Method, system and device for transmitting pre-coded indication information and determining pre-coding matrix

• US 9,356,669 B2
• Filed: 10/30/2013
• Issued: 05/31/2016
• Est. Priority Date: 10/29/2012
• Status: Active Grant

• Current Assignee: Datang Mobile Communications Equipment Company Limited (China Information Communication Technology Group Co. Ltd.)
• Original Assignee: China Academy of Telecom Technology (China Information Communication Technology Group Co. Ltd.)
• Inventors: Gao, Qiubin, Tamrakar, Rakesh, Su, Xin
• Primary Examiner(s): Perez, James M
• Application Number:
  US14/434,396
• Publication Number:
  US 20150280798A1
• Time in Patent Office: 944 Days
• Field of Search: 375219-222, 375229-232, 375259-285, 375295-352
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0469 taking special antenna structures, e.g. cross polarized antennas into account
• CPC Class Codes: H04B 7/0478 Special codebook structures directed to feedback optimisation
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

An embodiment of the present application relates to the technical field of wireless communications, in particular to a method, system and device for transmitting pre-coded indication information and determining a pre-coding matrix. In the prior art, the existing codebook is designed for horizontal beamforming/pre-coding, and will reduce the performance thereof if directly applied in three-dimensional beamforming/pre-coding technique. The present application solves the problem. The method in the embodiment of the present application comprises: a user equipment (UE) determines and transmits first pre-coded indication information and second pre-coding indication information, the pre-coding matrix being equal to the function matrix of a first component pre-coding matrix and a second component pre-coding matrix, a sub-matrix on the diagonal of the first component pre-coding matrix being the Kronecker product of two diagonal matrixes, the second component pre-coding matrix being formed by a beam rotation vector equaling to the Kronecker product of two vectors. The embodiment of the present application improves the performance of the three-dimensional beamforming/pre-coding technique.

Claims

1. A method for transmitting a pre-coding indicator, the method comprising:

determining, by a UE, a first pre-coding indicator and a second pre-coding indicator, the first pre-coding indicator and the second pre-coding indicator corresponding to a pre-coding matrix which is equal to a matrix as a function of a first component pre-coding matrix and a second component pre-coding matrix, the first component pre-coding matrix being a block diagonal matrix with sub-matrixes on the diagonal being a Kronecker product of two diagonal matrixes, and the second component pre-coding matrix being constructed by beam-rotating vectors, each of the beam-rotating vectors being equal to a Kronecker product of two vectors; and

transmitting, by the UE, the first pre-coding indicator and the second pre-coding indicator to a network side.

2. The method according to claim 1, wherein the first component pre-coding matrix is:

3. The method according to claim 2, wherein U_H represents an element in a set of beam-forming vectors {U_H,p:

p=0,1, . . . , N_H−

1} with U_H=U_H,k and 0≦

k≦

N_H−

1, N_H represents a positive integer; and

U_V represents an element in a set of beam-forming vectors {U_V,q;

q=0,1, . . . , N_V−

1} with U_V=U_V,n and 0≦

n≦

N_V−

1, N_V represents a positive integer.

4. The method according to claim 3, wherein the UE determines the first pre-coding indicator in the equation of:

i₁=n×

N_H+k or i₁=k×

N_V+n,

i₁ represents the first pre-coding indicator.

5. The method according to claim 1, wherein the second component pre-coding matrix is a product of a (2D_HD_V)×

r -dimension matrix and a power normalization coefficient, r represents the number of columns in the pre-coding matrix; and

the second component pre-coding matrix is;

6. The method according to claim 1, wherein the determining, by the UE, the first pre-coding indicator and the second pre-coding indicator comprises:

selecting, by the UE, the first component pre-coding matrix from a set of first component pre-coding matrixes and determining the first pre-coding indicator corresponding to the selected first component pre-coding matrix, and selecting the second component pre-coding matrix from a set of second component pre-coding matrixes and determining the second pre-coding indicator corresponding to the selected second component pre-coding matrix;

or,

wherein the determining, by the UE, the first pre-coding indicator and the second pre-coding indicator comprises;

determining, by the UE, at least one pre-coding matrix and determining first pre-coding indicator and second pre-coding indicator corresponding to the at least one pre-coding matrix according to a correspondence relationship between the first pre-coding indicator, the second pre-coding indicator and the pre-coding matrix; and

determining, by the UE, that one of the determined first pre-coding indicator and one of the determined second pre-coding indicator are the first pre-coding indicator and the second pre-coding indicator to be transmitted to the network side.

7. The method according to claim 1, wherein the UE determines that a product of the first component pre-coding matrix and the second component pre-coding matrix is the pre-coding matrix.

8. A method for determining a pre-coding matrix, the method comprising:

receiving, by a network-side device, a first pre-coding indicator and a second pre-coding indicator from a UE; and

determining, by the network-side device, a pre-coding matrix corresponding to the first pre-coding indicator and the second pre-coding indicator,

the pre-coding matrix is equal to a matrix as a function of a first component pre-coding matrix and a second component pre-coding matrix, the first component pre-coding matrix is a block diagonal matrix with sub-matrixes on the diagonal being a Kronecker product of two diagonal matrixes, and the second component pre-coding matrix is constructed by beam-rotating vectors, each of the beam-rotating vectors is equal to a Kronecker product of two vectors.

