system for processing communication signal - Google Patents

Abstract

The invention discloses a method and a system for processing communication signal. Aspects of a method and system for a delta quantizer for rate reduction pre-coding matrices may include quantizing a change in channel state information in a MIMO pre-coding system onto a codebook and generating a pre-coding matrix based on at least the channel state information. The channel state information may be a matrix V and one or more associated singular values. The matrix V may be generated using Singular Value Decomposition (SVD) or Geometric Mean Decomposition (GMD). One or more columns of the matrix V may be selected based on the one or more associated singular values and may be combined to enable the generation of the pre-coding matrix. The codebook may comprise one or more unitary matrices. An index of an element of the codebook, onto which the change in channel state information is quantized, may be transmitted from a receiver to a transmitter.

Description

The method and system that is used for process communication signals

Technical field

The present invention relates to the signal processing of communication system.More particularly, the present invention relates to a kind of method and system that is used for speed compression pre-coding matrix.

Background technology

Mobile communication has changed people's communication mode, and mobile phone has also become essential part people's daily life from luxury goods.Today, the use of mobile device is arranged by social environment, and is not subjected to region and technology limitation.Though voice communication can be satisfied the basic demand that people exchange, and moving speech communication also further infiltrated daily life, and the next stage of mobile communication development is a mobile Internet.Mobile Internet will become the common source of daily information, naturally should realize the movable type visit to the simple general-purpose of these data.

(Third Generation, 3G) the cellular network specialized designs satisfies these following demands of mobile Internet to the third generation.Along with a large amount of appearance and the use of these services, for cellular network operator, (Quality of Service, factors such as cost efficiency optimization QoS) will become more even more important than now for network capacity and service quality.Can realize these factors by the meticulous network planning and operation, the improvement of transmission method and the raising of receiver technology.Therefore, operator needs new technology, so that increase downlink throughput capacity, thereby provides than those cable modems and/or better QoS capacity of DSL service provider and speed.

In order to satisfy described demand,, in reflector and receiver, all use the communication system of a plurality of antennas to have received increasing attention recently because promise increases capacity significantly in wireless decline environment.These many antenna configurations are also referred to as and are intelligent antenna technology, the negative effect of multipath and/or signal interference when can be used for alleviating signal and receiving.Insight for satisfying the cumulative capacity requirement of said system, will be used intelligent antenna technology more and more in advance, simultaneously configurating base station facility and moving user unit in cellular system.Can provide the radio multimedium service of voice, video and data communication from the current voice-based next generation of service, these demands are all displaying gradually.

The use of pilosity and/or multiple receive antenna is designed to obtain diversity gain, and increases the degree of freedom, to be suppressed at the interference that produces in the signal receiving course.Diversity gain improves systematic function by increasing received signal to noise ratio and stable transfer.On the other hand, the more freedom degree allows the transmission of a plurality of whiles by firmer anti-signal interference being provided and/or allowing higher capacity to reuse with higher frequency.For example, in the communication system of integrated multiple antenna receiver, M reception antenna can be used for making (M-1) individual interference effect invalid.Correspondingly, can utilize N transmitting antenna in same band, to send N signal simultaneously,, send signal and then can be broken down into N independent signal by N the antenna collection that uses in the receiver.Use the system of a plurality of transmissions and reception antenna to can be described as multiple-input, multiple-output (MIMO) system.A very attractive aspect of multiaerial system, especially mimo system is, uses these transmission configuration can increase power system capacity greatly.For fixing total transmission of power, the capacity that the MIMO configuration provides and the signal to noise ratio (snr) of increase are proportional.For example, in multidiameter fading channel, the every increase of SNR 3-dB, the MIMO configuration can increase the general M power system capacity in additional bit/cycle.

Yet, in radio communication, especially in the wireless handheld machine equipment,, limited the broad development of multiaerial system because the cost that the increase of size, complexity and power consumption causes increases.This causes the problem of wireless system design and application.Therefore, some initialization of multiaerial system can concentrate in the system that supports single user's point-to-point link.Other work work may be paid close attention to multi-user's scene.Use the communication system of many antennas can largely improve the capacity of system.

