CN101635612B - Precoding code book constructing method and precoding code book constructing device of multi-input multi-output system - Google Patents

Abstract

The invention discloses a precoding code book constructing method of a multi-input multi-output system, comprising the following steps: selecting N 4*4 first orthogonal matrixes Un, and selecting N second orthogonal matrixes Kn; generating N 8*8 matrixes Mn according to the selected Un and Kn in a manner of a Kronecker product or analog Kronecker product; and selecting a row or multiple rows of matrixes Mn to construct partial code words in a subcode book of each rank under 8 antennae. The invention also discloses a precoding code book constructing device of a multi-input multi-output system. The method and the device enables the designed code book to satisfy an orthogonal characteristic, a constant modulus characteristic and a 8 PSK characteristic in 8 antennae and have better performance under correlation channels and noncorrelation channels.

Description

Precoding codebook building method and the device of multi-input multi-output system

Technical field

The present invention relates to code book constructing technology, refer to especially precoding codebook building method and the device of a kind of multiple-input and multiple-output (MIMO) system.

Background technology

At radio communication multiple-input and multiple-output (MIMO, Multiple-Input Multiple-Out-put) in system, if all use many antennas at transmitting terminal and receiving terminal, can take the mode of spatial reuse to obtain higher speed: on the different antennae position of the identical running time-frequency resource of transmitting terminal, to launch different data, so just can improve transmission rate.Can obtain by channel estimating the channel information (CSI, Channel State Information) between each dual-mode antenna at receiving terminal, these CSI can be formed to multiple channel matrixes.Because receiving terminal has obtained the gone through channel matrix that transmits, even therefore different data of each antenna transmission, after channel matrix, receiving terminal still can solve transmitting datas different on each antenna.

With respect to utilizing channel matrix directly to solve the method for transmitting data on each antenna, a kind of means of enhancing are to adopt transmitting precoding technique.Concept in transmitting terminal definition " layer ": on same running time-frequency resource, every layer can transmit different data modulation symbol (being data), and the number of plies equals the order (Rank) of the channel matrix that this running time-frequency resource is corresponding.Data on layer are carried out to precoding processing, be mapped to after antenna and send to receiving terminal through air traffic channel again.If can learn the CSI of complete and accurate at transmitting terminal, can carry out singular value decomposition (Singular Value Decomposition) to the channel matrix of CSI composition so, then using the matrix of the right characteristic vector composition decompositing as pre-coding matrix, based on this matrix, each layer data is carried out to precoding processing.

Based on complete and accurate CSI, can accomplish optimum precoding processing to each layer data.But CSI often only could obtain at receiving terminal directly and accurately, and wants Obtaining Accurate CSI can only carry out by receiving terminal the mode of CSI feedback to transmitting terminal at transmitting terminal.This shows, in precoding technique, an important problem is exactly how to obtain, utilize CSI.In the standard of current main flow, the channel capacity that mimo system offers CSI feedback is all limited, because the feedback quantity of whole CSI is very large, therefore the feedback method of main flow is all the mode based on code book, and the content of feedback is the matrix of the right characteristic vector composition of channel matrix, i.e. pre-coding matrix.

Precoding general principle based on code book feedback is: the channel overhead bit number of supposing feedback CSI is Bbps/Hz (B is positive integer).So can with the number of code word be N=2 ^b; The quantized value of all pre-coding matrixes forms code book fN is code word, and transmitting terminal and receiving terminal are preserved this code book jointly.Every secondary channel is realized to H, receiving terminal according to certain criterion from optimum code word F of middle selection _n, its corresponding code word sequence number N is fed back to transmitting terminal.Transmitting terminal finds corresponding code word according to code word sequence number, and the data symbol block sending is carried out to precoding.

In general, can further be divided into the sub-codebook that multiple Rank are corresponding, each Rank can corresponding multiple values quantizes the pre-coding matrix that the right characteristic vector of the channel matrix under this Rank forms.Because Rank and the right characteristic vector number of non-zero of channel matrix equate, therefore, code word when in general Rank is N all can have N row, so we can be code book be divided into multiple sub-codebooks by Rank, as shown in table 1:

Table 1

In the time can obtaining CSI to entirely accurate, the performance of precoding is best.Due to the restriction of feedback overhead (for the channel capacity of feeding back), can only adopt CSI feedback based on code book and the precoding of transmitted data symbols.In actual mimo system, the design of code book is extremely important, and an important goal of code book design ensures that quantization error is as far as possible little exactly, and code book realization is simple, and expense is reasonable, and memory space is little.

In addition, consider the application that some are concrete, code book design also should meet following characteristic:

1, constant modulus property: code book when design considers to make the row vector in each pre-encoding codeword of code book to have constant modulus property, can make after precoding, the power distributing on each antenna equates, avoid the increase of peak-to-average force ratio index (PAPR), can make the power amplification balance between each power amplifier (PA, Power Amplifier).Therefore, the basic demand of constant modulus property is that every a line of pre-coding matrix has identical mould value, and in the time of Rank=1, constant modulus property requires the mould value of each element to equate.

2, orthogonal property: channel matrix is carried out after SVD decomposition, and each the right characteristic vector obtaining must be orthogonal.The design of code book is the right characteristic vector direction for match channels matrix, and therefore, the code word of design also should meet this feature, and in the pre-encoding codeword of Rank > 1, each column vector should be all orthogonal.Orthogonal property is an important principle, in any case design codebooks, this characteristic is necessarily to need to meet, the quantified precision of guarantee code book like this.

3,8PSK characteristic: consider the complexity that realizes sending and receiving end precoding processing, therefore need the value that limits each element to select from point corresponding to 8 phase shift keyings (PSK, Phase Shift Keying), be called 8PSK characteristic.Limit code book and have 8PSK characteristic, before code book being normalized, the value of each element just can only be from the letter collection of 8PSK: $\{1,-1,j,-j,\frac{1+j}{\sqrt{2}},\frac{-1+j}{\sqrt{2}},\frac{1-j}{\sqrt{2}},\frac{-1-j}{\sqrt{2}}\}$ Middle selection.

In code book when design,, do not meet any one in above-mentioned characteristic and all can bring corresponding defect, do not meet orthogonal property and can make quantization error very large; Do not meet constant modulus property and can make unbalanced power between the each PA of antenna; Not meeting 8PSK characteristic can make the complexity of transmitting terminal precoding increase.Now, can under some scene, consider that the value of the each element of increase is 0, can not affect like this complexity of precoding.

At present, in prior art about the following several schemes of being designed with of code book:

One, existing mainstream standard third generation partner program (3GPP, 3rd Generation PartnershipProject) Long Term Evolution (LTE, Long Term Evolution) adopt the code book based on Household conversion in 4 antennas (4Tx) the code book design of LTE (R8), its thought is: choose 16 vector u ₀～u ₁₅; These 16 vectors are carried out to Household conversion and obtain Household matrix W _n(W ₀～W ₁₅), $W_n=I-2u_n{u}_n^H/u_n^H{u}_n$ (n is 0～15); From W _nthe all or part of row of middle extraction form the code book under each Rank

This method is in code book when design of 4Tx, by the choosing of u vector, can well ensure orthogonal property, constant modulus property, 8PSK characteristic, and it is few to have memory space, the advantage that performance is good.But in the time of the code book design of 8Tx, the method can not meet constant modulus property, the power amplifier imbalance between antenna, therefore the method can not well be applied to the code book design of 8Tx.

Two, the code book design philosophy based on other conversion, as the code book design based on discrete Fourier transform (DFT) (DFT), better performances under correlated channels, but under non-correlation channel poor-performing; In the code book design of 8Tx, code book based on DFT conversion still has better performances under the correlated channels under single-polarized antenna, but the shortcoming of poor-performing under the non-correlation channel under the correlated channels under dual polarized antenna and single dual polarized antenna, and do not meet 8PSK characteristic.

At present, in prior art, do not have a kind of scheme and can ensure can meet orthogonal property in the time of design codebooks, constant modulus property, 8PSK characteristic, can meet again and under correlated channels and non-correlation channel, all have good performance.

Summary of the invention

In view of this, main purpose of the present invention is to provide a kind of precoding codebook building method and device of mimo system, make the code book of design meet orthogonal property, constant modulus property, also meets when 8PSK characteristic and under correlated channels and non-correlation channel, all has good performance.

For achieving the above object, technical scheme of the present invention is achieved in that

The precoding codebook building method that the invention provides a kind of multi-input multi-output system, the method comprises:

Choose the first orthogonal matrix U of N individual 4 × 4 _n, and choose N the second orthogonal matrix K _n;

According to the U choosing _nand K _n, construct the matrix M of N 8 × 8 by the mode that Kronecker amasss or similar Kronecker is long-pending _n;

From matrix M _nin choose the part code word in the sub-codebook that row or multiple row generate each order Rank under 8 antennas.

Wherein, described N≤2 ^b, B is the channel overhead bit number of feedback channel information CSI, is positive integer;

A described N U _nfrom orthogonal matrix W _nin choose; Described $W_n=I-2u_n{u}_n^H/u_n^H{u}_n,$ U _nfor vector, comprise u ₀～u ₁₅.

The method further comprises: a described N U _nin comprise k and adapt to the orthogonal matrix of correlated channels, be arranged as O by the size order of call number n ₁, O ₂... O _k, and O ₁, O ₂... O _kfrom described W _nw ₀～W ₇in choose, k≤N.

