CN101316156B - Method, device and system for choosing pre-coding matrix in MIMO system - Google Patents

Abstract

The embodiment of the invention discloses a method, equipment and system for selecting a precoding matrix from a multi-input multi-output system, which belongs to the communication field. The method includes calculating the expected precoding matrix; selecting a precoding matrix which has the shortest euclidean distance with the expected precoding matrix, using the precoding matrix as a feedback precoding matrix of the multi-input multi-output system and feeding back the feedback precoding matrix. The equipment includes a computation module, a selection module and a feedback module. The system includes equipment at the receiving end and equipment at the transmitting end. The invention selects the feedback precoding matrix of the multi-input multi-output system according to the euclidean distance between the precoding matrix with concentrated code book and the expected precoding matrix, and the feedback precoding matrix can be selected in any case.

Description

Choose method, equipment and the system of pre-coding matrix in the multi-input multi-output system

Technical field

The present invention relates to the communications field, choose method, equipment and the system of pre-coding matrix in particularly a kind of multi-input multi-output system.

Background technology

In closed-loop MIMO (Multiple-Input Multiple-Output, multiple-input and multiple-output) system, precoding (Precoding) method can improve power system capacity effectively, reduces and disturbs, and improves performance, is a kind of very important multi-antenna technology.Suppose that mimo system disposes N _TIndividual transmitting antenna and N _RIndividual reception antenna, the data flow x that launch has M _T(M _T≤N _T) road; Then so-called precoding is exactly that transmitting terminal carries out launching after the weighting to x with a pre-coding matrix W again; And W feeds back to transmitting terminal by receiving terminal, and in order to guarantee the launch mass of system, the choosing of receiving terminal pre-coding matrix just becomes in the practical application a very important problem.

In the prior art, the choosing of pre-coding matrix can be divided into pre-coding matrix in the single-carrier system choose with multicarrier system in the choosing of pre-coding matrix.In single-carrier system, based on the singular value decomposition pre-coding matrix of Channel Transmission matrix to choose criterion following:

$W_{\mathrm{OPT}}=\arg \underset{P\∈\mathrm{\Ω}(N_T,M_T,L)}{\min }{d}_{\mathrm{cdl}}^2(P,\tilde{V})$

Wherein, W _OPTExpression feedback pre-coding matrix (optimum pre-coding matrix), P representes the pre-coding matrix that code book is concentrated,

The pre-coding matrix (desirable pre-coding matrix) of expression expection,

It is matrix

Between string (Chordal) distance square, arg representes to make The minimum pre-coding matrix P of value.

Can find out that from above-mentioned pre-coding matrix the single-carrier system chooses the chordal distance definition cost function that the core of criterion is based on matrix, shown in (1):

$d_{\mathrm{cdl}}^2(P,\tilde{V})=1/2{\left|\right|\tilde{V}{\tilde{V}}^H-{\mathrm{PP}}^H\left|\right|}^2=M_T-{\left|\right|P^H\tilde{V}\left|\right|}_F^2=M_T-\mathrm{tr}\left({\tilde{V}}^H{\mathrm{PP}}^H\tilde{V}\right)---\left(1\right)$

Wherein, the mark of tr () representing matrix, () ^HThe expression conjugate transpose, || || _FThe Frobenius norm of representing matrix is called Euclid (euclidean) norm again, and it is defined as

And the pre-coding matrix P that given code book is concentrated works as M _T=N _TBe that the data streams number is a unitary matrix when equaling number of transmit antennas, satisfy PP ^H=I can be found out by (1) formula, and the above-mentioned in this case criterion of choosing obtains identical cost function value to pre-coding matrix arbitrarily, thereby can't select the feedback pre-coding matrix.

When in multicarrier system, choosing pre-coding matrix; The pre-coding matrix at the K number of sub-carrier place between nK+1 number and (n+1) K work song carrier wave all equals the pre-coding matrix at nK+1 work song carrier wave place; And the pre-coding matrix at nK+1 work song carrier wave place is to choose according to the criterion of choosing of single carrier pre-coding matrix; Make selected pre-coding matrix can not well reflect the characteristic of channel at this K number of sub-carrier place like this, cause systematic function undesirable.

