CN101931512B - A kind of acquisition methods of channel information and device - Google Patents

Abstract

The invention discloses a kind of acquisition methods and device of channel information, to solve the technical problem that code book of the prior art can not support the feedback of multiple precision.Wherein the method comprises: for a subband, and the RI information of channel and at least one PMI information are fed back to base station by terminal; Wherein this PMI information comprises PMI1 information; This base station finds call number to be the code word W 1 of PMI1 according to this RI information and this PMI1 information from 4 antenna codebooks; Or this base station is according to this RI information and this PMI1 information, from 8 antenna codebooks, a call number is found to be the code word W 1 of PMI1; This base station obtains the channel information of this subband according to this code word W 1, matrix W 2 and function F (W1, W2).Channel information acquisition technology provided by the invention, can provide multiple accuracy modes, can be applied to the feedback of channel information neatly, efficiently utilize feedback overhead.

Description

Channel information acquisition method and device

Technical Field

The present invention relates to the field of communications, and in particular, to a method and an apparatus for acquiring channel information.

Background

In a wireless communication system, a transmitting end and a receiving end adopt a spatial multiplexing mode to use a plurality of antennas to obtain higher speed. Compared with a general spatial multiplexing method, an enhanced technology is that a receiving end feeds back channel information to a sending end, and the sending end uses a transmitting pre-coding technology according to the obtained channel information, so that the transmission performance can be greatly improved. For single-user multiple-input multiple-output (SU-MIMO, where MIMO denotes Multi-input Multi-output, multiple-input multiple-output), precoding is performed directly using channel feature vector information; for multi-user MIMO (MU-MIMO), relatively accurate channel information is required.

In the third generation partnership project (3GPP) Long Term Evolution (LTE) project, feedback of channel information mainly uses a simpler feedback method of a single codebook, and the performance of the MIMO transmission precoding technology depends more on the accuracy of codebook feedback therein.

The basic principle of codebook-based quantization feedback of channel information is briefly described as follows:

assuming that the limited feedback channel capacity is bps/Hz, the number of available codewords is N-2^BAnd (4) respectively. The eigenvector space of the channel matrix is quantized to form codebook space R ═ { F ═ F₁，F₂…F_N}. The transmitting end and the receiving end jointly store or generate the codebook R in real time (the transmitting end and the receiving end are the same). For each channel realization H, the receiving end selects a code word F which is most matched with the channel realization H from the codebook space R according to a certain criterion, and feeds back the serial number i (code word serial number) of the code word F to the transmitting end. Here, the codeword number is referred to as a codebook Precoding Matrix Indicator (PMI for short). The transmitting end finds out the corresponding precoding code word F according to the sequence number i, so that corresponding channel information is obtained, wherein F represents the characteristic vector information of the channel.

Generally, the codebook space R may be further divided into a plurality of codebooks corresponding to the ranks, and each Rank may correspond to a plurality of code words to quantize a precoding matrix formed by the channel feature vectors in the Rank. Since the number of Rank and non-zero eigenvector of a channel is equal, in general, a codeword has N columns when Rank is N. Therefore, the codebook space R can be divided into a plurality of sub-codebooks according to the Rank, as shown in table 1.

TABLE 1 codebook divided into multiple sub-codebooks by Rank schematic

When Rank is greater than 1, the code words required to be stored are all in a matrix form, wherein a codebook in an LTE protocol is the codebook quantization feedback method, and an LTE downlink 4 transmitting antenna codebook is shown in a table 2, and actually a precoding codebook and a channel information quantization codebook in LTE have the same meaning. In the following, for the sake of uniformity, a vector may also be considered as a matrix with dimension 1.