Described O ₁, O ₂... O _kfrom W ₀～W ₇in choose, be specially:

While needing direction vector to be uniformly distributed in 120 degree, O ₁, O ₂... O _kfrom W ₀～W ₃in choose;

Or, while needing direction vector to be uniformly distributed in 180 degree, O ₁, O ₂... O _kfrom W ₄～W ₇in choose;

Or, O ₁, O ₂... O _kcomprise W ₀～W ₇;

Described direction vector is O ₁, O ₂... O _kthe direction vector that middle first row forms.

A described N K _nbe 2 × 2 orthogonal matrix, or 4 × 4 orthogonal matrix;

K _nwhile being 2 × 2 orthogonal matrix, the corresponding long-pending mode of Kronecker is specially: or

K _nwhile being 4 × 4 orthogonal matrix, the corresponding long-pending mode of similar Kronecker is specially: $\left[\begin{array}{cc}{a}_n{U}_n& c_n{K}_n\\ b_n{U}_n& d_n{K}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{K}_n& c_n{U}_n\\ b_n{K}_n& {\text{d}}_n{U}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{K}_n& c_n{K}_n\\ b_n{U}_n& d_n{U}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{U}_n& c_n{U}_n\\ b_n{K}_n& d_n{K}_n\end{array}\right],$ Described $\left(\begin{array}{cc}{a}_n& c_n\\ b_n& d_n\end{array}\right)$ For orthogonal matrix, a _n, b _n, c _n, d _nfor 8PSK letter collection $\{1,-1,j,-j,\frac{1+j}{\sqrt{2}},\frac{-1+j}{\sqrt{2}},\frac{1-j}{\sqrt{2}},\frac{-1-j}{\sqrt{2}}\}$ In element, or a _n, d _nbe 0 simultaneously, or b _n, c _nbe 0 simultaneously.

When the value of described N is greater than default threshold value, K _nthe matrix of middle coupling non-correlation channel had both comprised 2 × 2 orthogonal matrix, also comprised 4 × 4 orthogonal matrix.

If K _nbe 4 × 4 orthogonal matrix, K _nfrom W ₀～W ₁₅in choose, concrete:

If need to generate the code word that is applicable to correlated channels, K _nfrom W ₀～W ₇in choose;

If need to generate the code word that is applicable to non-correlation channel, K _nfrom W ₈～W ₁₅in choose.

Described K _nwhile being 2 × 2 orthogonal matrix, the method further comprises: described 2 × 2 orthogonal matrix is chosen from following eight kinds of Mathematical Modeling matrixes:

$K_n=\left[\begin{array}{cc}{w}_1& w_1\\ w_2& -w_2\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_2& -w_2\\ w_1& w_1\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_1& w_2\\ w_1& -w_2\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_2& w_1\\ {-w}_2& w_1\end{array}\right],$

$K_n=\left[\begin{array}{cc}{w}_3& {w_4}^{*}\\ -w_4& {w_3}^{*}\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_3& {w_4}^{*}\\ w_4& -{w_3}^{*}\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_3& 0\\ 0& w_4\end{array}\right],$ $K_n=\left[\begin{array}{cc}0& w_3\\ w_4& 0\end{array}\right];$

Wherein, w ₁, w ₂for 8PSK letter collection $\{1,-1,j,-j,\frac{1+j}{\sqrt{2}},\frac{-1+j}{\sqrt{2}},\frac{1-j}{\sqrt{2}},\frac{-1-j}{\sqrt{2}}\}$ In element, w ₃, w ₄collect for 4PSK is alphabetical 1 ,-1, j, the element in-j}.

The method further comprises: described 2 × 2 orthogonal matrix is chosen from the expansion of described eight kinds of Mathematical Modeling matrixes;

The expansion of described eight kinds of Mathematical Modelings, is specially: each row of described matrix are multiplied by the identical or different concentrated element of 8PSK letter; Or every a line of described matrix is multiplied by the identical or different concentrated element of 8PSK letter; Or by described Matrix Multiplication with a constant.

When code word under described generation 8 antennas in the sub-codebook of each order Rank, the method further comprises: according to Nested property, from matrix M _nin choose the part code word in the sub-codebook that row or multiple row generate each order Rank under 8 antennas.

The present invention also provides a kind of precoding codebook constructing apparatus of multi-input multi-output system, and this device comprises: matrix is chosen module, matrix generation module and code book generation module, wherein,

Described matrix is chosen module, for choosing the first orthogonal matrix U of N individual 4 × 4 _n, and N the second orthogonal matrix K _n, and by the U choosing _nand K _noffer described matrix generation module;

Described matrix generation module, the U choosing for basis _nand K _n, generate the matrix M of N 8 × 8 by the mode that Kronecker amasss or similar Kronecker is long-pending _n;

Described code book generation module, for from matrix M _nin choose the code word in the sub-codebook that 1 row or multiple row generate each Rank under 8 antennas.

Described matrix is chosen module and is further used for, from orthogonal matrix W _nin choose N U _n, and $W_n=I-2u_n{u}_n^H/u_n^H{u}_n,$ U _nfor vector, n=0～15;

Described W _nmeet 8 phase shift keying PSK characteristics, constant modulus property and orthogonal property.

Described K _nwhile being 4 × 4 matrix, matrix is chosen module and is further used for, from W _nw ₀～W ₁₅in choose K _n

Described K _nwhile being 2 × 2 matrix, matrix is chosen module and is further used for, and from following eight kinds of Mathematical Modeling matrixes, chooses K _n: $K_n=\left[\begin{array}{cc}{w}_1& w_1\\ w_2& -w_2\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_2& -w_2\\ w_1& w_1\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_1& w_2\\ w_1& -w_2\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_2& w_1\\ {-w}_2& w_1\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_3& {w_4}^{*}\\ -w_4& {w_3}^{*}\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_3& {w_4}^{*}\\ w_4& -{w_3}^{*}\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_3& 0\\ 0& w_4\end{array}\right],$ $K_n=\left[\begin{array}{cc}0& w_3\\ w_4& 0\end{array}\right];$

Wherein, w ₁, w ₂for 8PSK letter collection $\{1,-1,j,-j,\frac{1+j}{\sqrt{2}},\frac{-1+j}{\sqrt{2}},\frac{1-j}{\sqrt{2}},\frac{-1-j}{\sqrt{2}}\}$ In element, w ₃, w ₄collect for 4PSK is alphabetical 1 ,-1, j, the element in-j}.

The precoding codebook structural scheme based on mimo system the invention provides, based on meeting the orthogonal matrix of orthogonal property, constant modulus property and 8PSK characteristic, as Household matrix $W_n=I-2u_n{u}_n^H/u_n^H{u}_n$ Deng choosing the first orthogonal matrix and the second orthogonal matrix, also provide eight kinds of Mathematical Modeling matrixes choosing for the second orthogonal matrix; And the first orthogonal matrix based on choosing and the mode that the second orthogonal matrix amasss by Kronecker or similar Kronecker is long-pending generate required matrix M _n, finally from M _nchoose the code word in the sub-codebook that 1 row or multiple row form each Rank; Due to $W_n=I-2u_n{u}_n^H/u_n^H{u}_n$ Itself meet orthogonal property, constant modulus property and 8PSK characteristic, amass by Kronecker or mode that similar Kronecker is long-pending is expanded the first orthogonal matrix and the second orthogonal matrix, the matrix M that therefore the present invention obtains simultaneously _nalso meet orthogonal property, constant modulus property and 8PSK characteristic.

In addition, in the time selecting the first orthogonal matrix and the second orthogonal matrix, as required can also be from $W_n=I-2u_n{u}_n^H/u_n^H{u}_n$ In select coupling correlated channels or non-correlation channel in orthogonal matrix matrix, so, method of the present invention all has good performance for correlated channels and non-correlation channel; And the code book of structure of the present invention meets Nested property, the follow-up standard of LTE is compatible good relatively, can effectively utilize the existing memory space of LTE, increase a small amount of storage and just can construct the more code book of code word, and building method amount of calculation is very little.

Brief description of the drawings

Fig. 1 is the flow chart of the precoding codebook building method of a kind of mimo system of the present invention;

Fig. 2 is the composition structural representation of the precoding codebook constructing apparatus of a kind of mimo system of the present invention.

Embodiment

Below in conjunction with the drawings and specific embodiments, the technical solution of the present invention is further elaborated.

The present invention uses the long-pending or long-pending mode of similar Kronecker of Kronecker to construct the code book of 8Tx, and the flow process of the method as shown in Figure 1, comprises following steps:

Step 101, chooses the first orthogonal matrix U of N 4 × 4 _n(U ₀, U ₁... U _n-1).

Step 102, chooses N the second orthogonal matrix K _n(K ₀, K ₁... K _n-1).

Step 103, according to the U choosing _nand K _n, generate the matrix M of N 8 × 8 by the mode that Kronecker amasss or similar Kronecker is long-pending _n.

Step 104, from matrix M _nin choose the code word in the sub-codebook that row or multiple row generate each order Rank under 8 antennas.

Below the flow process shown in Fig. 1 is described in detail:

Step 101: the first orthogonal matrix U that chooses N individual 4 × 4 _n(U ₀, U ₁... U _n-1).