In sum, in realizing process of the present invention, the inventor finds to exist at least in the above-mentioned prior art following shortcoming:

When the choosing method of existing pre-coding matrix equals number of transmit antennas at the data streams number, can not select the feedback pre-coding matrix.

Summary of the invention

Select the feedback pre-coding matrix in order to equal number of transmit antennas at the data streams number, the embodiment of the invention provides method, equipment and the system that chooses pre-coding matrix in a kind of multi-input multi-output system.Said technical scheme is following:

The embodiment of the invention provides the method for choosing pre-coding matrix in a kind of multi-input multi-output system, and said method comprises:

Calculate the pre-coding matrix of expection;

Choose and the minimum pre-coding matrix of the Euclidean distance of the pre-coding matrix of said expection,, and feed back said feedback matrix the feedback pre-coding matrix of said pre-coding matrix as multi-input multi-output system;

Wherein, calculating the pre-coding matrix of expecting is specially:

If mimo system disposes N _TIndividual transmitting antenna and N _RIndividual reception antenna, the data flow x that launch has M _T(M _T≤N _T) road;

Singular value decomposition based on the transmission coefficient H of channel is H=UDV ^H, wherein

Be unitary matrix,

Be unitary matrix, submatrix

Preceding M by matrix V _TRow are formed,

Be singular value matrix, then the pre-coding matrix of expection is chosen for

Choose with the minimum pre-coding matrix of the Euclidean distance of the pre-coding matrix of said expection and be specially:

With W _OPTThe feedback pre-coding matrix that expression is chosen P representes the pre-coding matrix that code book is concentrated,

The pre-coding matrix P that the expression code book is concentrated and the pre-coding matrix of expection

Between Euclidean distance, choosing of code book collection depends on N _TAnd M _TAnd the number L of bits of feedback, with Ω (N _T, M _T, L) the expression data streams is M _TRoad, transmitting antenna are N _TThe road contains 2 ^LThe code book collection of individual pre-coding matrix.

The embodiment of the invention also provides a kind of equipment of choosing pre-coding matrix, and said equipment comprises:

Computing module is used to calculate the pre-coding matrix of expection;

Choose module, be used to choose the minimum pre-coding matrix of Euclidean distance of the pre-coding matrix of the expection that calculates with said computing module, the feedback pre-coding matrix of said pre-coding matrix as multi-input multi-output system;

Wherein, computing module is specially:

If mimo system disposes N _TIndividual transmitting antenna and N _RIndividual reception antenna, the data flow x that launch has M _T(M _T≤N _T) road;

Singular value decomposition based on the transmission coefficient H of channel is H=UDV ^H, wherein

Be unitary matrix,

Be unitary matrix, submatrix

Preceding M by matrix V _TRow are formed,

Be singular value matrix, then the pre-coding matrix of expection is chosen for

Choosing module is specially:

With W _OPTThe feedback pre-coding matrix that expression is chosen

P representes the pre-coding matrix that code book is concentrated, The pre-coding matrix P that the expression code book is concentrated and the pre-coding matrix of expection

Between Euclidean distance, choosing of code book collection depends on N _TAnd M _TAnd the number L of bits of feedback, with Ω (N _T, M _T, L) the expression data streams is M _TRoad, transmitting antenna are N _TThe road contains 2 ^LThe code book collection of individual pre-coding matrix.

The embodiment of the invention also provides a kind of system that chooses pre-coding matrix, and said system comprises:

Receiving device, said receiving device specifically comprises:

Computing module is used to calculate the pre-coding matrix of expection;

Choose module, be used to choose the minimum pre-coding matrix of Euclidean distance of the pre-coding matrix of the expection that calculates with said computing module, the feedback pre-coding matrix of said pre-coding matrix as multi-input multi-output system;

Feedback module is used to feed back the said feedback pre-coding matrix that module is chosen of choosing;

Wherein, computing module is specially:

If mimo system disposes N _TIndividual transmitting antenna and N _RIndividual reception antenna, the data flow x that launch has M _T(M _T≤N _T) road;

Singular value decomposition based on the transmission coefficient H of channel is H=UDV ^H, wherein

Be unitary matrix,

Be unitary matrix, submatrix

Preceding M by matrix V _TRow are formed,

Be singular value matrix, then the pre-coding matrix of expection is chosen for

Choosing module is specially:

With W _OPTThe feedback pre-coding matrix that expression is chosen

P representes the pre-coding matrix that code book is concentrated, The pre-coding matrix P that the expression code book is concentrated and the pre-coding matrix of expection Between Euclidean distance, choosing of code book collection depends on N _TAnd M _TAnd the number L of bits of feedback, with Ω (N _T, M _T, L) the expression data streams is M _TRoad, transmitting antenna are N _TThe road contains 2 ^LThe code book collection of individual pre-coding matrix;

Transmitting end equipment is used for according to the feedback pre-coding matrix of said receiving device feedback the emission data being carried out precoding.