TABLE 2 LTE Downlink 4 transmit antenna codebook schematic

Codebook u_nTotal number of layers upsilon

Indexing

1 2 3 4

0 u₀＝[1 -1 -1 -1]^T W₀ ^{1} W₀ ^{1234}/2

1 u₁＝[1 -j 1 j]^T W₁ ^{1} W₁ ^{1234}/2

2 u₂＝[1 1 -1 1]^T W₂ ^{1} W₂ ^{3214}/2

3 u₃＝[1 j 1 -j]^T W₃ ^{1} W₃ ^{3214}/2

4W₄ ^{1} W₄ ^{1234}/2

5W₅ ^{1} W₅ ^{1234}/2

6W₆ ^{1} W₆ ^{1324}/2

7W₇ ^{1} W₇ ^{1324}/2

8 u₈＝[1 -1 1 1]^T W₈ ^{1} W₈ ^{1234}/2

9 u₉＝[1 -j -1 -j]^T W₉ ^{1} W₉ ^{1234}/2

10 u₁₀＝[1 1 1 -1]^T W₁₀ ^{1} W₁₀ ^{1324}/2

11 u₁₁＝[1 j -1 j]^T W₁₁ ^{1} W₁₁ ^{1324}/2

12 u₁₂＝[1 -1 -1 1]^T W₁₂ ^{1} W₁₂ ^{1234}/2

13 u₁₃＝[1 -1 1- 1]^T W₁₃ ^{1} W₁₃ ^{1324}/2

14 u₁₄＝[1 1 -1 -1]^T W₁₄ ^{1} W₁₄ ^{3214}/2

15 u₁₅＝[1 1 1 1]^T W₁₅ ^{1} W₁₅ ^{1234}/2

WhereinI is a unit matrix, W_k ^(j)A representation matrix W_kThe jth column vector of (1).A representation matrix W_kJ (d) of₁，j₂，...，j_nMatrix of columns, u_n ^HRepresents u_nThe conjugate transpose matrix of (a); wherein n represents a serial number and takes a value of 0-15.

With the development of communication technology, there is a higher demand for spectral efficiency in long term evolution Advanced (LTE-Advanced), and therefore, 8 antennas are also increased, for which 8 transmit antenna codebook feedbacks need to be designed for quantization feedback of channel information.

In the LTE standard, the minimum feedback unit of channel information is a sub-band (Subband), one sub-band is composed of several Resource Blocks (RBs), and each RB is composed of multiple Resource Elements (REs). RE is the minimum unit of time-frequency resources in LTE, and the LTE-A continues to use the resource representation method of LTE.

The idea of the prior art is to inherit a codebook feedback method in an LTE4 antenna and design an 8-antenna codebook, as shown in table 3:

TABLE 3A 8 antenna codebook schematic

<math> <mrow> <msub> <mi>M</mi> <mi>n</mi> </msub> <mo>=</mo> <msub> <mi>B</mi> <mi>n</mi> </msub> <mo>&CircleTimes;</mo> <msub> <mi>A</mi> <mi>n</mi> </msub> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <mn>1</mn> </mtd> <mtd> <mn>1</mn> </mtd> </mtr> <mtr> <mtd> <mo>-</mo> <mn>1</mn> </mtd> <mtd> <mn>1</mn> </mtd> </mtr> </mtable> </mfenced> <mo>&CircleTimes;</mo> <msub> <mi>W</mi> <mi>n</mi> </msub> </mrow> </math> Formula (1)

In the above formula (1):

n represents a serial number and is an integer value of 0 to 15;

M_nis an 8 x 8 matrix

W_nThe matrix is the same as the matrix defined in the LTE codebook.

The numbers in Table 4 represent the decimation method, specifically M corresponding to the decimation Index (Index) value_nThe columns in (1) construct codewords.

TABLE 4 decimation schematic of codeword structure

Index

Rank 1

Rank 2

Rank 3

Rank 4

Rank 5

Rank 6

Rank 7

Rank 8

0	1	15	125	1256	12356	123567	1234567	12345678
									1	1	15	125	1256	12356	123567	1234567	12345678
2	1	15	125	1256	12356	123567	1234567	12345678
									3	1	15	135	1357	13457	134578	1234578	12345678
4	1	15	125	1256	12356	123567	1234567	12345678
									5	1	15	135	1357	12357	123567	1234567	12345678
6	1	15	125	1256	12356	123567	1234567	12345678
									7	1	15	145	1458	13458	134578	1234578	12345678
8	1	15	145	1458	14568	124568	1234568	12345678
									9	1	15	145	1458	14568	124568	1234568	12345678
10	1	15	145	1458	14568	124568	1234568	12345678
									11	1	15	125	1256	12456	124568	1234568	12345678
12	1	15	125	1256	12456	124568	1234568	12345678
									13	1	15	125	1256	12456	124568	1234568	12345678
14	1	15	125	1256	12456	124568	1234568	12345678
									15	1	15	125	1256	12456	124568	1234568	12345678

One drawback of the prior art is that it is not possible to provide feedback of multiple accuracies, whereas in LTE-a SU-MIMO and MU-MIMO are combined into the same transmission mode, i.e. SU/MU dynamic switching mode, and therefore the codebook should also support feedback of various accuracies.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a method and a device for acquiring channel information, so as to solve the technical problem that a codebook in the prior art cannot support feedback of multiple accuracies.