In this step, N≤2 ^b, wherein, B is positive integer, its implication is channel overhead bit (bit) number of feedback CSI, can set as required U _ncall number n be 0～N-1.

The first orthogonal matrix U _n(U ₀, U ₁... U _n-1) in any one can from meet the orthogonal matrix of 8PSK characteristic, orthogonal property and constant modulus property, choose, so can ensure U _nthere is 8PSK characteristic, orthogonal property and constant modulus property.The orthogonal matrix of the described 8PSK of meeting characteristic, orthogonal property and constant modulus property can be Household matrix $W_n=I-2u_n{u}_n^H/u_n^H{u}_n,$ Also can be other orthogonal matrixes that meet above-mentioned three characteristics.

$W_n=I-2u_n{u}_n^H/u_n^H{u}_n,$ Unit matrix, u that n=0～15, I are 4 × 4 _nfor vector, 16 altogether, comprise u ₀～u ₁₅; These 16 vectors are carried out to Household conversion and obtain Household matrix W _n, 16 altogether: W ₀～W ₁₅.U _ndetails as shown in table 2:

Table 2

W _nbe the sub-codebook of Rank=4 in precoding codebook under 4Tx in 3GPP LTE standard, there are a lot of good characteristics.W in the present invention _na lot of superperformances still can inherit preferably the M in step 103 _nin, as characteristics such as minimum chordal distance are large, mean chord distance is larger, and exist the characteristics such as equally distributed direction vector can pass to M under correlated channels _n.

For fixing precoding codebook, the each code word production process in code book is more similar, and all code words can be divided into two classes: the code word of the code word of coupling correlated channels and coupling non-correlation channel.For orthogonal matrix U of the present invention _n(U ₀, U ₁... U _n-1), wherein a part of matrix produces the matrix (can produce thus the code word that adapts to correlated channels) that adapts to correlated channels after step 103 expansion, part matrix produces the matrix (can produce thus the code word that adapts to non-correlation channel) that adapts to non-correlation channel after step 103 expansion, the matrix M in this two parts matrix composition step 103 _n(M ₀, M ₁... M _n-1).As can be seen here, U _n(U ₀, U ₁... U _n-1) in can comprise the orthogonal matrix that adapts to correlated channels, also can comprise the orthogonal matrix that adapts to non-correlation channel, ensured the performance of code book under correlated channels and non-correlation channel.The orthogonal matrix that wherein mates correlated channels can be from W _nw ₀～W ₇in choose; The orthogonal matrix of coupling non-correlation channel can be from W _nw ₈～W ₁₅in choose.

Suppose U _n(U ₀, U ₁... U _n-1) comprising that k adapts to the orthogonal matrix of correlated channels, k is constant (k≤N), preferably, k is N 1/2 or 1/4.According to the size order of call number, this k orthogonal matrix is arranged, be labeled as O ₁, O ₂... O _k, O _kbe 4 × 4 orthogonal matrix and adapt to correlated channels, can be from W ₀～W ₇in choose, concrete, as required, O ₁, O ₂... O _kcan adopt following method to choose:

The one, while needing direction vector to be uniformly distributed in 120 degree, O ₁, O ₂... O _kcan be from W ₀～W ₃in choose, it (is the matrix M generating after step 103 expansion that this kind of mode is applicable to available code word _n) less situation; The one, while needing direction vector to be uniformly distributed in 180 degree, O ₁, O ₂... O _kcan be from W ₄～W ₇in choose, this kind of mode is also applicable to the less situation of available code word.Above-mentioned two kinds of methods can ensure being uniformly distributed of direction vector.In addition, O ₁, O ₂... O _kcan also comprise whole W ₀～W ₇, the code word beam direction precision that this kind of mode generates is higher.

K is got to 1/2 or 1/4 of N, and this method has been considered W _nin the succession of some column vector information (comprising direction vector and vector density).The method that can describe by the present invention in step 103 is W _nfour-dimensional direction vector expand to 8 dimensions, simultaneously can also keep direction vector that larger variation can not occur, wave beam can not produce larger secondary lobe, and can avoid the power loss and the interference that cause thus.In actual application, general community be all in the directions of 120 degree or 180 degree for terminal provides service, based on method of the present invention, can ensure W _ndirection vector information can not lose, still 120 degree or 180 degree directions in be uniformly distributed.In the time of the less code book of design code number of words, can reduce W _nthe density of middle direction vector, but still need to ensure being uniformly distributed of direction vector.

By orthogonal matrix O ₁, O ₂... O _kin first row vector carry out after precoding, under correlated channels, there is good wave beam (wave beam under 4Tx) direction, after the expansion of step 103, still can keep good beam feature under 4Tx, and can form good beam direction under 8Tx; Simultaneously due to O ₁, O ₂... O _kbe to mate correlated channels, therefore can produce through the matrix that after step 103, expansion generates the code word that is applicable to correlated channels.

It is pointed out that and choose U _ntime, both can all choose the W that mates correlated channels ₀～W ₇, also can all select to get the W that mates non-correlation channel ₈～W ₁₅, also can choose the W that mates correlated channels and non-correlation channel simultaneously ₀～W ₁₅; Thus from the M of step 103 _nin the code word chosen can be all to adapt to correlated channels, or all adapt to non-correlation channel, also can comprise and adapt to correlated channels and comprise again the code word that adapts to non-correlation channel.

Step 102, chooses N the second orthogonal matrix K _n(K ₀, K ₁... K _n-1).

K in the present invention _n(K ₀, K ₁... K _n-1) can be 2 × 2 or 4 × 4 orthogonal matrix, concrete, K _nchoose and can adopt following method:

One, determine as required K _nwhile being 4 × 4 orthogonal matrix, preferably, can be from W ₀～W ₁₅in choose.Further, if while needing to generate the code word that is applicable to non-correlation channel, K ₀, K ₁... K _n-1can be from W ₈～W ₁₅in choose; If while needing to generate the code word that is applicable to correlated channels, can be from W ₀～W ₇in choose.

Due to 4 × 4 K _n(K ₀, K ₁... K _n-1) be from W _nin choose, therefore, each K _nall meet 8PSK characteristic, constant modulus property and orthogonal property.

Two, determine as required K _nwhile being 2 × 2 orthogonal matrix, K _nmatrix has following feature:

If K _nin there is no neutral element, each element of matrix is converted to after complex exponential form, the phase difference between the 1st element and the 2nd element of first row is different with the phase difference of the 2nd element from the 1st element of secondary series, this feature can be called to phase difference rule.The M that so can make step 103 generate _n(M ₀, M ₁... M _n-1) in have more column vector to mate dual polarized antenna feature and quantize the phase difference existing in dual polarized antenna horizontal polarization and vertical polarization directions.

Preferably, between the 1st element of the phase difference between the 1st of first row the element and the 2nd element and secondary series and the phase difference of the 2nd element phase difference of pi or-π.

At definite K _nwhile being 2 × 2 orthogonal matrix, preferably, can also adopt following method: K _nin with O ₁, O ₂... O _kk the orthogonal matrix that matrix is 2 × 2 of coupling.So-called K _nwith O ₁, O ₂... O _kcoupling be: determine and O _kequal U _ncall number, the K identical with this call number _nwith O _kmate, as O ₁correspond to U ₅, K ₅with O ₁mate.

Determine K _nwhile being 2 × 2 orthogonal matrix, can adopt following method to choose K _n: K _ncan from following six kinds of Mathematical Modelings, select to get:

$K_n=\left[\begin{array}{cc}{w}_1& w_1\\ w_2& -w_2\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_2& -w_2\\ w_1& w_1\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_1& w_2\\ w_1& -w_2\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_2& w_1\\ {-w}_2& w_1\end{array}\right],$

$K_n=\left[\begin{array}{cc}{w}_3& {w_4}^{*}\\ -w_4& {w_3}^{*}\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_3& {w_4}^{*}\\ w_4& -{w_3}^{*}\end{array}\right].$

Wherein w ₁, w ₂be 8PSK letter collection 1 ,-1, j ,-j, s ₀, s ₁, s ₂, s ₃in element, $s_0=(1+j)/\sqrt{2},$ $s_1=(1-j)/\sqrt{2},$ $s_2=(-1+j)/\sqrt{2},$ $s_3=-(1+j)/\sqrt{2},$ J is imaginary number; w ₃, w ₄be 4PSK letter collection 1 ,-1, j, the element in-j}.These six kinds of data model matrixes meet above-mentioned phase difference rule.

In addition, consider under some dual polarization scene, as the polarization of transmitting terminal vertical-horizontal, and receiving terminal is also vertical-horizontal polarization, from channel characteristic value exploded angle, always there is 0 element in characteristic vector, in order better to mate channel in the case, in code book, also should there is 0 element, now K _nwhile meeting following two kinds of models, there is extraordinary performance.

$K_n=\left[\begin{array}{cc}{w}_3& 0\\ 0& w_4\end{array}\right],$ $K_n=\left[\begin{array}{cc}0& w_3\\ w_4& 0\end{array}\right].$

Based on these two kinds of models, meet 8PSK characteristic by a part of element in the matrix (code word) obtaining after step 103 expansion, a part of 0 element that does not meet 8PSK characteristic does not increase the complexity of precoding in addition, and can meet constant modulus property and orthogonal property.