Use the MIMO technology in order to obtain extraordinary performance gain, however need provide channel information to transmitter allowing, for example, the MIMO precoding.Can acquire benefit or needs understanding channel just so-called channel condition information (CSI) in the MIMO of MIMO transmitter precoding and other MIMO technology.In addition, because most wireless system is operated in Frequency Division Duplexing (FDD) (FDD) pattern, uplink and downlink connect uses different frequencies.In these cases, can only obtain the channel measured value of transmitter terminal by returning in the receiver measured channel and with feedback information.Yet along with the increase that transmits and receives antenna amount in the mimo system, feeding back channel state information may comprise the transmission lot of data.In addition, may need restricting data speed painstakingly in some cases, to improve the transmitting boundary of communication system.

Compare the follow-up system that will introduce in conjunction with the accompanying drawings of the present invention, other limitation of prior art and drawback are conspicuous for the person of ordinary skill of the art.

Summary of the invention

The method and/or the system that are used for speed compression pre-coding matrix show fully and/or describe more complete in the claims description in conjunction with at least one accompanying drawing.

According to an aspect of the present invention, a kind of method that is used for process communication signals comprises:

Code book is quantized in the variation of channel condition information in the MIMO pre-coding system; And

At least produce pre-coding matrix based on described channel condition information.

As preferably, described channel condition information is the relevant singular value with one or more of matrix V.

As preferably, described method further comprises uses singular value decomposition (SVD) to produce described matrix V.

As preferably, described method comprises that further using geometric mean to decompose (GMD) decomposes and produce described matrix V.

As preferably, described method further comprises row or a multiple row of selecting described matrix V based on described one or more relevant singular value.

As preferably, described method further comprises and merges described row of having selected or multiple row to produce described pre-coding matrix.

As preferably, described code book comprises one or more unitary matrice.

As preferably, described method further is included in the described MIMO pre-coding system transmitter that indexes by the corresponding element of receiver emission code book, and wherein channel condition information changes and quantizes to described code book.

As preferably, a kind of communication system that comprises described MIMO pre-coding system comprises one or more transmitting antennas and one or more reception antenna.

As preferably, described method further comprises uses described pre-coding matrix, the matrix of the described MIMO pre-coding system of linear transformation transmitter.

According to an aspect of the present invention, a kind of system that is used for process communication signals comprises:

One or more circuit in the MIMO pre-coding system, described one or more circuit is used for:

Code book is quantized in the variation of channel condition information; And

At least produce pre-coding matrix based on described channel condition information.

As preferably, described channel condition information is the relevant singular value with one or more of matrix V.

As preferably, described one or more circuit uses singular value decomposition (SVD) to produce described matrix V.

As preferably, described one or more circuit uses geometric mean to decompose (GMD) and produces described matrix V.

As preferably, described one or more circuit is selected row or a multiple row of described matrix V based on described one or more relevant singular value.

As preferably, described one or more circuit merges described row of having selected or multiple row to produce described pre-coding matrix.

As preferably, described code book comprises one or more unitary matrice.

As preferably, by the transmitter that indexes of the corresponding element of receiver emission code book, wherein channel condition information changes and quantizes to described code book described one or more circuit in described MIMO pre-coding system.

As preferably, comprise the communication system of described MIMO pre-coding system, comprise one or more transmitting antennas and one or more reception antenna.

As preferably, described one or more circuit uses described pre-coding matrix, the matrix of the described MIMO pre-coding system of linear transformation transmitter.

These and other advantage of the present invention, aspect and new features, with and specific embodiment, can from following description and figure, obtain understanding more completely.

Description of drawings

Figure 1A is the schematic diagram in conjunction with the honeycomb multipath communication of the embodiment of the invention between base station and mobile computing terminal.

Figure 1B is the schematic diagram according to the MIMO communication system of the embodiment of the invention.

Fig. 2 is the block diagram according to the MIMO precoding transceiver chain model of the embodiment of the invention.

Fig. 3 is the block diagram according to the MIMO pre-coding system of the limited ratio channel condition information feedback of having of the embodiment of the invention.

Fig. 4 is the flow chart according to the MIMO precoding processing of the embodiment of the invention.