The beneficial effect of the technical scheme that the embodiment of the invention provides is:

The embodiment of the invention is chosen the feedback pre-coding matrix through the size of the Euclidean distance between the pre-coding matrix of the pre-coding matrix concentrated according to code book and expection; Can under any situation, select the feedback pre-coding matrix of mimo system; When the size of the chordal distance between the pre-coding matrix of having avoided concentrating through code book in the prior art and the pre-coding matrix of expection is chosen the feedback pre-coding matrix, equal to select under the number of transmit antennas purpose situation problem of feeding back pre-coding matrix at the data streams number.

Description of drawings

Fig. 1 is the structure chart that carries out pre-coding matrix mimo system when choosing that the embodiment of the invention 1 provides;

Fig. 2 is a flow chart of choosing the method for pre-coding matrix in the multi-input multi-output system that provides of the embodiment of the invention 1;

Fig. 3 be the embodiment of the invention 2 provide multicarrier the time choose the flow chart of the method for pre-coding matrix in the multi-input multi-output system;

Fig. 4 be the embodiment of the invention 3 provide another kind of multicarrier the time choose the flow chart of the method for pre-coding matrix in the multi-input multi-output system;

Fig. 5 is the structural representation of the equipment of choosing pre-coding matrix that provides of the embodiment of the invention 4;

Fig. 6 is the structural representation that another kind that the embodiment of the invention 4 provides is chosen the equipment of pre-coding matrix;

Fig. 7 is the structural representation of the system that chooses pre-coding matrix that provides of the embodiment of the invention 5.

Embodiment

For making the object of the invention, technical scheme and advantage clearer, embodiment of the present invention is done to describe in detail further below in conjunction with accompanying drawing.

Referring to Fig. 1, carry out pre-coding matrix when choosing, the structure chart of mimo system for concentrating at code book based on the Channel Transmission matrix when receiving terminal; The general process of mimo system precoding is: receiving terminal estimates the Channel Transmission matrix H earlier, chooses criterion according to preset pre-coding matrix again and chooses suitable pre-coding matrix W, and this pre-coding matrix is fed back to transmitting terminal as the feedback pre-coding matrix through feedback channel (Feedback Channel); Transmitting terminal carries out precoding with this pre-coding matrix to the emission data of back; Especially, in WIMAX (Worldwide interoperability for Microwave Access, micro-wave access to global intercommunication) system; Receiving terminal is MS (Mobile Station; Travelling carriage), transmitting terminal is BS (Base Station, base station).

The feedback pre-coding matrix is from a given set (code book collection), to choose, and all known this set of transmitting terminal and receiving terminal so only needs the numbering of feedback pre-coding matrix in this set to get final product.Choosing of code book collection depends on N _TAnd M _TAnd the number L of bits of feedback, with Ω (N _T, M _T, L) the expression data streams is M _TRoad, transmitting antenna are N _TThe road contains 2 ^LThe code book collection of individual pre-coding matrix, the numbering that in when feedback, only needs feedback pre-coding matrix W to concentrate at code book promptly only needs L bit of feedback to get final product.

In multicarrier system; Can adopt a pre-coding matrix by each subcarrier; But need the bit number of feedback can be very big like this, and up feedback bandwidth all be limited with speed, therefore feeds back total bit number in order to reduce; Pre-coding matrix that can a feedback fraction subcarrier place, and then through certain method (for example: interpolation) obtain the pre-coding matrix at each subcarrier place.