In order to solve the above technical problem, the present invention provides a method for acquiring channel information, including:

for one sub-band, the terminal feeds back Rank Indicator (RI) information and at least one codebook index indicator (PMI) information of a channel to the base station; wherein the at least one PMI information includes first codebook index indication (PMI1) information;

the base station finds a column number of the 4-antenna codebook according to the RI information and the PMI1 informationAnd codeword W1 with index number PMI 1;

or

The base station finds a column number of the 8-antenna codebook according to the RI information and the PMI1 informationAnd codeword W1 with index number PMI 1; where v represents the rank of the channel represented by the RI information,represents a ceiling operation;

the base station obtains the channel information of the subband according to the code word W1, a matrix W2 and a function F (W1, W2).

Preferably, the 4-antenna codebook includes a 4-antenna codebook of 3GPP Long Term Evolution (LTE), or a codebook formed by a subset of the 4-antenna codebook of LTE; the 8-antenna codebook comprises a codebook with codewords having a block diagonal form.

Preferably, the 8-antenna codebook includes a modified codebook of an LTE 4-antenna codebook, or a codebook formed by a subset of the modified codebook.

Preferably, the transforming codebook comprises transforming all codewords V in the LTE4 antenna codebook intoAnd obtaining the codebook.

Preferably, the base station obtains the matrix W2 according to the feedback or convention of the terminal.

Preferably, when the codeword W1 is found from the 4-antenna codebook, the function F (W1, W2) includes:

<math> <mrow> <mi>F</mi> <mrow> <mo>(</mo> <mi>W</mi> <mn>1</mn> <mo>,</mo> <mi>W</mi> <mn>2</mn> <mo>)</mo> </mrow> <mi>W</mi> <mn>2</mn> <mo>&CircleTimes;</mo> <mi>W</mi> <mn>1</mn> <mo>;</mo> </mrow> </math>

<math> <mrow> <mi>F</mi> <mrow> <mo>(</mo> <mi>W</mi> <mn>1</mn> <mo>,</mo> <mi>W</mi> <mn>2</mn> <mo>)</mo> </mrow> <mo>=</mo> <mi>W</mi> <mn>1</mn> <mo>&CircleTimes;</mo> <mi>W</mi> <mn>2</mn> <mo>;</mo> </mrow> </math> or

F (W1, W2) ═ F (W1) × W2, whereO is a zero matrix;

when the codeword W1 is found from the 8-antenna codebook, the function F (W1, W2) includes:

F(W1，W2)＝W1×W2。

preferably, the matrix W2 is 1 matrix of m × v when v is greater than 2;

when upsilon is an even number, upsilon is m; when upsilon is an odd number, upsilon is m-1, wherein

Preferably, each column of the matrix W2 has a maximum of only 2 elements that are not 0.

Preferably, theWherein B is₁Is oneMatrix of (A), B₂Is oneA matrix of (a); b is₁Each column of which has only 1 element other than 0, B₂With 1 and only 1 element in each column that is not 0.

Preferably, the matrix B₁All elements other than 0 in (1) are 1; matrix B₂Elements in the set other than 0

In order to solve the above technical problem, the present invention further provides an apparatus for acquiring channel information, wherein:

a receiving module, configured to receive Rank Indicator (RI) information and at least one codebook index indicator (PMI) information of a channel fed back by a terminal; wherein the at least one PMI information includes first codebook index indication (PMI1) information;

a searching module for finding a column number of 4-antenna codebook according to the RI information and the PMI1 informationAnd codeword W1 with index number PMI 1;

or

For finding a column number of an 8-antenna codebook according to the RI information and the PMI1 informationAnd codeword W1 with index number PMI 1; where v represents the rank of the channel represented by the RI information,represents a ceiling operation;

and the acquisition module is used for acquiring the channel information of the sub-band according to the code word W1, a matrix W2 and a function F (W1, W2).