It is pointed out that K _nalso can from the expansion of above-mentioned eight kinds of Mathematical Modeling matrixes, select to get the expanding to of eight kinds of concrete data model matrixes: each row of matrix are multiplied by the identical or different concentrated element of 8PSK letter; Or every a line of matrix is multiplied by the identical or different concentrated element of 8PSK letter; Or the constant to Matrix Multiplication with a setting.

Due to 2 × 2 K _n(K ₀, K ₁... K _n-1) choose based on 8PSK letter collection or 4PSK letter collection, therefore can ensure 2 × 2 K _nmeet orthogonal property, 8PSK characteristic and constant modulus property.

It is pointed out that if generate coupling correlated channels code word, preferably, K _nthe matrix of middle coupling correlated channels can be all 2 × 2 matrix; If generate the code word of coupling non-correlation channel, K _nthe matrix of middle coupling non-correlation channel can comprise 2 × 2 and/or 4 × 4 matrix; In the time that the value of N is larger (preferably, a threshold value can be set as required, when N is greater than this threshold value), and while needing to generate the code word of coupling non-correlation channel, preferably, K _nthe matrix of middle coupling non-correlation channel comprises 2 × 2 and 4 × 4 matrix simultaneously.

Above-mentioned steps 101 and step 102 have been described respectively the first orthogonal matrix U _nwith the second orthogonal matrix K _nselection, it is to be noted, if contain the matrix that mates non-correlation channel in the first orthogonal matrix, the second orthogonal matrix, not only can, according to the choosing of the above-mentioned irrelevant matrix of coupling of the present invention, can also determine according to other code book design rules in prior art; In addition, in actual application, also can first select K _n, then select U _n.Work as K _nwhile being 2 × 2 matrix and need to generate the code word of correlated channels time, U _nand K _nmeet following condition: if U _e=U _f, K _e≠ K _f(e, f are less than or equal to N).

Below in conjunction with U _nillustrate K _nchoose:

An if U _e=U _f, U _e, U _fbelong to O ₁, O ₂... O _k, be to mate correlated channels, and O ₁, O ₂... O _kin there is no other matrix and U _e, U _fequate K _e≠ K _f, so can ensure the matrix M expanding _nthere is how available column vector; In addition, K _e, K _fshould distribute at space uniform, larger with the chordal distance of the matrix that ensures to expand in step 103.

Now, K _e, K _fneed further satisfied first row rule to be: if K _e, K _fdo not contain neutral element, by K _e, K _feach element convert to after complex exponential form, the 1st of each matrix is listed as between the 1st element and the 2nd element and has phase difference, and 2 of this 2 matrixes differ and in 0～2 π, be uniformly distributed.K simultaneously _e, K _falso be equally distributed in space, so K _e, K _fcan, in the dual polarized antenna scene of main flow, in correlated channels situation, there is best quantization performance.

About K _e, K _ffirst row select preferred mode:

K _e, K _fthe 1st row can be from $p*\left[\begin{array}{c}1\\ -1\end{array}\right],p*\left[\begin{array}{c}1\\ 1\end{array}\right]$ In choose;

Or K _e, K _fthe 1st row can be from $p*\left[\begin{array}{c}1\\ q3\end{array}\right],p*\left[\begin{array}{c}1\\ q1\end{array}\right]$ In choose;

Or K _e, K _fthe 1st row can be from $p*\left[\begin{array}{c}1\\ q2\end{array}\right],p*\left[\begin{array}{c}1\\ q0\end{array}\right]$ In choose;

Or K _e, K _fthe 1st row can be from $p*\left[\begin{array}{c}1\\ -j\end{array}\right],p*\left[\begin{array}{c}1\\ j\end{array}\right]$ In choose.

Wherein p is constant, can be preferably the concentrated element of 8PSK letter, wherein, and q0=s0; Q1=s2; Q2=s3; Q3=s1; It is pointed out that K _e, K _ffirst row unequal.

Based on K _e, K _fchoosing of first row, preferably,

K _e, K _fcan be from $\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right],\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right]$ In choose;

Or K _e, K _fcan be from $\left[\begin{array}{cc}1& j\\ 1& -j\end{array}\right],\left[\begin{array}{cc}1& j\\ -1& j\end{array}\right]$ In choose;

Or K _e, K _fcan be from $\left[\begin{array}{cc}1& 1\\ j& -j\end{array}\right],\left[\begin{array}{cc}1& 1\\ -j& j\end{array}\right]$ In choose;

Or K _e, K _fcan be from $\left[\begin{array}{cc}1& j\\ j& 1\end{array}\right],\left[\begin{array}{cc}1& -j\\ -j& 1\end{array}\right]$ In choose;

Or K _e, K _fcan be from $\left[\begin{array}{cc}1& 1\\ q0& q2\end{array}\right],\left[\begin{array}{cc}1& 1\\ q2& q0\end{array}\right]$ In choose;

Or K _e, K _fcan be from $\left[\begin{array}{cc}1& q3\\ q0& 1\end{array}\right],\left[\begin{array}{cc}1& q1\\ q2& 1\end{array}\right]$ In choose;

Or K _e, K _fcan be from $\left[\begin{array}{cc}1& 1\\ q1& q3\end{array}\right],\left[\begin{array}{cc}1& 1\\ q3& q1\end{array}\right]$ In choose;

Or K _e, K _fcan be from $\left[\begin{array}{cc}1& q0\\ q3& 1\end{array}\right],\left[\begin{array}{cc}1& q2\\ q1& 1\end{array}\right]$ In choose.

It is pointed out that as long as ensure K _e, K _fmeet the selection rule of above-mentioned first row and meet the first six the kind model in above-mentioned eight kinds of Mathematical Modelings, K _e, K _fcan from above-mentioned matrix, choose arbitrarily, be not limited to combination of two described above.And due to K _e, K _fselection based on be phase difference, therefore can be multiplied by a constant p for arbitrary row of above-mentioned matrix, there is the effect identical with above-mentioned matrix.

Based on above-mentioned K _e, K _fselection, except the codeword matching correlated channels that can ensure to generate, can also be applied to the generation of code word under non-correlation channel, can control preferably in step 103 matrix that generates minimum chordal distance between any two and maximize, so ensure the performance of the code word under non-correlation channel.It is to be noted while being applied to the generation of code word under non-correlation channel, or K _nwhile being 4 × 4 matrix, U _nand K _nnot necessarily meet above-mentioned: U _e=U _f, K _e≠ K _fcondition.

If two U _e=U _f=U _g=U _h, U _e, U _f, U _g, U _hbelong to O ₁, O ₂... O _k, be to mate correlated channels, and O ₁, O ₂... O _kin there is no other matrix and U _e, U _f, U _g, U _hequate K _e≠ K _f≠ K _g≠ K _h, so can ensure that the matrix expanding has how available column vector, and can ensure that the minimum chordal distance of matrix can not be 0.K in addition _e, K _f, K _g, K _hshould distribute at space uniform, larger with the matrix minimum chordal distance and the mean chord that ensure to expand in step 103.If U _e, U _f, U _g, U _hall belong to O ₁, O ₂... O _k, U _e, U _f, U _g, U _hto mate correlated channels.

Now, K _e, K _f, K _g, K _hneed further satisfied first row rule to be: by K _e, K _f, K _g, K _heach element of matrix converts to after complex exponential form, and the 1st of each matrix is listed as between the 1st element and the 2nd element and has phase difference, and 4 of this 4 matrixes differ and distribute at space uniform.The phase difference that so can ensure two polarised directions is equally distributed, by optimum quantification, under the correlated channels of dual polarized antenna scene, there is so good performance.

About K _e, K _f, K _g, K _hthe selection of first row:

K _e, K _f, K _g, K _hfirst row can be from $\left[\begin{array}{c}1\\ -1\end{array}\right],\left[\begin{array}{c}1\\ 1\end{array}\right],\left[\begin{array}{c}1\\ -j\end{array}\right],\left[\begin{array}{c}1\\ j\end{array}\right]$ In choose;

Or K _e, K _f, K _g, K _hfirst row can be from $\left[\begin{array}{c}1\\ s_0\end{array}\right],\left[\begin{array}{c}1\\ s_1\end{array}\right],\left[\begin{array}{c}1\\ s_2\end{array}\right],\left[\begin{array}{c}1\\ s_3\end{array}\right]$ In choose.

According to K _e, K _f, K _g, K _hthe 1st row phase difference need equally distributed principle, preferably, K _e, K _f, K _g, K _hthe 1st row can be from $\left[\begin{array}{c}1\\ -1\end{array}\right],\left[\begin{array}{c}1\\ 1\end{array}\right],\left[\begin{array}{c}1\\ -j\end{array}\right],\left[\begin{array}{c}1\\ j\end{array}\right]$ In choose, and K _e, K _f, K _g, K _hthe 1st row each unequal.This selection mode can better adapt to the feature of correlated channels under single-polarized antenna, some vectors in the matrix so expanding are in the correlated channels of single-polarized antenna model, the beam directional not only producing after precoding is obvious, and very even in the distribution in space.