Embodiment

Embodiments of the invention relate to the method and system that is used for speed compression pre-coding matrix.Described some aspects that are used for the method and system of speed compression pre-coding matrix comprise: code book is quantized in the variation of the channel condition information of MIMO pre-coding system, and produced pre-coding matrix based on described channel condition information at least.Described channel condition information can be the relevant singular value with one or more of matrix V.Described matrix V can be used singular value decomposition (SVD) or geometric mean to decompose (GMD) and produce.Can be based on row or the multiple row of described one or more relevant singular value selection matrix V, the row of described selection can merge to produce pre-coding matrix.Described code book comprises one or more unitary matrice.By the transmitter that indexes of the corresponding element of receiver emission code book, wherein channel condition information changes and quantizes to described code book in this MIMO pre-coding system.The communication system that comprises described MIMO pre-coding system comprises one or more transmitting antenna and one or more reception antenna.Use described pre-coding matrix, the matrix of the described MIMO pre-coding system of linear transformation transmitter.

Figure 1A shows in conjunction with the honeycomb multipath communication of the embodiment of the invention between base station and mobile computing terminal.With reference to Figure 1A, house 120, portable terminal 122, factory 124, base station 126, automobile 128 and communication path 130,132 and 134 have been provided.

Base station 126 and portable terminal 122 include suitable logic, circuit and/or code, are used for producing and handling the MIMO signal of communication.Radio communication between base station 126 and portable terminal 122 can be undertaken by wireless channel.Described wireless channel comprises a plurality of communication paths, for example, and communication path 130,132 and 134.Described wireless channel can move and dynamic change along with portable terminal 122 and/or automobile 128.In some cases, portable terminal 122 be positioned at base station 126 sighting distance (LOS, line-of-sight).In other cases, may not direct sighting distance between portable terminal 122 and the base station 126, radiofrequency signal is propagated between the reflection communication path between the communication entity, representative communication path 130,132 and 134 as shown in the figure.Described radiofrequency signal can be reflected by the obstacle such as the mountain of man-made structures such as house 120, factory 124 or automobile 128 or existence naturally.Such system refers to non line of sight (NLOS) communication system.

Communication system may comprise LOS and NLOS signal component simultaneously.If there is the LOS signal component, described LOS signal component is than strong many of NLOS signal component.In some communication systems, the NLOS signal component can produce to be disturbed and the reduction receiver performance.This refers to multipath and disturbs.For example, communication path 130,132 and 134 reaches portable terminal 122 and has different delays.Communication path 130,132 and 134 can also have different decay.For example, in down link, the signal that receives at portable terminal 122 can be a differential declines communication path 130,132, and/or the summation of 134 signal, and these different communication paths may be nonsynchronous and dynamic changes.Such channel is called weak multipath channel.Weak multipath channel can be introduced interference, but also can introduce the diversity and the degree of freedom for described wireless channel.In the base station and/or portable terminal have the communication system of many antennas, mimo system for example, be particularly suitable for utilizing the characteristic of wireless channel and can obtaining very big performance gain by weak multipath channel, with respect in the base station 126 and portable terminal 122 have the communication system (particularly NLOS communication system) of single antenna, the communication system of described many antennas can obtain very big performance and improve.

Figure 1B shows the schematic diagram according to the MIMO communication system of the embodiment of the invention.With reference to Figure 1B, show MIMO transmitter 102 and MIMO receiver 104, and antenna 106,108,110,112,114,116.Also show wireless channel among the figure, described channel comprises communication path h ₁₁, h ₁₂, h ₂₂, h ₂₁, h _{2 NTX}, h _{1 NTX}, h _NRX1, h _NRX2, h _{NRX NTX}, h wherein _MnCan represent channel coefficients from transmitter antenna n to receiver antenna m.Has N _TXIndividual transmitter antenna and N _RXIndividual receiver antenna.Give emission symbol x among the figure ₁, x ₂, x _NTXWith receiving symbol y1, y2, y _NRX

MIMO transmitter 102 includes suitable logic, and circuit and/or code are used for producing emission symbol x _iI ∈ 1,2 ... N _TX, described symbol is by 106,108,110 emissions of the transmitting antenna shown in Figure 1B.MIMO receiver 104 includes suitable logic, and circuit and/or code are used to handle the receiving symbol y that receives by the reception antenna shown in Figure 1B 112,114,116 _iI ∈ 1,2 ... N _RX.Shown in input/output relation between that launch in mimo system and the signal that receives can be expressed as:

y＝Hx+n

Y=[y wherein ₁, y ₂... y _NRX] ^TBe to have N _RXThe column vector of individual element,