The number of supposing the multicarrier system sub-carriers is N, and the shared identical code book collection Ω (N of all subcarriers _T, M _T, L),, make the used pre-coding matrix of adjacent K (K|N) number of sub-carrier identical in order to reduce feedback bits, parameter K (K|N) is the renewal step-length of pre-coding matrix; At the pre-coding matrix W that confirms on the K work song carrier wave _kAfter, the pre-coding matrix W on the K+1 work song carrier wave _K+1Need in whole code book collection Ω, not search for, only need be in set omega _K={ W ∈ Ω: d _Cdl(W, W _K)＜δ _KIn search get final product, it is following to choose the detailed process of feeding back pre-coding matrix in the multicarrier system:

1), obtains pre-coding matrix W with whole code book collection Ω search to the 1st work song carrier wave ₁

2) to i (i=2,3 ..., K) work song carrier wave still uses pre-coding matrix W ₁, i.e. W _i=W ₁(i=2,3 ..., K);

3) to nK+1 (n=1) work song carrier wave, at pre-coding matrix W _NKNeighborhood Ω _NKMiddle search pre-coding matrix W _NK+1, neighborhood Ω _NKBy code book collection Ω middle distance W _NKNearest 2 ^qIndividual element is formed, and wherein parameter q is used for confirming the search set sizes..

4) to nK+2, nK+3 ..., (n+1) K work song carrier wave still uses pre-coding matrix W _NK+1, i.e. W _NK+i=W _NK+1, i=2 wherein, 3 ..., K;

To n=2,3 ..., N/K-1 repeats above-mentioned 3) and 4).

When the embodiment of the invention is chosen pre-coding matrix in mimo system; The size of the Euclidean distance between the pre-coding matrix of concentrating according to code book and the pre-coding matrix of expection is chosen the feedback pre-coding matrix, can under any situation, can both select the feedback pre-coding matrix that can reflect the characteristic of channel.

The embodiment of the invention provides the method for choosing pre-coding matrix in a kind of multi-input multi-output system, and this method comprises:

Calculate the pre-coding matrix of expection;

Choose and the minimum pre-coding matrix of the Euclidean distance of the pre-coding matrix of above-mentioned expection,, and feed back this pre-coding matrix the feedback pre-coding matrix of this pre-coding matrix as multi-input multi-output system.

Embodiment 1

Present embodiment is chosen for example with the feedback pre-coding matrix of single-carrier system and describes; In the present embodiment after calculating the pre-coding matrix of expection; The size of the Euclidean distance between the pre-coding matrix of concentrating according to code book and the pre-coding matrix of expection is chosen the feedback pre-coding matrix; Referring to Fig. 2, the embodiment of the invention provides the method for choosing pre-coding matrix in a kind of multi-input multi-output system, specifically comprises:

101: the pre-coding matrix that calculates expection.

Wherein, the process of the pre-coding matrix of calculating expection is specific as follows:

Referring to Fig. 1, suppose that mimo system disposes N _TIndividual transmitting antenna and N _RIndividual reception antenna, the data flow x that launch has M _T(M _T≤N _T) road, wherein

Satisfy E (xx ^H)=E _sI, wherein, E representes energy, E _sBe energy, value is 1, I representation unit battle array.Through the actual transmission vector after the precoding be the relation of

z and pre-coding matrix W shown in (2) formula:

z＝Wx (2)

Wherein,

receives the signal frequency-domain model shown in (3) formula:

r＝Hz+n＝HWx+n (3)

Wherein,

For receiving vector,

h _IjBe the transmission coefficient of channel between j transmitting antenna and the i reception antenna, can obtain through channel estimating that n is a component noise vector independently mutually, receiving between signal and the noise is independently, promptly satisfies E (nn ^H)=N ₀I, E (nx ^H)=0.

The singular value decomposition of supposing the transmission coefficient H of channel is H=UDV ^H, wherein

Be unitary matrix,

Be unitary matrix, submatrix

Preceding M by matrix V _TRow are formed,

Be singular value matrix, then the pre-coding matrix W of expection is chosen for

102: choose code book and concentrate the pre-coding matrix apart from minimum, with the feedback pre-coding matrix of this pre-coding matrix as multi-input multi-output system with the Euclid of the pre-coding matrix of expection.

In practical application; The number of the pre-coding matrix that code book is concentrated is confirmed; Can calculate the Euclid distance of the pre-coding matrix of each concentrated pre-coding matrix of code book and expection respectively; And then according to the size of the Euclid distance value that calculates, choose code book and concentrate the pre-coding matrix apart from minimum with the Euclid of the pre-coding matrix of expection, with this pre-coding matrix as the feedback pre-coding matrix.