Based on K _e, K _f, K _g, K _hchoosing of first row, preferably,

K _e, K _f, K _g, K _hfrom $\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right],\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right],\left[\begin{array}{cc}1& -1\\ j& j\end{array}\right],\left[\begin{array}{cc}1& -1\\ -j& -j\end{array}\right]$ In choose;

Or K _e, K _f, K _g, K _hfrom $\left[\begin{array}{cc}1& -1\\ 1& 1\end{array}\right],\left[\begin{array}{cc}1& -1\\ -1& -1\end{array}\right],\left[\begin{array}{cc}1& 1\\ j& -j\end{array}\right],\left[\begin{array}{cc}1& 1\\ -j& j\end{array}\right]$ In choose;

Or K _e, K _f, K _g, K _hfrom $\left[\begin{array}{cc}1& j\\ 1& -j\end{array}\right],\left[\begin{array}{cc}1& -j\\ -1& -j\end{array}\right],\left[\begin{array}{cc}1& -1\\ j& j\end{array}\right],\left[\begin{array}{cc}1& 1\\ -j& j\end{array}\right]$ In choose;

Or K _e, K _f, K _g, K _hfrom $\left[\begin{array}{cc}1& -j\\ 1& j\end{array}\right],\left[\begin{array}{cc}1& j\\ -1& j\end{array}\right],\left[\begin{array}{cc}1& 1\\ j& -j\end{array}\right],\left[\begin{array}{cc}1& -1\\ -j& -j\end{array}\right]$ In choose;

Or K _e, K _f, K _g, K _hfrom $\left[\begin{array}{cc}1& j\\ 1& -j\end{array}\right],\left[\begin{array}{cc}1& j\\ -1& j\end{array}\right],\left[\begin{array}{cc}1& 1\\ j& -j\end{array}\right],\left[\begin{array}{cc}1& 1\\ -j& j\end{array}\right]$ In choose;

Or K _e, K _f, K _g, K _hfrom $\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right],\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right],\left[\begin{array}{cc}1& 1\\ j& -j\end{array}\right],\left[\begin{array}{cc}1& 1\\ -j& j\end{array}\right]$ In choose.

It is pointed out that as long as ensure K _e, K _f, K _g, K _hmeet the selection rule of above-mentioned first row and meet above-mentioned 6 kinds of Mathematical Modelings, K _e, K _f, K _g, K _hcan from above-mentioned matrix, choose arbitrarily, be not limited to the combination of 4 matrixes described above.

Above K _e, K _f, K _g, K _hchoose being uniformly distributed most on direction vector and on dual polarized antenna phase difference of having considered this 4 matrixes, and can ensure the M generating in step 103 ₀, M ₁... M _n-1column vector in the time of single-polarized antenna, still can there is obvious directivity, and can ensure direction vector 120 degree and 180 degree directions on be uniformly distributed.Like this, the application scenarios of dual polarized antenna can be adapted to, the application scenarios of single-polarized antenna can be adapted to again.And the minimum chordal distance between these matrixes is larger, can also ensure that the code word that these matrix-expands obtain can mate non-correlation channel.The code word that it is pointed out that coupling correlated channels also can be for non-correlation channel, as long as the chordal distance of matrix is not 0.

Step 103, according to the U choosing _nand K _n, construct the matrix M of N 8 × 8 by the mode that Kronecker amasss or similar Kronecker is long-pending _nmatrix M _n.

Based on the U selecting in above-mentioned steps _n, K _nif, K _nbe 2 × 2 matrixes, use the long-pending mode of Kronecker: or the M of structure 8 × 8 _n(M ₀, M ₁... M _n-1); If K _nbe 4 × 4 matrixes, use the long-pending mode of similar Kronecker $\left[\begin{array}{cc}{a}_n{U}_n& c_n{K}_n\\ b_n{U}_n& d_n{K}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{K}_n& c_n{U}_n\\ b_n{K}_n& d_n{U}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{K}_n& c_n{K}_n\\ b_n{U}_n& d_n{U}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{U}_n& c_n{U}_n\\ b_n{K}_n& d_n{K}_n\end{array}\right]$ The M of structure 8 × 8 _n(M ₀, M ₁... M _n-1).Wherein, $\left(\begin{array}{cc}{a}_n& c_n\\ b_n& d_n\end{array}\right)$ For orthogonal matrix, a _n, b _n, c _n, d _nit can be the concentrated element of 8PSK letter.

If $A_n=\left(\begin{array}{cc}{a}_n& c_n\\ b_n& d_n\end{array}\right),$ A _ncan be from K _nthe first six plant in model and choose arbitrarily.

Same, consider under some dual polarization scene, as the polarization of transmitting terminal vertical-horizontal, and receiving terminal is also vertical-horizontal polarization, from channel characteristic value exploded angle, always there is 0 element in characteristic vector, in order better to mate channel in the case, also should have 0 element in code book.Now, a _n, b _n, c _n, d _nin can promising 0 element, a _n, d _nbe 0 simultaneously, or b _n, c _nbe 0 simultaneously, but a _n, b _n, c _n, d _nwhen different, be 0, now A _ncan be from K _nlatter two model in choose arbitrarily.

A _n, d _nbe 0 simultaneously, or b _n, c _nbe 0 o'clock simultaneously, consequent 8 × 8 matrix M _nmiddle a part of element meets 8PSK characteristic, and a part of 0 element that does not meet 8PSK characteristic does not increase the complexity of precoding in addition, and can meet constant modulus property and orthogonal property.

It is pointed out that A _nalso can from the expansion of above-mentioned eight kinds of models, choose the same K of expansion of eight kinds of concrete models _nthe expansion of eight kinds of models, repeat no more herein.

Step 104: from M _nmiddle extraction one is listed as or multiple row forms the part code word in the sub-codebook of each Rank under 8Tx.

Preferably, from M _nwhen middle extraction one is listed as or multiple row forms the part code word in the sub-codebook of each Rank, need to meet Nested property, can reduce like this memory space, reduce CQI (CQI, ChannelQuality Indicator) amount of calculation and support Rank adaptive change.Other code words in the sub-codebook of Rank can be determined according to code book method for designing of the prior art.

So-called Nested property refers to, for the code word of the same call number under different Rank, low-rank code word forms by extracting several row in high order code word.Nested property can make to receive and dispatch sending end memory space and reduce, and in actual application, Rank often automatically changes, and meets self adaptation that Nested property can make Rank and becomes and be more prone to, and can reduce the complexity that CQI calculates; In addition, at UE end, as long as the code book of its storage obtains the code book that the highest Rank is corresponding, the situation of other Rank only need to be extracted in code book corresponding to the highest Rank, has so saved the storage overhead of UE.

Below by specific embodiment, the solution of the present invention is described:

Embodiment 1, determines N=16 as required.

1, U _nchoose.

If the matrix of the coupling correlated channels that need to obtain is M _nin first 8, i.e. M ₀, M ₁... M ₇, can determine M ₀, M ₁... M ₇by O ₁, O ₂... O _kproduce, preferably, k=8, O ₁, O ₂... O _kcan be U ₀, U ₁... U ₇; Suppose U ₈, U ₉... U ₁₅for the matrix of coupling non-correlation channel, can adopt the choosing method that mates non-correlation channel matrix in the first orthogonal matrix of the present invention, also can adopt other code book design rules in prior art to determine.It is pointed out that O ₁, O ₂... O _kcorresponding U _nalso can be discontinuous (call number is discontinuous).Embodiments of the invention are with O ₁, O ₂... O _ku ₀, U ₁... U ₇for example.

O ₁, O ₂... O _k(U ₀, U ₁... U ₇) in matrix be coupling correlated channels, be from W ₀, W ₁... W ₇in choose, different O _kcan select identical W _n.If current available code word number is less, and need in the phase difference dimension of dual polarized antenna, quantize meticulouslyr, in direction dimension, should use less direction vector, further, need to ensure that direction vector is uniformly distributed in 120 degree directions time, O ₁, O ₂... O _kcan be all from W ₀, W ₁... W ₃in choose; Need to ensure that direction vector is uniformly distributed in 180 degree directions time, O ₁, O ₂... O _kcan be all from W ₄, W ₅... W ₇in choose.Hence one can see that, W ₀, W ₁... W ₃or W ₄, W ₅... W ₇in each matrix at O ₁, O ₂... O _kin have 2 matrixes with it equate.So can ensure that beam direction is uniformly in 120 degree or 180 degree, and in each direction, have 2 identical basis matrixs.

Preferably, U _nchoosing as shown in Table 3 and Table 4 of the matrix of middle coupling correlated channels:

Table 3

Table 4

Preferably, U _nchoosing of the matrix of middle coupling non-correlation channel is as shown in table 5:

Table 5

2, K _nchoose.

Suppose U ₀, U ₁... U ₇middle U ₀=U ₁, U ₂=U ₃, U ₄=U ₅, U ₆=U ₇, can determine K ₀≠ K ₁, K ₂≠ K ₃, K ₄≠ K ₅, K ₆≠ K ₇; Preferably, according to the K describing in step 102 _nselection rule, K ₀～K ₇choose as shown in table 6:

Table 6

Preferably, K ₈～K ₁₅choose as shown in table 7:

Table 7

So can protect N the minimum chordal distance between code word larger with average chordal distance, better performances under non-correlation channel.

3, generate M _n.

If K _nbe 2 × 2 matrix, and choose ?

$M_0=K_0\⊗U_0=\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right]\⊗W_0;$ $M_1=K_1\⊗U_1=\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right]\⊗W_0;$

$M_2=K_2\⊗U_2=\left[\begin{array}{cc}1& j\\ 1& -j\end{array}\right]\⊗W_1;$ $M_3=K_3\⊗U_3=\left[\begin{array}{cc}1& j\\ -1& j\end{array}\right]\⊗W_1$

$M_{N-1}=K_{N-1}\⊗U_{N-1}=\left[\begin{array}{cc}1& j\\ -1& j\end{array}\right]\⊗W_{N-1}.$

4, generated codeword.