Expression vector transposition, H=[h _Ij]: i ∈ 1,2 ... N _RX; J ∈ 1,2 ... N _TXExpression N _RX* N _TXThe channel matrix of dimension, x=[x ₁, x ₂... x _NTX] ^TBe to have N _TXThe column vector of individual element, n are to have N _RXThe noise samples column vector of individual element.Channel matrix H can be write as H=U ∑ V under the situation of using singular value decomposition (SVD) ^H, wherein

Expression Hamilton's transposition (hermitian transpose), U is N _RX* N _TXUnitary matrice, ∑ is N _TX* N _TXDiagonal matrix, and V is N _TX* N _TXUnitary matrice.Also can use other matrix decomposition of diagonalization or the described matrix H of conversion, rather than SVD decomposes.If the receiver algorithms of carrying out in the MIMO receiver 104 are the continuous Interference Cancellations (OSIC) that for example sort, then can transition matrix H to time/other matrix decomposition of upper triangular matrix also is fine.Such decomposition comprises that geometric mean decomposes (GMD), wherein H=QRP ^H, wherein R can be that the geometric mean of the singular value of H is positioned at the upper triangular matrix on the diagonal element, Q and P can be unitary matrice.

Fig. 2 shows the block diagram according to the MIMO precoding transceiver chain model of the embodiment of the invention.With reference to figure 2, show MIMO pre-coding system 200, comprise MIMO transmitter 202, MIMO baseband equivalence channel 203, MIMO receiver 204 and addition module 208.MIMO transmitter 202 comprises transmitter (TX) baseband processing module 210 and emission precoding module 214.MIMO baseband equivalence channel 203 comprises wireless channel 206, TX radio frequency (RF) processing module 212 and receiver (RX) RF processing module 218.MIMO receiver 204 comprises precoding decoder module 216 and RX baseband processing module 220.Also show symbolic vector s, precoding vectors x, noise vector n among the figure, receive vector y and channel-decoding vector y '.

MIMO transmitter 202 comprises baseband processing module 210, and it includes suitable logic, circuit and/or code, is used to produce the MIMO base band transmit.Described MIMO base band transmit can be transferred to emission precoding module 214.Through suitably encoding with emission in wireless channel 206, emission precoding module 214 includes suitable logic, circuit and/or code to be used to making it carry out these functions to baseband signal in emission precoding module 214.TX RF processing module 212 includes suitable logic, and circuit and/or code are used for making the signal that is transferred to TX RF processing module 212 to be modulated onto radio frequency (RF) to launch at wireless channel 206.RX RF processing module 218 includes suitable logic, and circuit and/or code are used to carry out the radio-frequency front-end function, to be received in the signal of emission in the wireless channel 206.RX RF processing module 218 includes suitable logic, and circuit and/or code are used for its input signal is demodulated to baseband signal.Addition module 208 is illustrated in the MIMO receiver noise is added in the signal that receives.MIMO receiver 204 comprises precoding decoder module 216, and the signal that its linear codec receives also transmits described signal to RX baseband processing module 220.RX baseband processing module 220 includes suitable logic, and circuit and/or code are used for this baseband signal is used further signal processing.

MIMO transmitter 202 comprises baseband processing module 210, and it includes suitable logic, and circuit and/or code are used to produce the MIMO base band transmit.Described MIMO base band transmit is transferred to emission precoding module 214, can is-symbol vector s.Symbolic vector s can be N _TXThe vector of * 1 dimension.

The 214 couples of symbolic vector s of emission precoding module carry out linear transformation, make x=Ws, and wherein the dimension of W is N _TXMultiply by the length of s, and x=[x ₁, x ₂... x _NTX] ^TEach element of precoding vectors x is at N _TXLaunch on the different antennae in the available antenna.