With W _OPTThe feedback pre-coding matrix that expression is chosen, in sum, choose in the present embodiment shown in the functional expression of criterion shown in (4) formula that feeds back pre-coding matrix:

$W_{\mathrm{OPT}}=\arg \underset{P\∈\mathrm{\Ω}(N_T,M_T,L)}{\min }d(P,\tilde{V})---\left(4\right)$

Wherein, P representes the pre-coding matrix that code book is concentrated,

Euclid distance between the pre-coding matrix

of the pre-coding matrix P that concentrates of expression code book and expection.

103: feed back the feedback pre-coding matrix of selecting to transmitting terminal.

104: after transmitting terminal is received the feedback pre-coding matrix, the emission data are carried out precoding according to this feedback pre-coding matrix.

To sum up can find out; The feedback precoding battle array of the single-carrier system that present embodiment provides is chosen criterion and is not only applicable to the situation that the data streams number equals number of transmit antennas; Can also be applied to other feedback precoding battle array based on the code book collection and choose, promptly the concentrated pre-coding matrix P of code book can not satisfy PP ^H=I.

Present embodiment is in single-carrier system; Choose the feedback pre-coding matrix of multi-input multi-output system through the size of the Euclidean distance between the pre-coding matrix of the pre-coding matrix concentrated according to code book and expection, avoided to select when the data streams number equals number of transmit antennas in the prior art problem of feeding back pre-coding matrix.

Embodiment 2

Present embodiment is chosen for example with the pre-coding matrix of multicarrier system and describes; In the present embodiment; Choose the method for feedback pre-coding matrix according to single carrier and choose the feedback pre-coding matrix of each subcarrier in the K number of sub-carrier, then with the feedback pre-coding matrix of most number feedback pre-coding matrix as the K number of sub-carrier.Referring to Fig. 3, the embodiment of the invention provides the method for choosing pre-coding matrix in a kind of multi-input multi-output system, specifically comprises:

201: for nK+1 number in the multicarrier system to (n+1) K (n=0; 1;) number between the K number of sub-carrier, identical pre-coding matrix choosing method when adopting with single-carrier system is chosen the feedback pre-coding matrix of each subcarrier from the code book collection; This process repeats no more with identical described in the embodiment 1 here.

202: according to K the feedback pre-coding matrix of choosing in 201, choose the feedback pre-coding matrix of most number, with the feedback pre-coding matrix of selecting as nK+1 number to (n+1) K (n=0,1 ...) number between the feedback pre-coding matrix of K number of sub-carrier.

For example, suppose that the pre-coding matrix that code book is concentrated has m, is respectively P ₁, P ₂..., P _m, for the K subcarrier between No. 1 to K number, the feedback pre-coding matrix of each subcarrier of choosing is respectively P ₁, P ₁, P ₂, P _m..., P ₁If, P ₁Most number, then with P ₁Feedback pre-coding matrix as the K number of sub-carrier between No. 1 to K number.

In sum, the pre-coding matrix of multicarrier is chosen shown in the functional expression of criterion shown in (5) formula in the present embodiment:

$W_{\mathrm{OPT}}=\arg \underset{P\∈\mathrm{\Ω}(N_T,M_T,L)}{\max }P{r}_{\mathrm{nK}+1}^{(n+1)K}\left(P\right)---\left(5\right)$

Wherein, representes nK+1 number in the K number of sub-carrier between (n+1) K work song carrier wave; The number of the pre-coding matrix P that chooses promptly is the number of subcarrier of the feedback pre-coding matrix of single carrier with P.

203: feed back the feedback pre-coding matrix of selecting to transmitting terminal.

204: after transmitting terminal is received the feedback pre-coding matrix, the emission data are carried out precoding according to this feedback pre-coding matrix.

Present embodiment is when multicarrier system; Choose the method for pre-coding matrix during at first according to single carrier; Adjacent K number of sub-carrier is fed back choosing of pre-coding matrix separately earlier, so under any circumstance can select the feedback pre-coding matrix of each subcarrier; In addition, will be chosen the feedback pre-coding matrix of the maximum feedback pre-coding matrix of number of times as adjacent K number of sub-carrier, the feedback pre-coding matrix of choosing like this can be taken into account the characteristic of channel of K number of sub-carrier on probability meaning, improves systematic function.