Preferably, the searching module is configured to obtain the matrix W2 according to the feedback or contract of the terminal.

Compared with the prior art, the channel information acquisition technology for multi-codebook joint feedback under 8 antennas can provide various precision modes, can be flexibly applied to feedback of channel information, realizes the technology of channel information based on multi-codebook joint feedback, and effectively utilizes feedback overhead.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic flow chart of a first embodiment of the present invention;

FIG. 2 is a schematic flow chart of a second embodiment of the present invention;

fig. 3 is a schematic structural diagram of a third embodiment of the present invention.

Detailed Description

The following detailed description will be provided with reference to the drawings, embodiments and application examples, so that how to apply the technical means to solve the technical problems and achieve the technical effects can be fully understood and implemented.

First, if not conflicting, embodiments of the present invention and individual features of the embodiments may be combined with each other within the scope of protection of the present invention. Additionally, the steps illustrated in the flow charts of the figures may be performed in a computer system such as a set of computer-executable instructions and, although a logical order is illustrated in the flow charts, in some cases, the steps illustrated or described may be performed in an order different than here.

One technical scheme of the invention is shown in figure 1, and mainly comprises the following steps:

step S110, for a sub band, the UE feeds back Rank Indicator (RI) information and at least one PMI information of a channel to the base station, wherein the PMI information comprises first codebook index indication (PMI1) information (when the at least one PMI information is PMI1, the information fed back by the UE to the base station is the RI information and the PMI1 information);

step S120, the base station receives the RI information and the PMI informationThen, according to the RI information and the PMI1 information, a column number is found from a 4-antenna codebookAnd codeword W1 with index number PMI1, where υ represents the rank of the channel represented by the RI information,represents a ceiling operation;

step S130, the base station also obtains a matrix W2 through the feedback or convention of the UE;

in step S140, the base station obtains the channel information of the sub band according to the codeword W1, the matrix W2 and the function F (W1, W2).

The 4-antenna codebook may be a 4-antenna codebook of LTE or a codebook composed of subsets of the 4-antenna codebook of LTE.

The function F (W1, W2) can be expressed as:

<math> <mrow> <mi>F</mi> <mrow> <mo>(</mo> <mi>W</mi> <mn>1</mn> <mo>,</mo> <mi>W</mi> <mn>2</mn> <mo>,</mo> <mo>)</mo> </mrow> <mo>=</mo> <mi>W</mi> <mn>2</mn> <mo>&CircleTimes;</mo> <mi>W</mi> <mn>1</mn> <mo>;</mo> </mrow> </math>

<math> <mrow> <mi>F</mi> <mrow> <mo>(</mo> <mi>W</mi> <mn>1</mn> <mo>,</mo> <mi>W</mi> <mn>2</mn> <mo>)</mo> </mrow> <mo>=</mo> <mi>W</mi> <mn>1</mn> <mo>&CircleTimes;</mo> <mi>W</mi> <mn>2</mn> <mo>;</mo> </mrow> </math> or

F (W1, W2) ═ F (W1) × W2, whereO is a zero matrix.

The matrix W2 is a matrix of 1 m multiplied by upsilon when upsilon is larger than 2; when upsilon is even number, m is equal to m, when upsilon is odd number, m-1, wherein

Furthermore, each column in the matrix W2 has at most 2 elements which are not 0, so that the function F (W1, W2) is calculated by using F (W1) multiplied by W2, the complexity is low, the calculation amount of the UE for selecting the code word is reduced, and the form of the code word can be obtainedWherein a and b are constants.

The matrix W2 may be further represented in the form:

$W2=\begin{array}{}\end{array}\left[\begin{array}{c}{B}_1\\ B_2\end{array}\right],$

wherein B is₁Is oneMatrix of (A), B₂Is oneOf the matrix of (a). B is₁Each column of which has only 1 element other than 0, B₂Each of which is one and only 1 is not0, or a salt thereof. Preferably, B₁All elements other than 0 in (1) are 1; preferably, B₂Elements in the set other than 0

Another technical scheme of the invention is shown in fig. 2, and mainly comprises the following steps:

step S210, for a sub band, the UE feeds back Rank Indicator (RI) information and at least one PMI information of a channel to the base station, wherein the PMI information comprises first codebook index indication (PMI1) information (when the at least one PMI information is PMI1, the information fed back by the UE to the base station is the RI information and the PMI1 information);

step S220, after receiving the RI information and the PMI information, the base station finds a column number of the RI information and the PMI1 information from an 8-antenna codebookAnd codeword W1 with index number PMI 1;

step S230, the base station also obtains a matrix W2 through the feedback or convention of the UE;

in step S240, the base station obtains the channel information of the sub band according to the codeword W1, the matrix W2 and the function F (W1, W2).