The precoding vectors x of emission is by MIMO baseband equivalence channel 203.By N _RXThe signal y that individual receiver antenna receives transmits x by MIMO baseband equivalence channel 203 conversion (being represented by matrix H), and adds that noise component(s) (being expressed as noise vector n) obtains.Shown in addition module 208, receive vector y and be expressed as y=Hx+n=HWs+n.Receive vector y and be transferred to precoding decoder module 216, wherein can carry out linear codec operation B to obtain decoded vector y '=B receiving vector y ^HY=B ^HHWs+B ^HN, wherein B is the complex matrix of suitable dimension.Decoded vector y ' then is transferred to RX baseband processing module 220, carries out further signal processing in this output to precoding decoder module 216.

If it is all known at MIMO transmitter 202 and MIMO receiver 204 ends to be applied to launch the transfer function H of MIMO baseband equivalence channel 203 of precoding vectors x, then described channel can for example, be provided with W=V and B=U, wherein H=U ∑ V by diagonalization ^HIt is singular value decomposition.In these cases, channel-decoding vector y ' is shown in the following relational expression:

y’＝U ^HU∑V ^HVs+U ^Hn＝∑s+U ^Hn

Because ∑ is a diagonal matrix, do not disturb between the element of the symbolic vector s among the y ' to exist, therefore described wireless communication system looks like and has up to N _TXThe wireless communication system of individual parallel single antenna is such, and for each element of s, the order of channel matrix H can be smaller or equal to N _TX

Fig. 3 shows the block diagram according to the MIMO pre-coding system of the limited ratio channel condition information feedback of having of the embodiment of the invention.With reference to figure 3, the MIMO pre-coding system 300 that illustrates comprises part MIMO transmitter 302, part MIMO receiver 304, wireless channel 306, addition module 308 and feedback channel 320.Part MIMO transmitter 302 comprises emission precoding module 314.Part MIMO receiver 304 comprises precoding decoder module 316, channel estimation module 322, channel quantitative module 310, channel decomposing module 312 and code book processing module 318.Fig. 3 also shows symbolic vector s, precoding vectors x, noise vector n, receives vector y and decoded vector y '.

Emission precoding module 314, wireless channel 306, addition module 308 and precoding decoder module 316 are basic identical with emission precoding module 214, MIMO baseband equivalence channel 203, addition module 208 and precoding decoder module 216 shown in Fig. 2.Channel estimation module 322 includes suitable logic, and circuit and/or code are used to estimate the transfer function of wireless channel 206.Channel estimation value can send channel decomposing module 312 to, and channel decomposing module 312 includes suitable logic, and circuit and/or code are used to decompose channel.In this respect, the channel that is decomposed is connected to channel quantitative module 310.Channel quantitative module 310 includes suitable logic, and circuit and/or code are used for described channel strip is quantized to code book.Code book processing module 318 includes suitable logic, and circuit and/or code are used to produce code book.Feedback channel 320 is expressed as the channel from part MIMO receiver 304 transmitting channel state informations to part MIMO transmitter 302.

In a lot of wireless systems, channel condition information just about the message of Channel Transmission matrix H, may utilize for transmitter and receiver.Yet,, may wish to know partial channel knowledge at least at transmitter terminal in order to utilize pre-coding system as shown in Figure 2.In the disclosed embodiments of the invention as Fig. 2, MIMO transmitter 302 needs and is used for the unitary matrice V that carries out precoding in the emission precoding module 214 of MIMO transmitter 202.

In frequency division multiplexing (FDD) system, the communication band that is used for the downlink communication from the base station to the portable terminal is different with the frequency band that is used for uplink communication.Because the difference of frequency band, the channel measurement of up link is otiose for down link generally, and vice versa.In these cases, only carry out described measurement, and channel condition information (CSI) can transmit back transmitter by the mode of feedback at receiver end.Reason hereto, CSI can feed back to the emission precoding module 314 of part MIMO transmitter 302 by feedback channel 320 from part MIMO receiver 304.Emission precoding module 314, wireless channel 306 and addition module 308 are basic identical with corresponding module 214,203 and 208 shown in Figure 2.