Embodiment 3

In multicarrier system; The foregoing description 2 is after selecting the feedback pre-coding matrix of each subcarrier; Choose the feedback pre-coding matrix of multicarrier system from the angle of probability; Present embodiment is chosen the feedback pre-coding matrix from the angle of distance, promptly in calculating the K number of sub-carrier behind the pre-coding matrix of the expection of each subcarrier, chooses and the feedback pre-coding matrix of the minimum pre-coding matrix of the pre-coding matrix overall distance of K expection as the K number of sub-carrier.Referring to Fig. 4, the embodiment of the invention also provides the method for choosing pre-coding matrix in the another kind of multi-input multi-output system, specifically comprises:

301: for nK+1 number in the multicarrier system to (n+1) K (n=0,1 ...) number between the K number of sub-carrier, calculate the pre-coding matrix of the expection of each subcarrier, 101 is said identical among this process and the embodiment 1, repeats no more here.

302: choose code book concentrate with 301 in the overall Euclid of K pre-coding matrix calculating apart from the pre-coding matrix of minimum, with this pre-coding matrix as nK+1 number feedback pre-coding matrix to the K number of sub-carrier between (n+1) K number.

In practical application; The number of the pre-coding matrix that code book is concentrated is confirmed; Can calculate the Euclid distance of the pre-coding matrix of each concentrated pre-coding matrix of code book and K expection respectively; And then the p norm of the distance vector that constitutes according to the K that calculates Euclid distance value; Choose the minimum pre-coding matrix of the p norm that makes distance vector as nK+1 number feedback pre-coding matrix according to the size of p norm, in the present embodiment, weigh overall Euclid distance with the p norm of vector to the K number of sub-carrier between (n+1) K number.

In sum, the pre-coding matrix of multicarrier is chosen shown in the functional expression of criterion shown in (6) formula in the present embodiment:

$W_{\mathrm{OPT}}=\arg \underset{P\∈\mathrm{\Ω}(N_T,M_T,L)}{\min }{\left|\right|d\left|\right|}_p.---\left(6\right)$

Wherein, $d={[d(P,{\tilde{V}}_{\mathrm{NK}+1}),d(P,{\tilde{V}}_{\mathrm{NK}+2}),...,d(P,{\tilde{V}}_{(n+1)K})]}^T,$ Be the distance vector of K Euclid distance value formation, || || _pBe the p norm of vector, p value 1,2 or ∞, () ^TThe expression transposition.

303: feed back the feedback pre-coding matrix of selecting to transmitting terminal.

304: after transmitting terminal is received the feedback pre-coding matrix, the emission data are carried out precoding according to this feedback pre-coding matrix.

Present embodiment is when multicarrier system; At first adjacent K number of sub-carrier is calculated the pre-coding matrix of the expection of each subcarrier; The overall Euclid of the pre-coding matrix of the K that chooses then and calculate expection is apart from the encoder matrix of the minimum feedback pre-coding matrix as adjacent K number of sub-carrier; The feedback pre-coding matrix of choosing like this can be taken into account the characteristic of channel of K number of sub-carrier, improves systematic function.

Further; In the foregoing description 1, embodiment 2 and embodiment 3, the feedback pre-coding matrix of mimo system is concentrated from code book and is chosen all known this set of transmitting terminal and receiving terminal; Like this after selecting the feedback pre-coding matrix; The numbering that only needs this feedback pre-coding matrix of feedback to concentrate at code book gets final product, and this process is identical with prior art, repeats no more here.

In addition, the foregoing description 2 and the method for in multicarrier system, choosing the feedback pre-coding matrix that embodiment 3 provides are not only applicable to the WiMAX system, also can be used for other multicarrier system.

Embodiment 4

Referring to Fig. 5, the embodiment of the invention provides a kind of equipment of choosing pre-coding matrix, and this equipment comprises:

Computing module 401 is used to calculate the pre-coding matrix of expection;

Choose module 402, be used to choose the minimum pre-coding matrix of Euclidean distance of the pre-coding matrix of the expection that calculates with computing module 401, the feedback pre-coding matrix of this pre-coding matrix as multi-input multi-output system;

Feedback module 403 is used to feed back and chooses the feedback pre-coding matrix that module 402 is chosen.