The function F (W1, W2) can be expressed as:

F(W1，W2)＝W1×W2。

the 8-antenna codebook may be a codebook in which codewords have a block diagonal form. Further, the 8-antenna codebook may be a modified codebook of an LTE 4-antenna codebook or a codebook formed by a subset of the modified codebook. The deformation codebook can deform all the code words V in the LTE4 antenna codebook intoAnd obtaining the codebook.

When upsilon is larger than 2, the matrix W2 is a 1 m multiplied by upsilon matrix; when upsilon is an even number, upsilon is m, and when upsilon is an odd number, upsilon is m-1, where m is an integer greater than 1, and may be determined according to the feedback accuracy level of the UE, for example.

Furthermore, each column in the matrix W2 has at most 2 elements which are not 0, so that the calculation using W1 xW 2 has low complexity, reduces the calculation amount when the UE selects the code word, and can obtain the form ofWherein a and b are constants.

The matrix W2 may be further represented in the form:

wherein B is₁Is oneMatrix of (A), B₂Is oneOf the matrix of (a). B is₁Each column of which has only 1 element other than 0, B₂With 1 and only 1 element in each column that is not 0. Preferably, B₁All elements other than 0 in (1) are 1; preferably, B₂Elements in the set other than 0

Application example one, a method for acquiring channel information, wherein:

and the UE acquires channel information through pilot frequency and channel estimation, and judges the RI information of the current channel, wherein upsilon represents the rank of the channel in the RI information.

For example when v is 5, then,the UE finds a codeword W1 from the corresponding layer-3 sub-codebook in the LTE codebook, assuming index number 1, and finds a suitable matrix W2, such thatThe UE can well represent the feature vector information of the channel, and feeds back the RI information (where upsilon is 5), the index information (equal to 1) of the codeword W1, and the information of the matrix W2 to the base station.

After receiving the RI information, the index number information of the code word W1 and the information of the matrix W2, the base station calculates according to the RI informationFinding out a code word with W1 as index number 1 from a corresponding layer 3 sub-codebook in a codebook of LTE, and using the code wordChannel information is obtained.

Application example two, a method for acquiring channel information, wherein:

and the UE acquires channel information through pilot frequency and channel estimation, and judges the RI information of the current channel, wherein upsilon represents the rank of the channel in the RI information.

For example when v is 7,the UE finds a codeword W1 from the corresponding layer-4 sub-codebook in the LTE codebook, so thatThe characteristic vector information of the channel can be well represented, and the matrix W2 is agreed in advance as follows:

$W2=\left[\begin{array}{ccccccc}1& 0& 0& 0& 0& 0& 0\\ 0& 1& 0& 0& 1& 0& 0\\ 0& 0& 1& 0& 0& 1& 0\\ 0& 0& 0& 1& 0& 0& 1\\ 1& 0& 0& 0& -1& 0& 0\\ 0& -1& 0& 0& 0& 1& 0\\ 0& 0& 1& 0& 0& 0& -1\\ 0& 0& 0& -1& 0& 0& 0\end{array}\right],$

wherein the behavior of the matrix W2 is swapped for an equivalent application instance;

or

Convention W2 is:

$W2=\left[\begin{array}{ccccccc}1& 0& 0& 0& 0& 0& 0\\ 0& 1& 0& 0& 1& 0& 0\\ 0& 0& 1& 0& 0& 1& 0\\ 0& 0& 0& 1& 0& 0& 1\\ j& 0& 0& 0& -j& 0& 0\\ 0& -j& 0& 0& 0& 1& 0\\ 0& 0& j& 0& 0& 0& -j\\ 0& 0& 0& -j& 0& 0& 0\end{array}\right],$

where the behavior of the matrix W2 is swapped for an application instance.