From M _nin choose row or multiple row forms the part code word under each Rank:

From M ₀, M ₁... M _n-1in choose the 1st row as the part code word of Rank=1

From M ₀, M ₁... M _n-1in choose the 1st, 5 row as the part code words of Rank=2

From M ₀, M ₁... M _n-1in choose the 1st, 2,5 row as the part code words of Rank=3

From M ₀, M ₁... M _n-1in choose the the 1st, 2,5,6 row as the part code words of Rank=4

From M ₀, M ₁... M _n-1in choose the the the 1st, 2,3,5,6 row as the part code words of Rank=5

From M ₀, M ₁... M _n-1in choose the the the 1st, 2,3,5,6,7 row as the part code words of Rank=6

From M ₀, M ₁... M _n-1in choose the the the the 1st, 2,3,4,5,6,7 row as the part code words of Rank=7

From M ₀, M ₁... M _n-1in choose the the the the the 1st, 2,3,4,5,6,7,8 row as the part code words of Rank=8.

The code word of above-mentioned generation meets Nested property.The part code word that it is pointed out that Rank=1 need to be chosen M ₀, M ₁... M _n-1the 1st row form; The part code word of Rank=2 needs M ₀, M ₁... M _n-1the 1st, 5 row form; Choosing as required of Rank=3,4,5,6,7,8 part code word determined, is not limited to cited the choosing of this embodiment.

Embodiment 2, determines N=32 as required.

1, U _nchoose.

If the matrix of the coupling correlated channels that need to obtain is M _nin first 16, i.e. M ₀, M ₁... M ₁₅, can determine M ₀, M ₁... M ₁₅by O ₁, O ₂... O _kproduce, preferably, k=16, O ₁, O ₂... O _kcan be U ₀, U ₁... U ₁₅; Suppose U ₁₆, U ₁₇... U ₃₁for the matrix of coupling non-correlation channel, can adopt the choosing method that mates non-correlation channel matrix in the first orthogonal matrix of the present invention, also can adopt other code book design rules in prior art to determine.It is pointed out that O ₁, O ₂... O _kcorresponding U _nalso can be discontinuous (call number is discontinuous).

O ₁, O ₂... O _k(U ₀, U ₁... U ₁₅) in matrix be coupling correlated channels, be from W ₀, W ₁... W ₇in choose, different O _kcan select identical W _n.If think that current available code word number is less, and need in the phase difference dimension of dual polarized antenna, quantize meticulouslyr, in direction dimension, should use less direction vector, further, need to ensure that direction vector is uniformly distributed in 120 degree directions time, O ₁, O ₂... O _kcan be all from W ₀, W ₁... W ₃in choose; Need to ensure that direction vector is uniformly distributed in 180 degree directions time, O ₁, O ₂... O _kcan be all from W ₄, W ₅... W ₇in choose.Hence one can see that, W ₀, W ₁... W ₃or W ₄, W ₅... W ₇in each matrix at O ₁, O ₂... O _kin have 4 matrixes with it equate.So can ensure that beam direction is uniformly in 120 degree or 180 degree, and in each direction, have 4 identical basis matrixs.

Preferably, U _nthe matrix U of middle coupling correlated channels ₀～U ₁₅choose as shown in table 8 table 9: establish m=0～3

Table 8

Table 9

Preferably, U _nthe matrix U of middle coupling non-correlation channel ₁₆～U ₃₁choose as shown in table 10: establish m=8～15

Table 10

2, K _nchoose.

Suppose U ₀, U ₁... U ₁₅middle U _4m=U _4m+1=U _4m+2=U _4m+3, can determine K _4m≠ K _4m+1≠ K _4m+2≠ K _4m+3, m=0～3; Preferably, according to the K describing in step 102 _nselection rule, K ₀～K ₁₅choose as shown in table 11:

Table 11

K ₁₆～K ₃₁the matrix that mates non-correlation channel in can be according to the present invention in the second orthogonal matrix of determining choose, also can determine according to other code book method for designing in prior art.

3, generate M _n.

If K _nbe 2 × 2 matrix, and choose ?

$M_0=U_0\⊗K_0=W_0\⊗\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right];$ $M_1=U_1\⊗K_1=W_0\⊗\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right];$

$M_2=U_2\⊗K_2=W_1\⊗\left[\begin{array}{cc}1& j\\ 1& -j\end{array}\right];$ $M_3=U_3\⊗K_3=W_1\⊗\left[\begin{array}{cc}1& j\\ -1& j\end{array}\right]$

$M_{N-1}=U_{N-1}\⊗K_{N-1}=W_{N-1}\⊗\left[\begin{array}{cc}1& j\\ -1& j\end{array}\right].$

4, generated codeword.

Can adopt the code word of embodiment 1 to form, repeat no more herein.

Embodiment 3, determines N=16 or 32 as required.

If wherein mating the matrix of correlated channels is M _nin whole 16 (N=16), or front 16 (N=32) are M ₀, M ₁... M ₁₅, k=16, M ₀, M ₁... M ₁₅by O ₁, O ₂... O _kproduce namely U ₀, U ₁... U ₁₅, other U value is to determine by other code book methods for designing in prior art.Certainly, if the matrix of coupling correlated channels is not regular like this distribution, O ₁, O ₂... O _kat U _ndistribution can be also discontinuous.

O ₁, O ₂... O _k(U ₀, U ₁... U ₇) in matrix be from W ₀, W ₁... W ₇in choose, different O _kcan select identical W _n.In order to ensure being uniformly distributed in 120 degree or 180 degree directions, W ₀, W ₁... W ₇in each matrix at O ₁, O ₂... O _kin have 2 matrixes with it equate.

Preferably, U ₀～U ₁₅selection as shown in table 12: m=0～7

Table 12

Preferably, U ₁₆～U ₃₁selection as shown in table 13: m=8～15

Table 13

Preferably, K _nselection as:

Wherein K _2m≠ K _2m+1, m=0,1,2,3......7

Certainly, also can select

Or

Or

It is pointed out that K herein _2mand K _2m+1selection be not limited to all will from above-mentioned same group of matrix, choose, in the time of m=r, also can choose:

When m=1, also can choose:

M _ngeneration identical with previously described embodiment 1, repeat no more herein.

From M _nin choose row or multiple row forms the part code word under each Rank: (following this mode is the identical example of selection rule of code word corresponding to different call number (Index))

From M ₀in to choose the 1st row be 0 as the Index in Rank=1 part code word;

From M ₁in to choose the 2nd row be 1 as the Index in Rank=1 part code word;

From M _n-1in to choose the 8th row be N-1 as the Index in Rank=1 part code word;

Or,

From M ₀in to choose the 1st, 5 row be 0 as the Index in Rank=2 part code word;

From M ₁in to choose the 5th, 1 row be 1 as the Index in Rank=2 part code word;

From M _n-1in to choose the 2nd, 6 row be N-1 as the Index in Rank=2 part code word;

Or

From M ₀in to choose the 1st, 2,5 row be 0 as the Index in Rank=2 part code word;

From M ₁in to choose the 5th, 1,6 row be 1 as the Index in Rank=2 part code word;

From M _n-1in to choose the 5th, 2,6 row be N-1 as the Index in Rank=2 part code word;

Or,

Other Rank also similarly, keeps Nested property for the code word of the different Rank under each Index.

Embodiment 4, determines N=16 or 32 as required.

If the matrix of coupling correlated channels is M ₀, M ₁... M _n-1in whole 16 (N=16), or front 16 (N=32) are M ₀, M ₁... M ₁₅, determine k=16.

Can first provide K _nselection as:

Wherein K _2m≠ K _2m+1, m=0～7.

Provide again corresponding U _nselection, U ₀～U ₁₅selection: m=0～7

Table 14

The in the situation that of N=32, U ₁₆～U ₃₁selection: m=8～15

Table 15

M _ngeneration identical with previously described embodiment, repeat no more herein.

From M _nin choose row or multiple row forms the part code word under each Rank: identical with the selection of embodiment 2 herein, repeat no more.

Embodiment 5, determines N=16 or 32 as required.

If the matrix of coupling correlated channels is M ₀, M ₁... M _n-1in whole 16 (N=16), or front 16 (N=32) are M ₀, M ₁... M ₁₅, determine k=16.

Preferably, U ₀～U ₁₅selection: m=0～7

Table 16

If, there is U in N=32 ₁₆～U ₃₁, preferably, U ₁₆～U ₃₁can select: m=8～15

Table 17

Preferably, K _n(K ₀～K ₁₅) selection as follows:

Table 18

Wherein K _2m≠ K _2m+1, m=0,1,2,3......7

K ₁₆～K ₃₁meet 8PSK characteristic, orthogonal property and constant modulus property; Wherein K _2m≠ K _2m+1, m=8～15.

M _ngeneration identical with previously described embodiment, repeat no more herein.

From M _nin choose row or multiple row forms the part code word under each Rank: identical with the selection of embodiment 2 herein, repeat no more.

Embodiment 6, determines N=16 or 32 as required.