Further, when multicarrier system, aforementioned calculation module 401 can specifically be used for for nK+1 number to the K number of sub-carrier between (n+1) K number, calculate the pre-coding matrix of the expection of each subcarrier;

Correspondingly, the above-mentioned module 402 of choosing can specifically comprise:

Subcarrier is chosen unit 4021, is used to choose the feedback pre-coding matrix of the minimum pre-coding matrix of the Euclidean distance of pre-coding matrix of expection of each subcarrier that calculates with computing module 401 as each subcarrier;

Choose unit 4022; Be used for choosing K the optimum pre-coding matrix that unit 4021 selects according to subcarrier; Choose the pre-coding matrix of most number, with the feedback pre-coding matrix of selecting as nK+1 number feedback pre-coding matrix to the K number of sub-carrier between (n+1) K number.

Further; Can also choose the feedback pre-coding matrix of multi-input multi-output system from the angle of the overall Euclidean distance of the pre-coding matrix of the expection of pre-coding matrix and each subcarrier; Referring to Fig. 6; Present embodiment also provides the another kind of equipment of choosing pre-coding matrix, and choosing module 402 in this equipment can also specifically comprise:

Choose unit 4023; Be used to choose the minimum pre-coding matrix of overall Euclidean distance of the pre-coding matrix of calculate with computing module 401 K expection, with this pre-coding matrix as nK+1 number feedback pre-coding matrix to the K number of sub-carrier between (n+1) K number.

Present embodiment calculates the pre-coding matrix of expection through computing module 401; Choosing module 402 then chooses and the minimum pre-coding matrix of the Euclidean distance of the pre-coding matrix of expecting; This pre-coding matrix as the feedback pre-coding matrix, can be avoided when the data streams number equals number of transmit antennas, can not selecting in the prior art problem of feedback pre-coding matrix like this when single-carrier system; In addition; For multicarrier system; With K feedback pre-coding matrix that feeds back the feedback pre-coding matrix of most number in the pre-coding matrix as adjacent K number of sub-carrier; Perhaps will with the feedback pre-coding matrix of the minimum pre-coding matrix of the pre-coding matrix overall distance of K expection as adjacent K number of sub-carrier, the feedback pre-coding matrix of choosing has like this been taken into account the characteristic of channel of K number of sub-carrier, has improved systematic function.

Embodiment 5

Referring to Fig. 7, the embodiment of the invention provides a kind of system that chooses pre-coding matrix, and this system comprises:

Receiving device 501 is used to calculate the pre-coding matrix of expection, and chooses and the minimum pre-coding matrix of Euclidean distance of the pre-coding matrix of expecting, this pre-coding matrix as the feedback pre-coding matrix, and is fed back this feedback pre-coding matrix;

Transmitting end equipment 502 is used for according to the feedback pre-coding matrix of receiving device 501 feedbacks the emission data being carried out precoding.

The equipment of choosing pre-coding matrix that the foregoing description 4 provides can be used as the receiving device 501 in the present embodiment, and further, above-mentioned receiving device 501 specifically comprises:

Computing module 401 is used to calculate the pre-coding matrix of expection;

Choose module 402, be used to choose the minimum pre-coding matrix of Euclidean distance of the pre-coding matrix of the expection that calculates with computing module 401, the feedback pre-coding matrix of this pre-coding matrix as multi-input multi-output system;

Feedback module 403 is used to feed back and chooses the feedback pre-coding matrix that module 402 is chosen.

The size of the Euclidean distance between the pre-coding matrix that the embodiment of the invention is concentrated according to code book through receiving device 501 and the pre-coding matrix of expection is chosen the feedback pre-coding matrix; Can under any situation, select the feedback pre-coding matrix of multi-input multi-output system; Thereby transmitting end equipment 502 can feed back pre-coding matrix according to this carries out precoding to the emission data, has improved the performance of system.

The embodiment of the invention can realize that correspondingly software can store in the storage medium that can read through software, for example, and in the hard disk of computer, floppy disk or the CD.