Assuming that the code word W1 selects the code word with index number 2 to better represent the channel information, the UE feeds back RI information (υ 7), index number information (equal to 2) of the code word W1, and information of the matrix W2.

After receiving the RI information, the index information of the codeword W1 and the information of the matrix W2, the base station calculates according to the RI informationFinding out a code word W1 with index number of 2 from a corresponding layer-4 sub-codebook in the LTE codebook, and using the code wordChannel information is obtained.

Application example three, a method for acquiring channel information, wherein:

and the UE acquires channel information through pilot frequency and channel estimation, and judges the RI information of the current channel, wherein upsilon represents the rank of the channel in the RI information.

For example when v is 4, then,the UE finds a codeword W1 from the corresponding layer-2 sub-codebook in the LTE codebook, so thatThe eigenvector information of the channel can be well represented, and the matrix W2 can be selected from the following codebook:

$\left[\begin{array}{cccc}1& 0& 1& 0\\ 0& 1& 0& 1\\ 1& 0& 1& 0\\ 0& -1& 0& -1\end{array}\right]$ or $\left[\begin{array}{cccc}1& 0& 1& 0\\ 0& 1& 0& 1\\ j& 0& j& 0\\ 0& -j& 0& -j\end{array}\right];$

Assuming code word W1 with index number 2 is selected, the matrix W2 selects the 1 st matrix at the top edgeThe channel information can be well characterized, and the UE feeds back RI information (υ ═ 4), index information (equal to 2) corresponding to the codeword W1, and information of the matrix W2.

After receiving the RI information, the index number information corresponding to the codeword W1 and the information of the matrix W2, the base station calculates according to the RI informationFinding out a codeword W1 with index number 2 from a corresponding layer 2 sub-codebook in LTE codebook, and using the codewordChannel information is obtained.

Application example four, a method for acquiring channel information, wherein:

and the UE acquires channel information through pilot frequency and channel estimation, and judges the RI information of the current channel, wherein upsilon represents the rank of the channel in the RI information.

For example when v is 4, then,the UE finds a codeword W1 from the corresponding layer-2 sub-codebook in the LTE codebook, so thatThe eigenvector information of the channel can be well represented, and the matrix W2 can be selected from the following codebook:

$\left[\begin{array}{cc}1& 1\\ -1& 1\end{array}\right]$ or $\left[\begin{array}{cc}1& 1\\ -j& j\end{array}\right];$

Assuming code word W1 with index number 2 is selected, the matrix W2 selects the 1 st matrix at the top edgeThe channel information can be well characterized, the UE feeds back RI information (υ 4), index information (equal to 2) corresponding to the codeword W1, and information of the matrix W2 to the base station.

After receiving the RI information (υ 4), the index information corresponding to the codeword W1, and the information of the matrix W2, the base station calculates the RI informationFinding out a codeword W1 with index number 2 from a corresponding layer 2 sub-codebook in LTE codebook, and using the codewordChannel information is obtained.

Application example five, a method for acquiring channel information, wherein:

and the UE acquires channel information through pilot frequency and channel estimation, and judges the RI information of the current channel, wherein upsilon represents the rank of the channel in the RI information.

For example when v is 4, then,the LTE deformed codebook is agreed as follows:

deforming all code words V in LTE4 antenna codebook intoAnd then the obtained 8-dimensional codebook is formed.

The UE finds a code word W1 from a layer-4 sub-codebook corresponding to the LTE modified codebook, so that W1 xW 2 can well represent the characteristic vector information of the channel, and the matrix W2 can be selected from the following codebooks:

$\left[\begin{array}{cccc}1& 0& 1& 0\\ 0& 1& 0& 1\\ 1& 0& 1& 0\\ 0& -1& 0& -1\end{array}\right]$ or $\left[\begin{array}{cccc}1& 0& 1& 0\\ 0& 1& 0& 1\\ j& 0& j& 0\\ 0& -j& 0& -j\end{array}\right];$

Assuming code word W1 with index number 2 is selected, the matrix W2 selects the 1 st matrix at the top edgeThe channel information can be well characterized, and the UE feeds back RI information (υ ═ 4), index information (equal to 2) corresponding to the codeword W1, and information of the matrix W2.