At part MIMO receiver 304, received signal y can be used for estimating channel transfer function H in channel estimation module 222, use

Expression.For example, diagonal matrix or triangular matrix form can be further resolved in described estimation, and this depends on specific receiver embodiment, explains as Fig. 2.For example, channel decomposing module 312 can be carried out the SVD decomposition: $\hat{H}=\hat{U}\widehat{\mathrm{\Σ}}{\hat{V}}^H.$ Matrix H and

Can be that order satisfies 1≤r≤N _TXMatrix.Under the situation of a plurality of antennas, matrix U, the dimension of ∑ and V increases very soon.In these cases, may wish quantization matrix

Become N _TX* N _RXMatrix V _kAnd the limited unitary matrice collection C of definition before coming from _d={ Q _iSpin matrix Q at the tenth of the twelve Earthly Branches _q ⁰, wherein $V_k=V_{k-1.}{Q}_q^0$ Can be by a last V _k, V just _K-1Produce.Described unitary matrice collection C _dRefer to code book.Matrix

Change speed want slow with respect to the renewal rate of channel.In these cases, emission is to quantization matrix V before _K-1Renewal rather than new matrix V _kBe very economical, and can utilize the channel memory.By from code book C _dIn find and can produce V _kMatrix Q _q ⁰, V wherein _kIn some sense very near matrix

So just enough emission matrix Q _q ⁰Index q to the emission precoding module 314.This can be realized by the feedback channel 320 of channel quantitative module 310.Part MIMO transmitter 302 need be known code book C _dDescribed code book C _dChange slow manyly than channel transfer function H, enough emission precoding module 314, upgrade described code book C by feedback channel 320 periodically from code book processing module 318 _dDescribed code book C _dCan be chosen as static or adaptive.And, described code book C _dCan also concentrate self adaptation or non-self-adapting ground to select from code book, these code book collection comprise the code book of self adaptation and/or Static Design.In these cases, part MIMO receiver 304 can be put at any time and inform that in time employed code book is to part MIMO transmitter 302.Matrix

Can be quantized into V with relational expression as described below _k:

$Q_q^0=\arg \mathrm{ma}{x}_{{\hat{Q}}_q\∈C_d}f\left({\hat{V}}^H{V}_{k-1}{\hat{Q}}_q\right)$

$f\left(A\right)=\left(\frac{1}{N}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\left|a_{\mathrm{jj}}\right|}^2\right)---\left(1\right)$

A=[a wherein _Ij] and the dimension of A all be N * N.Therefore, matrix Q _q ⁰Can be elected to be the Q in the code book _q, it can maximize the function of above definition

Function f (.) is the squared absolute value of input matrix diagonal element on average.By maximization f (.), in some sense, can selection matrix V _k, make product

At utmost similar in appearance to unit matrix.Under some approximate conditions, the expression formula of above f (.) can maximize the momentary output of described precoding MIMO system.In another embodiment of the present invention, described function f (.) can be different with equation (1).Therefore, channel H can estimate in channel estimation module 322, decomposes in channel decomposing module 312.

In channel quantitative module 310, matrix for example

Can be quantized into matrix $V_k=V_{k-1.}{Q}_q^0,$ Index q can feed back to part MIMO transmitter 302 by feedback channel 320.Slow many of the frequency that changes than index q are from the code book C of code book processing module 318 _dCan be transmitted into part MIMO transmitter 302 by feedback channel 320.Described code book C _dCan also be chosen as and to remain unchanged on the time.And, described code book C _dCan also concentrate self adaptation or non-self-adapting ground to select from code book, these code books comprise the code book of self adaptation and/or Static Design.In order to feed back index q, when the radix of code book C | C| is less than or equal to 2 ^M, M bit is just enough.

With reference to as described in Figure 2, MIMO pre-coding system 300 can be launched r≤N _TXParallel data stream.For example, in 4 * 4 mimo systems, can use 4 parallel data streams simultaneously.Yet each data flow needs specific transmitting power, so that the reception of MIMO receiver has enough big signal to noise ratio (snr), thereby satisfies desired performance.In some cases, can use other performance measurement to replace SNR.The transmitting power that obtain needed data transfer rate and/or other performance measurement needs at part MIMO transmitter 302 places increases along with the increase of the distance between part MIMO transmitter 302 and the part MIMO transmitter 304.In some cases, the available launch power at part MIMO transmitter 302 may be limited.In these cases, can have power now to parallel data stream still less by distributing, and increase transmitting boundary.In this, existing power concentration is in data flow still less, and wherein the scope of these data flow can increase.Yet remaining data flow can not used power, because for example, do not have enough transmitting powers, thereby the overall data rate of mimo system 300 has reduced.Therefore, the compromise at data transfer rate and transmitting boundary is possible.