If the matrix of coupling correlated channels is M ₀, M ₁... M _n-1in whole 16 (N=16), or front 16 (N=32) are M ₀, M ₁... M ₁₅, determine k=16.

Preferably, U ₀～U ₁₅selection: m=0～7

Table 19

If, there is U in N=32 ₁₆～U ₃₁, preferably, U ₁₆～U ₃₁can select: m=8～15

Table 20

Preferably, K _n(K ₀～K ₁₅) selection as:

Table 21

Wherein, K _2m≠ K _2m+1, m=0,1,2,3......7

K ₁₆～K ₃₁meet 8PSK characteristic, orthogonal property and constant modulus property; Wherein K _2m≠ K _2m+1, m=8～15.

K _nwhile being 2 × 2 matrix, M _ngeneration can mix selection $M_n=K_n\⊗U_n$ Or $M_n=U_n\⊗K_n:$

$M_m=K_m\⊗U_m,$ m＝0，1，2，…15：

$M_0=K_0\⊗U_0=\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right]\⊗W_0$

$M_1=K_1\⊗U_1=\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right]\⊗W_0$

$M_2=K_2\⊗U_2=\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right]\⊗W_1$

$M_3=K_3\⊗U_3=\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right]\⊗W_1$

$M_l=U_l\⊗K_l,$ l＝16，17，18，…31

$M_{16}=U_{16}\⊗K_{16}=W_8\⊗\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right]$

$M_{17}=U_{17}\⊗K_{17}=W_8\⊗\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right]$

$M_{18}=U_{18}\⊗K_{18}=W_9\⊗\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right]$

$M_{19}=U_{19}\⊗K_{19}=W_{19}\⊗\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right]$

From M _nin choose row or multiple row forms the part code word under each Rank: identical with the selection of embodiment 2 herein, repeat no more.

Embodiment 7, determines N=16 or 32 as required.

U _nand K _nselection with embodiment 6, repeat no more herein.

K _nboth comprised 4 × 4 matrix, also comprised at 2 × 2 o'clock, M _nstructure can choose: or or $\left[\begin{array}{cc}{a}_n{U}_n& c_n{K}_n\\ b_n{U}_n& d_n{K}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{K}_n& c_n{U}_n\\ b_n{K}_n& d_n{U}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{K}_n& c_n{K}_n\\ b_n{U}_n& d_n{U}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{U}_n& c_n{U}_n\\ b_n{K}_n& d_n{K}_n\end{array}\right].$ Concrete as:

$M_m=K_m\⊗U_m,$ m＝0，1，2，…15

$M_0=K_0\⊗U_0=\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right]\⊗W_0$

$M_1=K_1\⊗U_1=\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right]\⊗W_0$

$M_2=K_2\⊗U_2=\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right]\⊗W_1$

$M_{15}=K_{15}\⊗U_{15}=\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right]\⊗W_7$

M ₁₆～M ₃₁generation can be:

$M_{16}=\left[\begin{array}{cc}{a}_{16}{U}_{16}& c_{16}{K}_{16}\\ b_{16}{U}_{16}& d_{16}{K}_{16}\end{array}\right]$

$M_{17}=\left[\begin{array}{cc}{a}_{17}{K}_{17}& c_{17}{U}_{17}\\ b_{17}{K}_{17}& d_{17}{U}_{17}\end{array}\right]$

$M_{18}=\left[\begin{array}{cc}{a}_{18}{K}_{18}& c_{18}{U}_{18}\\ b_{18}{U}_{18}& d_{18}{K}_{18}\end{array}\right]$

$M_{19}=\left[\begin{array}{cc}{a}_{19}{U}_{19}& c_{19}{K}_{19}\\ b_{19}{K}_{19}& d_{19}{U}_{19}\end{array}\right]$

$M_{20}=W_{10}\⊗K_{20}$

From M _nin choose row or multiple row forms the part code word under each Rank: identical with the selection of embodiment 2 herein, repeat no more.

Embodiment 8, determines N=16 or 32 as required.

If the matrix of coupling correlated channels is M ₀, M ₁... M _n-1in first 16, M ₀, M ₁... M ₁₅, determine k=16; M ₀, M ₁... M ₁₅by corresponding O ₁, O ₂... O _kproduce namely U ₀, U ₁... U ₁₅if N=16, has not had other U value; If N=32, other U value is coupling non-correlation channel, can determine by other code book method for designing in prior art, also can choose by method of the present invention.

O ₁, O ₂... O _k(U ₀, U ₁... U ₇) in matrix from W ₀, W ₁... W ₇in choose, need to ensure that direction vector is uniformly distributed in 120 degree directions time, O ₁, O ₂... O _kcan be all from W ₀, W ₁... W ₃in choose; Need to ensure that direction vector is uniformly distributed in 180 degree directions time, O ₁, O ₂... O _kcan be all from W ₄, W ₅... W ₇in choose.Hence one can see that, W ₀, W ₁... W ₃or W ₄, W ₅... W ₇in each matrix at O ₁, O ₂... O _kin have 2 matrixes with it equate.So can ensure that beam direction is uniformly in 120 degree or 180 degree, and in each direction, have 2 identical basis matrixs.

Preferably, U _nchoosing of the matrix of middle coupling correlated channels is as follows:

Table 25

U _nin other matrixes select time, need to meet 8PSK characteristic.

Preferably, K _nthe selection of (n=0～15)

Table 26

Wherein [a _nb _n] ^twith K _nfirst row orthogonal, and a _n, b _nall concentrated element n=0～15 of 8PSK letter.

M _ngeneration identical with embodiment 2, repeat no more herein.

From M _nin choose row or multiple row forms the part code word under each Rank: identical with the selection of embodiment 2 herein, repeat no more.

For U _nand K _nchoose, this embodiment is that one is preferably selected.

Embodiment 9, determines N=16 or 32 as required.

If the matrix of coupling non-correlation channel is M ₀, M ₁... M _n-1in first 16, coupling correlated channels matrix be M ₀, M ₁... M _n-1in other 16; Or coupling non-correlation channel is 16 whole matrixes.Mate the U of non-correlation channel _nfrom W ₈, W ₉... W ₁₅in choose, as follows:

Table 27

Preferably, K _nthe selection of (n=0～15) is as follows:

Table 28

M _ngeneration identical with embodiment 2, repeat no more herein.

From M _nin choose row or multiple row forms the part code word under each Rank: identical with the selection of embodiment 2 herein, repeat no more.

Embodiment 10, determines N=16 as required.

If wherein mating the matrix of correlated channels is M ₀, M ₁... M _n-1in first 8, coupling non-correlation channel matrix be M ₀, M ₁... M _n-1in other 8.Mate the U of non-correlation channel _nfrom W ₈, W ₉... W ₁₅in choose, as follows:

Table 29

The U that it is pointed out that coupling non-correlation channel is not necessarily corresponding is exactly U ₀～U ₇, concrete determines as required.

Suppose K herein _nbe 4 × 4 matrix, K _nchoose as follows:

Table 30

This method can make minimum chordal distance and on average chordal distance is very even, has good performance under non-correlation channel.

Generate M _ntime, can select $M_n=\left[\begin{array}{cc}{a}_n{U}_n& c_n{K}_n\\ b_n{U}_n& d_n{K}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{K}_n& c_n{U}_n\\ b_n{K}_n& d_n{U}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{K}_n& c_n{K}_n\\ b_n{U}_n& d_n{U}_n\end{array}\right],$ Or $\left[\begin{array}{cc}{a}_n{U}_n& c_n{U}_n\\ b_n{K}_n& d_n{K}_n\end{array}\right]$ In one or more.

From M _nin choose row or multiple row forms the part code word under each Rank: identical with the selection of embodiment 2 herein, repeat no more.

Embodiment 11, determines N=32 as required.

1, U _nchoose.

If the matrix of the coupling correlated channels that need to obtain is M _nin first 8, i.e. M ₀, M ₁... M ₇, can determine M ₀, M ₁... M ₇by O ₁, O ₂... O _kproduce, preferably, k=8, O ₁, O ₂... O _kcan be U ₀, U ₁... U ₇; U ₈, U ₉... U ₃₁for the matrix of coupling non-correlation channel, can adopt the choosing method that mates non-correlation channel matrix in the first orthogonal matrix of the present invention, also can adopt other code book design rules in prior art to determine.It is pointed out that O ₁, O ₂... O _kcorresponding U _nalso can be discontinuous (call number is discontinuous).

O ₁, O ₂... O _k(U ₀, U ₁... U ₇) in matrix be coupling correlated channels, be from W ₀, W ₁... W ₇in choose

Preferably, the matrix U of coupling correlated channels ₀, U ₁... U ₇be chosen for: $U_n=W_m=I-2u_m{u}_m^H/u_m^H{u}_m,$ Wherein, m=0～7.

2, K _nchoose.

Preferably, according to the K describing in step 102 _nselection rule, the performance being increased under some scene of dual polarized antenna is considered, K ₀～K ₇can from following four kinds of matrixes, choose arbitrarily:

$\left[\begin{array}{cc}1& 0\\ 0& 1\end{array}\right],$ Or $\left[\begin{array}{cc}0& 1\\ 1& 0\end{array}\right],$ Or $\left[\begin{array}{cc}1& 1\\ j& -j\end{array}\right],$ Or $\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right].$

K ₈, K ₉... K ₃₁the matrix that mates non-correlation channel in can be according to the present invention in the second orthogonal matrix of determining choose, also can determine according to other code book method for designing in prior art.