After receiving the RI information, the index information corresponding to the codeword W1, and the information of the matrix W2, the base station calculates the RI informationAnd finding a codeword W1 with index number of 2 from a corresponding layer-4 sub-codebook in the LTE codebook, and obtaining channel information by using W1 multiplied by W2.

Application example six, a method for acquiring channel information, wherein:

and the UE acquires channel information through pilot frequency and channel estimation, and judges the RI information of the current channel, wherein upsilon represents the rank of the channel in the RI information.

For example when v is 3, then,the LTE deformed codebook is agreed as follows:

deforming all code words V in LTE4 antenna codebook intoAnd then the obtained 8-dimensional codebook is formed.

The UE finds a code word W1 from a layer-4 sub-codebook corresponding to the LTE modified codebook, so that W1 xW 2 can well represent the characteristic vector information of the channel, and the matrix W2 can be selected from the following codebooks:

$\left[\begin{array}{cccc}1& 0& 1& 0\\ 0& 1& 0& 1\\ 1& 0& 1& 0\\ 0& -1& 0& -1\end{array}\right],$ $\left[\begin{array}{cccc}1& 0& 1& 0\\ 0& 1& 0& 1\\ j& 0& j& 0\\ 0& -j& 0& -j\end{array}\right],$ $\left[\begin{array}{cccc}j& 0& j& 0\\ 0& j& 0& j\\ 1& 0& 1& 0\\ 0& -1& 0& -1\end{array}\right]$ or $\left[\begin{array}{cccc}1& 0& 1& 0\\ 0& 1& 0& 1\\ 1& 0& 1& 0\\ 0& -j& 0& -j\end{array}\right];$

Assuming codeword W1 of index number 2 is selected, matrix W2 selects the 3 rd matrixThe channel information can be well characterized, the UE feeds back RI information (υ 4), index information (equal to 2) corresponding to the codeword W1, and information of the matrix W2, where the matrix W2 information is fed back in the form of codebook index.

After receiving the RI information (υ 4), the index information (equal to 2) corresponding to the codeword W1, and the information of the matrix W2, the base station calculates the RI informationFinding a code word W1 with the index number of 2 from a corresponding sub-codebook with the layer of 4 in the deformed codebook of the LTE, and according to the codebook index number representing the W2 information, selecting the code word W1 from the codebook

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

Find the 3 rd matrixAs a matrix W2, and channel information is obtained using W1 × W2.

In a third embodiment, as shown in fig. 3, an apparatus for acquiring channel information mainly includes a receiving module 310, a searching module 320, and an acquiring module 330, where:

a receiving module 310, configured to receive Rank Indicator (RI) information and at least one codebook index indicator (PMI) information of a channel fed back by a terminal; wherein the at least one PMI information includes first codebook index indication (PMI1) information;

a searching module 320 connected to the receiving module 310, configured to find a column number of the 4-antenna codebook according to the RI information and the PMI1 informationAnd codeword W1 with index number PMI 1;

or

For finding a column number of an 8-antenna codebook according to the RI information and the PMI1 informationAnd codeword W1 with index number PMI 1; where v represents the rank of the channel represented by the RI information,represents a ceiling operation;

an obtaining module 330, connected to the searching module 320, is configured to obtain channel information of the sub-band according to the codeword W1, a matrix W2, and a function F (W1, W2).

Wherein,

the search module 320 is used to obtain the matrix W2 according to the feedback or convention of the terminal.

Those skilled in the art will appreciate that the modules or steps of the invention described above can be implemented in a general purpose computing device, centralized on a single computing device or distributed across a network of computing devices, and optionally implemented in program code that is executable by a computing device, such that the modules or steps are stored in a memory device and executed by a computing device, fabricated separately into integrated circuit modules, or fabricated as a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

Although the embodiments of the present invention have been described above, the above descriptions are only for the convenience of understanding the present invention, and are not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. A method for acquiring channel information is characterized by comprising the following steps:

for one sub-band, the terminal feeds back the rank indicator RI information and at least one codebook index indication PMI information of a channel to the base station; wherein the at least one PMI information comprises first codebook index indication PMI1 information;

the base station finds a column number of the 4-antenna codebook according to the RI information and the PMI1 informationAnd codeword W1 with index number PMI 1; wherein upsilon represents the rank of the channel represented by the RI information,represents a ceiling operation;

or

The base station finds a column number of the 8-antenna codebook according to the RI information and the PMI1 informationAnd codeword W1 with index number PMI 1; where v represents the rank of the channel represented by the RI information,represents a ceiling operation;

the base station obtains the channel information of the sub-band according to the code word W1, a matrix W2 and a function F (W1, W2);

the base station obtains the matrix W2 according to the feedback or convention of the terminal.