As described in Figure 2, channel matrix can be decomposed, and for example, uses singular value decomposition (SVD): $\hat{H}=\hat{U}\widehat{\mathrm{\Σ}}{\hat{V}}^H.$ Diagonal matrix comprises matrix

Singular value.The capacity of the data flow in the MIMO pre-coding system 300 and SNR and be included in

The absolute value of singular value relevant, just, the active data stream with maximum capacity is those relevant with maximum singular value.With

In each singular value relevant can be

With

Column vector.Write matrix by the form of using column vector

With

Just $\hat{U}=[{\mathrm{<figure-callout\; id="1"\; label="u"\; filenames="A20081007403400181.png,A20081007403400191.png"\; state="\{\{state\}\}">u</figure-callout>}}_1,u_2,...,u_{\mathrm{NTX}}]$ With $\hat{V}=[{\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="A20081007403400181.png,A20081007403400191.png"\; state="\{\{state\}\}">V</figure-callout>}}_1,V_2,...,V_{\mathrm{NTX}}],$ Can use $\hat{H}=\hat{U}\widehat{\mathrm{\&Sigma;}}{\hat{V}}^H=\underset{i=1}{\overset{N_{\mathrm{TX}}}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i{u}_i{v}_i^H,$ Expression singular value decomposition, wherein σ _iBe

In i singular value.In addition, be without loss of generality, can suppose that described singular value arranges according to the order of sequence, so σ ₁〉=σ ₂〉=... 〉=σ _NTXAs mentioned above, the data flow of effectively using is those and the relevant data flow of big singular value.In MIMO pre-coding system 300 can by make up matrix V ' _kRealize that this matrix comprises the V relevant with big singular value _kSome row.For example, for L≤N _TXThe data flow of individual use can obtain pre-coding matrix V ' _k=[V ₁, V ₂..., V _L].Correspondingly, data rows vector s comprises L element.In these cases, part MIMO transmitter 302 can be communicated by letter with emission precoding module 314, needs V with decision _kHow many row make up pre-coding matrix V ' _kThe quantity of data streams equals at V _k' in the quantity of the row that use.L≤N _TXThe pre-coding matrix V ' of row _kUse refers to is exactly that order reduces (reduced-rank) MIMO precoding.

Emission precoding module 314 can be carried out, for example linear transformation x=V ' _k S.Precoding module 316 at receiver 316 can realize linear transformation $y^{\&prime;}={\hat{U}}^{H}y.$

Code book C _dMay comprise complex unitary matrix { Q _q.The code book of wishing may be to comprise the code book that simply can adjust dynamic range.This soluble spin matrix { Q _q, meaning work collection C _dThe absolute angle scope can revise and dispose, and granularity (granularity), just, adjacent matrix Q _qBetween step-length.Revising of described dynamic range can allow described code book to go for very large-scale different channels condition.Especially, code book C _dThe rate of change that can adapt to the wireless channel matrix H.

Fig. 4 shows the flow chart according to the MIMO precoding processing of the embodiment of the invention.With reference to figure 4, provided step 402 to 416.

The MIMO precoding processing begins and step 402.In step 404, can obtain the channel estimating of the send channel between MIMO transmitter and the MIMO receiver.This step can be corresponding to the transfer function of wireless channel 306 in the MIMO pre-coding system 300 that obtains as shown in Figure 3

In step 406, the mode of then using singular value decomposition for example and/or geometric mean to decompose, split-matrix

The channel transfer function of form.This operation for example, can be carried out in as the channel decomposing module among Fig. 3 312.In step 408, the variation of channel is quantized code book to obtain Q _q ⁰In step 410, element $Q_q^0\&Element;C_d$ The feedback channel 320 of index q by as shown in Figure 3 feed back to part MIMO transmitter by part MIMO receiver 304.At MIMO transmitter place, part MIMO transmitter 302 for example for example can be based on the information that is received by feedback by receiver, step 412 can specified data stream quantity L≤N _TXBased on the quantity L of data flow, can be in step 414 by V _kMake up pre-coding matrix V ' _kIn step 416, pre-coding matrix V ' _kCan be applied to the data symbol vectors s of suitable dimension.What in another embodiment of the present invention, the quantity L of employed data flow can be so not frequent determines.For example, as shown in Figure 4, the every N of the quantity L of the data flow that in step 412, is about to be used _LCirculation is determined and/or is upgraded once, and for example keeps constant between the value of upgrading continuously.