9. The method according to claim 8, wherein the determining, by the network-side device, the pre-coding matrix comprises:

determining, by the network-side device, the first component pre-coding matrix corresponding to the first pre-coding indicator and determining the second component pre-coding matrix corresponding to the second pre-coding indicator; and

determining, by the network-side device, that a product of the first component pre-coding matrix and the second component pre-coding matrix is the pre-coding matrix;

or,

determining, by the network-side device, the pre-coding matrix comprises;

determining, by the network-side device, the pre-coding matrix corresponding to the received first pre-coding indicator and second pre-coding indicator according to a preset correspondence relationship between the first pre-coding indicator, the second pre-coding indicator and the pre-coding matrix.

10. The method according to claim 9, wherein the network-side device determines the first component pre-coding matrix corresponding to the first pre-coding indicator in the equation of:

11. The method according to claim 9, wherein the second component pre-coding matrix is a product of a (2D_HD_V)×

r -dimension matrix and a power normalization coefficient, r represents the number of columns in the pre-coding matrix; and

the second component pre-coding matrix is;

12. A UE for transmitting a pre-coding indicator, the UE comprising:

a first determining device configured to determine a first pre-coding indicator and a second pre-coding indicator, the first pre-coding indicator and the second pre-coding indicator corresponding to a pre-coding matrix which is equal to a matrix as a function of a first component pre-coding matrix and a second component pre-coding matrix, the first component pre-coding matrix being a block diagonal matrix with sub-matrixes on the diagonal being a Kronecker product of two diagonal matrixes, and the second component pre-coding matrix being constructed by beam-rotating vectors, each of the beam-rotating vectors being equal to a Kronecker product of two vectors; and

a transmitting device configured to transmit the first pre-coding indicator and the second pre-coding indicator to a network side.

13. The UE according to claim 12, wherein the first component pre-coding matrix is:

14. The UE according to claim 12, wherein the second component pre-coding matrix is a product of a (2D_HD_V)×

r -dimension matrix and a power normalization coefficient, r represents the number of columns in the pre-coding matrix; and

the second component pre-coding matrix is;

15. The UE according to claim 12, wherein the first determining device is configured:

to select the first component pre-coding matrix from a set of first component pre-coding matrixes and to determine the first pre-coding indicator corresponding to the selected first component pre-coding matrix, and to select the second component pre-coding matrix from a set of second component pre-coding matrixes and to determine the second pre-coding indicator corresponding to the selected second component pre-coding matrix;

or,

wherein the first determining device is configured;

to determine at least one pre-coding matrix;

to determine the first pre-coding indicator and the second pre-coding indicator corresponding to the at least one pre-coding matrix according to a correspondence relationship between the first pre-coding indicator, the second pre-coding indicator and the pre-coding matrix; and

to determine that one of the determined first pre-coding indicator and one of the determined second pre-coding indicator are the first pre-coding indicator and the second pre-coding indicator to be transmitted to the network side.

16. The UE according to claim 12, wherein the first determining device is configured to determine that a product of the first component pre-coding matrix and the second component pre-coding matrix is the pre-coding matrix.

17. A network-side device for determining a pre-coding matrix, the network-side device comprising:

a receiving device configured to receive a first pre-coding indicator and a second pre-coding indicator from a UE; and

a second determining device configured to determine a pre-coding matrix corresponding to the first pre-coding indicator and the second pre-coding indicator,

the pre-coding matrix is equal to a matrix as a function of a first component pre-coding matrix and a second component pre-coding matrix, the first component pre-coding matrix is a block diagonal matrix with sub-matrixes on the diagonal being a Kronecker product of two diagonal matrixes, and the second component pre-coding matrix is constructed by beam-rotating vectors, each of the beam-rotating vectors is equal to a Kronecker product of two vectors.

18. The network-side device according to claim 17, wherein the second determining device is configured:

to determine the first component pre-coding matrix corresponding to the first pre-coding indicator, to determine the second component pre-coding matrix corresponding to the second pre-coding indicator and to determine that a product of the first component pre-coding matrix and the second component pre-coding matrix is the pre-coding matrix;

or,

wherein the second determining device is configured;

to determine the pre-coding matrix corresponding to the received first pre-coding indicator and second pre-coding indicator according to a preset correspondence relationship between the first pre-coding indicator, the second pre-coding indicator and the pre-coding matrix.

19. The network-side device according to claim 18, wherein the second determining device is configured to determine the first component pre-coding matrix corresponding to the first pre-coding indicator in the equation of:

20. The network-side device according to claim 18, wherein the second component pre-coding matrix is a product of a (2D_HD_V)×

r -dimension matrix and a power normalization coefficient, r represents the number of columns in the pre-coding matrix; and

the second component pre-coding matrix is;