The above is merely preferred embodiment of the present invention, and is in order to restriction the present invention, not all within spirit of the present invention and principle, any modification of being done, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (3)

1. choose the method for pre-coding matrix in the multi-input multi-output system, it is characterized in that said method comprises:

Calculate the pre-coding matrix of expection;

Choose and the minimum pre-coding matrix of the Euclidean distance of the pre-coding matrix of said expection,, and feed back said feedback pre-coding matrix the feedback pre-coding matrix of said pre-coding matrix as multi-input multi-output system;

Wherein, calculating the pre-coding matrix of expecting is specially:

If mimo system disposes N _TIndividual transmitting antenna and N _RIndividual reception antenna, the data flow x that launch has M _T(M _T≤N _T) road;

Singular value decomposition based on the transmission coefficient H of channel is H=UDV ^H, wherein

Be unitary matrix,

Be unitary matrix, submatrix

Preceding M by matrix V _TRow are formed, Be singular value matrix, then the pre-coding matrix of expection is chosen for

Choose with the minimum pre-coding matrix of the Euclidean distance of the pre-coding matrix of said expection and be specially:

With W _OPTThe feedback pre-coding matrix that expression is chosen

P representes the pre-coding matrix that code book is concentrated,

The pre-coding matrix P that the expression code book is concentrated and the pre-coding matrix of expection

Between Euclidean distance, choosing of code book collection depends on N _TAnd M _TAnd the number L of bits of feedback, with Ω (N _T, M _T, L) the expression data streams is M _TRoad, transmitting antenna are N _TThe road contains 2 ^LThe code book collection of individual pre-coding matrix.

2. an equipment of choosing pre-coding matrix is characterized in that, said equipment comprises:

Computing module is used to calculate the pre-coding matrix of expection;

Choose module, be used to choose the minimum pre-coding matrix of Euclidean distance of the pre-coding matrix of the expection that calculates with said computing module, the feedback pre-coding matrix of said pre-coding matrix as multi-input multi-output system;

Feedback module is used to feed back the said feedback pre-coding matrix that module is chosen of choosing;

Wherein, computing module is specially:

If mimo system disposes N _TIndividual transmitting antenna and N _RIndividual reception antenna, the data flow x that launch has M _T(M _T≤N _T) road;

Singular value decomposition based on the transmission coefficient H of channel is H=UDV ^H, wherein Be unitary matrix,

Be unitary matrix, submatrix

Preceding M by matrix V _TRow are formed, Be singular value matrix, then the pre-coding matrix of expection is chosen for

Choosing module is specially:

With W _OPTThe feedback pre-coding matrix that expression is chosen

P representes the pre-coding matrix that code book is concentrated,

The pre-coding matrix P that the expression code book is concentrated and the pre-coding matrix of expection

Between Euclidean distance, choosing of code book collection depends on N _TAnd M _TAnd the number L of bits of feedback, with Ω (N _T, M _T, L) the expression data streams is M _TRoad, transmitting antenna are N _TThe road contains 2 ^LThe code book collection of individual pre-coding matrix.

3. a system that chooses pre-coding matrix is characterized in that, said system comprises:

Receiving device, said receiving device specifically comprises:

Computing module is used to calculate the pre-coding matrix of expection;

Choose module, be used to choose the minimum pre-coding matrix of Euclidean distance of the pre-coding matrix of the expection that calculates with said computing module, the feedback pre-coding matrix of said pre-coding matrix as multi-input multi-output system;

Feedback module is used to feed back the said feedback pre-coding matrix that module is chosen of choosing;

Wherein, computing module is specially:

If mimo system disposes N _TIndividual transmitting antenna and N _RIndividual reception antenna, the data flow x that launch has M _T(M _T≤N _T) road;

Singular value decomposition based on the transmission coefficient H of channel is H=UDV ^H, wherein

Be unitary matrix,

Be unitary matrix, submatrix Preceding M by matrix V _TRow are formed,

Be singular value matrix, then the pre-coding matrix of expection is chosen for

Choosing module is specially:

With W _OPTThe feedback pre-coding matrix that expression is chosen P representes the pre-coding matrix that code book is concentrated,

The pre-coding matrix P that the expression code book is concentrated and the pre-coding matrix of expection Between Euclidean distance, choosing of code book collection depends on N _TAnd M _TAnd the number L of bits of feedback, with Ω (N _T, M _T, L) the expression data streams is M _TRoad, transmitting antenna are N _TThe road contains 2 ^LThe code book collection of individual pre-coding matrix;

Transmitting end equipment is used for according to the feedback pre-coding matrix of said receiving device feedback the emission data being carried out precoding.

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