2. The method of claim 1, wherein:

the 4-antenna codebook comprises a 4-antenna codebook of a 3GPP long term evolution LTE or a codebook formed by subsets of the 4-antenna codebook of the LTE;

the 8-antenna codebook comprises a codebook with codewords having a block diagonal form.

3. The method of claim 2, wherein:

the 8-antenna codebook comprises a deformation codebook of an LTE4 antenna codebook or a codebook formed by a subset of the deformation codebook.

4. The method of claim 3, wherein:

the deformation codebook comprises all code words V in an LTE4 antenna codebookIs shaped as $\left[\begin{array}{cc}V& O\\ O& V\end{array}\right]$ And obtaining the codebook.

5. The method of claim 1, wherein:

when the codeword W1 is found from the 4-antenna codebook, the function F (W1, W2) includes:

<math> <mrow> <mi>F</mi> <mrow> <mo>(</mo> <mi>W</mi> <mn>1</mn> <mo>,</mo> <mi>W</mi> <mn>2</mn> <mo>)</mo> </mrow> <mo>=</mo> <mi>W</mi> <mn>2</mn> <mo>&CircleTimes;</mo> <mi>W</mi> <mn>1</mn> <mo>;</mo> </mrow> </math>

<math> <mrow> <mi>F</mi> <mrow> <mo>(</mo> <mi>W</mi> <mn>1</mn> <mo>,</mo> <mi>W</mi> <mn>2</mn> <mo>)</mo> </mrow> <mo>=</mo> <mi>W</mi> <mn>1</mn> <mo>&CircleTimes;</mo> <mi>W</mi> <mn>2</mn> <mo>;</mo> </mrow> </math> or

F (W1, W2) ═ F (W1) × W2, where $F\left(W1\right)=\left[\begin{array}{cc}W1& O\\ O& W1\end{array}\right],$ O is a zero matrix;

when the codeword W1 is found from the 8-antenna codebook, the function F (W1, W2) includes:

F(W1，W2)＝W1×W2。

6. the method of claim 1, wherein:

the matrix W2 is a matrix of 1 m multiplied by upsilon when upsilon is larger than 2;

when upsilon is an even number, upsilon is m; when upsilon is an odd number, upsilon is m-1, wherein m isWhere v represents the rank of the channel represented by the RI information,indicating a ceiling operation.

7. The method of claim 6, wherein:

each column of the matrix W2 has a maximum of only 2 elements that are not 0.

8. The method of claim 6, wherein:

the $W2=\left[\begin{array}{c}{B}_1\\ B_2\end{array}\right],$ Wherein B is₁Is oneMatrix of (A), B₂Is oneA matrix of (a); b is₁Each column of which has only 1 element other than 0, B₂With 1 and only 1 element in each column that is not 0.

9. The method of claim 8, wherein:

matrix B₁All elements other than 0 in (1) are 1;

matrix B₂Elements in the set other than 0

10. The device for acquiring the channel information is characterized by comprising a receiving module, a searching module and an acquiring module:

the receiving module is used for receiving rank indicator RI information and at least one codebook index indication PMI information of a channel fed back by a terminal; wherein the at least one PMI information comprises first codebook index indication PMI1 information;

the searching module is configured to find a column number of a 4-antenna codebook according to the RI information and the PMI1 informationAnd codeword W1 with index number PMI 1; wherein upsilon represents the rank of the channel represented by the RI information,represents a ceiling operation;

or

For finding a column number of an 8-antenna codebook according to the RI information and the PMI1 informationAnd codeword W1 with index number PMI 1; where v represents the rank of the channel represented by the RI information,represents a ceiling operation;

the obtaining module is configured to obtain channel information of a subband according to the codeword W1, a matrix W2, and a function F (W1, W2);

the search module is used for obtaining the matrix W2 according to the feedback or convention of the terminal.