According to embodiments of the invention, a kind of method and system that is used for speed compression pre-coding matrix, comprise: code book is quantized in the variation of the channel condition information in the MIMO pre-coding system 300, and produced pre-coding matrix based on described channel condition information at least, as shown in Figure 3 and Figure 4.Described channel condition information can be the relevant singular value with one or more of matrix V.Described matrix V can use singular value decomposition (SVD) or the geometric mean in the channel decomposing module 312 to decompose (GMD) generation.Can be based on relevant singular value, in row or the multiple row of the part MIMO transmitter 302 selection matrix V of place, the row of described selection can merge, to produce pre-coding matrix in emission precoding module 314.Described code book comprises one or more unitary matrice.In this MIMO pre-coding system 300, by feedback channel 320 element index of code book is transmitted into part MIMO transmitter 302 by part MIMO receiver 304, wherein channel condition information changes and quantizes to described code book.The communication system that comprises described MIMO pre-coding system 300 comprises one or more transmitting antenna and one or more reception antenna.Use described pre-coding matrix, at the matrix of the part MIMO of MIMO pre-coding system 300 transmitter 302 neutral line conversion emission precoding module 314 transmitters.

In one embodiment of the invention, can provide a kind of machine readable storage.The computer program of its stored comprises at least one code segment, shown at least one code segment carry out by machine and make described machine carry out above-mentioned steps, to be used for speed compression pre-coding matrix.

The present invention can pass through hardware, software, and perhaps soft, combination of hardware realizes.The present invention can realize with centralized system at least one computer system, perhaps be realized with dispersing mode by the different piece in the computer system that is distributed in several interconnection.Anyly can realize that the computer system of described method or miscellaneous equipment all are applicatory.The combination of software and hardware commonly used can be the general-purpose computing system that computer program is installed, and by installing and carry out described program-con-trolled computer system, it is moved by described method.In computer system, utilize processor and memory cell to realize described method.

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

The present invention describes by several specific embodiments, it will be appreciated by those skilled in the art that, without departing from the present invention, can also carry out various conversion and be equal to alternative the present invention.In addition, at particular condition or concrete condition, can make various modifications to the present invention, and not depart from the scope of the present invention.Therefore, the present invention is not limited to disclosed specific embodiment, and should comprise the whole execution modes that fall in the claim scope of the present invention.

Claims (10)

1, a kind of method that is used for process communication signals is characterized in that, comprising:

The variation of the channel condition information in the multiple-input, multiple-output pre-coding system is quantized on the code book; And

At least produce pre-coding matrix based on described channel condition information.

2, method according to claim 1 is characterized in that, described channel condition information is matrix V or one or more relevant singular value.

3, method according to claim 2 is characterized in that, comprises using singular value decomposition to produce described matrix V.

4, method according to claim 2 is characterized in that, comprises that using geometric mean to decompose produces described matrix V.

5, method according to claim 2 is characterized in that, comprises based on described one or more singular value to select row or a multiple row of described matrix V.

6, method according to claim 5 is characterized in that, comprises that the row that merge described selection or multiple row are to produce described pre-coding matrix.

7, a kind of system that is used for process communication signals is characterized in that, comprising:

One or more circuit in the multiple-input, multiple-output pre-coding system, described circuit is used for:

Code book is quantized in the variation of channel condition information; And

At least produce pre-coding matrix based on described channel condition information.

8, system according to claim 7 is characterized in that, described channel condition information is matrix V or one or more relevant singular value.

9, system according to claim 8 is characterized in that, described one or more circuit uses singular value decomposition to produce described matrix V.

10, system according to claim 8 is characterized in that, described one or more circuit uses geometric mean to decompose and produces described matrix V.

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