3, generate M _n.

If K _nbe 2 × 2 matrix, and choose ?

$M_0=U_0\⊗K_0=W_0\⊗\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right];$ $M_1=U_1\⊗K_1=W_0\⊗\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right];$

$M_2=U_2\⊗K_2=W_1\⊗\left[\begin{array}{cc}1& j\\ 1& -j\end{array}\right];$ $M_3=U_3\⊗K_3=W_1\⊗\left[\begin{array}{cc}1& j\\ -1& j\end{array}\right];$

$M_{N-1}=U_{N-1}\⊗K_{N-1}=W_{N-1}\⊗\left[\begin{array}{cc}1& j\\ -1& j\end{array}\right].$

Also can adopt otherwise, as $M_n=K_n\⊗U_n.$

4, generated codeword.

Can adopt the code word of embodiment 1 to form, repeat no more herein.

For realizing the precoding codebook building method of above-mentioned multi-input multi-output system, the present invention also provides a kind of precoding codebook device of multi-input multi-output system, as shown in Figure 2, comprising: matrix is chosen module 10, matrix generation module 20 and code book generation module 30, wherein

Matrix is chosen module 10, for choosing the first orthogonal matrix U of N individual 4 × 4 _n, and N the second orthogonal matrix K _n, and by the U choosing _nand K _noffer matrix generation module;

Matrix generation module 20, the U choosing for basis _nand K _n, generate the matrix M of N 8 × 8 by the mode that Kronecker amasss or similar Kronecker is long-pending _n;

Code book generation module 30, for from matrix M _nin choose the part code word in the sub-codebook that 1 row or multiple row generate each Rank under 8 antennas.

Matrix is chosen module 10 and is further used for, from orthogonal matrix W _nin choose N U _n, and $W_n=I-2u_n{u}_n^H/u_n^H{u}_n,$ U _nfor vector, comprise u ₀u ₁₅.

K _nwhile being 4 × 4 matrix, matrix is chosen module 10 and is further used for, from W _nw ₀～W ₁₅in choose K _n.

K _nwhile being 2 × 2 matrix, matrix is chosen module 10 and is further used for, and from following eight kinds of Mathematical Modeling matrixes, chooses K _n:

$K_n=\left[\begin{array}{cc}{w}_1& w_1\\ w_2& {-w}_2\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_2& -w_2\\ w_1& w_1\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_1& w_2\\ w_1& -w_2\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_2& w_1\\ {-w}_2& w_1\end{array}\right],$

$K_n=\left[\begin{array}{cc}{w}_3& {w_4}^{*}\\ -w_4& {w_3}^{*}\end{array}\right],$ $K_n=\left[\begin{array}{cc}{w}_3& {w_4}^{*}\\ w_4& {{-w}_3}^{*}\end{array}\right];$ $K_n=\left[\begin{array}{cc}{w}_3& 0\\ 0& w_4\end{array}\right],$ $K_n=\left[\begin{array}{cc}0& w_3\\ w_4& 0\end{array}\right].$

Wherein, w ₁, w ₂for 8PSK letter collection $\{1,-1,j,-j,\frac{1+j}{\sqrt{2}},\frac{-1+j}{\sqrt{2}},\frac{1-j}{\sqrt{2}},\frac{-1-j}{\sqrt{2}}\}$ In element, w ₃, w ₄collect for 4PSK is alphabetical 1 ,-1, j, the element in-j}.

The above, be only preferred embodiment of the present invention, is not intended to limit protection scope of the present invention.

Claims (11)

1. a precoding codebook building method for multi-input multi-output system, is characterized in that, the method comprises:

From orthogonal matrix W _nin choose the first orthogonal matrix U of N 4 × 4 _n, and choose N the second orthogonal matrix K _n; Described N≤2 ^b, B is the channel overhead bit number of feedback channel information CSI, is positive integer; Described u _nfor vector, n=0～15; Described W _nmeet 8 phase shift keying PSK characteristics, constant modulus property and orthogonal property;

According to the U choosing _nand K _n, construct the matrix M of N 8 × 8 by the mode that Kronecker amasss or similar Kronecker is long-pending _n;

From matrix M _nin choose the part code word in the sub-codebook that row or multiple row generate each order Rank under 8 antennas.

2. the precoding codebook building method of multi-input multi-output system according to claim 1, is characterized in that, the method further comprises: a described N U _nin comprise k and adapt to the orthogonal matrix of correlated channels, be arranged as O by the size order of call number n ₁, O ₂o _k, and O ₁, O ₂o _kfrom described W _nw ₀～W ₇in choose, k≤N.

3. the precoding codebook building method of multi-input multi-output system according to claim 2, is characterized in that described O ₁, O ₂o _kfrom W ₀～W ₇in choose, be specially:

While needing direction vector to be uniformly distributed in 120 degree, O ₁, O ₂o _kfrom W ₀～W ₃in choose;

Or, while needing direction vector to be uniformly distributed in 180 degree, O ₁, O ₂o _kfrom W ₄～W ₇in choose;

Or, O ₁, O ₂o _kcomprise W ₀～W ₇;

Described direction vector is O ₁, O ₂o _kthe direction vector that middle first row forms.

4. the precoding codebook building method of multi-input multi-output system according to claim 1, is characterized in that a described N K _nbe 2 × 2 orthogonal matrix, or 4 × 4 orthogonal matrix;

K _nwhile being 2 × 2 orthogonal matrix, the corresponding long-pending mode of Kronecker is specially: or

K _nwhile being 4 × 4 orthogonal matrix, the corresponding long-pending mode of similar Kronecker is specially: or or or described for orthogonal matrix, a _n, b _n, c _n, d _nfor 8PSK letter collection in element, or a _n, d _nbe 0 simultaneously, or b _n, c _nbe 0 simultaneously.

5. the precoding codebook building method of multi-input multi-output system according to claim 4, is characterized in that, when the value of described N is greater than default threshold value, and K _nthe matrix of middle coupling non-correlation channel had both comprised 2 × 2 orthogonal matrix, also comprised 4 × 4 orthogonal matrix.

6. according to the precoding codebook building method of multi-input multi-output system described in claim 4 or 5, it is characterized in that, if K _nbe 4 × 4 orthogonal matrix, K _nfrom W ₀～W ₁₅in choose, concrete:

If need to generate the code word that is applicable to correlated channels, K _nfrom W ₀～W ₇in choose;

If need to generate the code word that is applicable to non-correlation channel, K _nfrom W ₈～W ₁₅in choose.

7. according to the precoding codebook building method of multi-input multi-output system described in claim 4 or 5, it is characterized in that described K _nwhile being 2 × 2 orthogonal matrix, the method further comprises: described 2 × 2 orthogonal matrix is chosen from following eight kinds of Mathematical Modeling matrixes:

Wherein, w ₁, w ₂for 8PSK letter collection in element, w ₃, w ₄collect for 4PSK is alphabetical 1 ,-1, j, the element in-j}.

8. the precoding codebook building method of multi-input multi-output system according to claim 7, is characterized in that, the method further comprises: described 2 × 2 orthogonal matrix is chosen from the expansion of described eight kinds of Mathematical Modeling matrixes;

The expansion of described eight kinds of Mathematical Modelings, is specially: each row of described matrix are multiplied by the identical or different concentrated element of 8PSK letter; Or every a line of described matrix is multiplied by the identical or different concentrated element of 8PSK letter; Or by described Matrix Multiplication with a constant.

9. the precoding codebook building method of multi-input multi-output system according to claim 1, is characterized in that, when code word under described generation 8 antennas in the sub-codebook of each order Rank, the method further comprises: according to Nested property, from matrix M _nin choose the part code word in the sub-codebook that row or multiple row generate each order Rank under 8 antennas.

10. a precoding codebook constructing apparatus for multi-input multi-output system, is characterized in that, this device comprises: matrix is chosen module, matrix generation module and code book generation module, wherein,

Described matrix is chosen module, for from orthogonal matrix W _nin choose the first orthogonal matrix U of N 4 × 4 _n, and N the second orthogonal matrix K _n, and by the U choosing _nand K _noffer described matrix generation module; Described N≤2 ^b, B is the channel overhead bit number of feedback channel information CSI, is positive integer; Described u _nfor vector, n=0～15; Described W _nmeet 8 phase shift keying PSK characteristics, constant modulus property and orthogonal property;

Described matrix generation module, the U choosing for basis _nand K _n, generate the matrix M of N 8 × 8 by the mode that Kronecker amasss or similar Kronecker is long-pending _n;

Described code book generation module, for from matrix M _nin choose the code word in the sub-codebook that 1 row or multiple row generate each Rank under 8 antennas.

The 11. precoding codebook constructing apparatus of multi-input multi-output system according to claim 10, is characterized in that,

Described K _nwhile being 4 × 4 matrix, matrix is chosen module and is further used for, from W _nw ₀～W ₁₅in choose K _n;

Described K _nwhile being 2 × 2 matrix, matrix is chosen module and is further used for, and from following eight kinds of Mathematical Modeling matrixes, chooses K _n:

Wherein, w ₁, w ₂for 8PSK letter collection in element, w ₃, w ₄collect for 4PSK is alphabetical 1 ,-1, j, the element in-j}.