Method for determining precoding matrix indicator, receiving device, and sending device

1. A method comprising:

selecting, by a receive end, a precoding matrix W from a codebook based on a reference signal from a transmit end, wherein the precoding matrix W is a product of a first matrix W1 and a second matrix W2, wherein

the first matrix W1 comprises N B block matrices X i , wherein N B is an integer greater than one, and the first matrix W1 is indicated as W1=diag{X 1 , . . . , X N B }, wherein an index i of the block matrix X i is greater than or equal to one and less than or equal to N B , wherein a column X ij of each block matrix X i is a kronecker product of a first vector A ij in a first codebook A i and a second vector B ij in a second codebook B i , that is, X ij =A ij ⊗B ij , wherein a quantity N2 of second vectors in the second codebook B i is less than or equal to a quantity N1 of first vectors in the first codebook A i ; and

sending, by the receive end, a precoding matrix indicator (PMI) corresponding to the precoding matrix W to the transmit end.

2. The method according to claim 1 , the second matrix W2 is used to select at least one column vector of the first matrix W1 to constitute the precoding matrix W, or is used to perform a weighted combination on column vectors of the first matrix W1 to constitute the precoding matrix W.

3. The method according to claim 1 , wherein the first matrix W1 is a matrix that indicates a channel characteristic of a wideband, and the second matrix W2 is a matrix that indicates a channel characteristic of a sub-band.

4. The method according to claim 1 , N B is a quantity of polarization directions, or a quantity of antenna groups.

5. The method according to claim 1 , wherein

the first vector A ij is a discrete Fourier transform (DFT) vector; and

the second vector B ij is a DFT vector.

6. The method according to claim 1 , wherein the first codebook A i corresponds to a horizontal direction of a two-dimensional planar array antenna, and the second codebook B i corresponds to a vertical direction of the two-dimensional planar array antenna.

7. A method comprising:

sending, by a transmit end, a reference signal to a receive end;

receiving, by the transmit end, a precoding matrix indicator (PMI) from the receive end; and

determining, by the transmit end according to the PMI, a precoding matrix W, wherein the precoding matrix W is a product of a first matrix W1 and a second matrix W2, wherein

the first matrix W1 comprises N B block matrices X i , wherein N B is an integer greater than one, and the first matrix W1 is indicated as W1=diag{X 1 , . . . , X N B }, wherein an index i of the block matrix X i is greater than or equal to one and less than or equal to N B , wherein a column X ij of each block matrix X i is a kronecker product of a first vector A ij in a first codebook A i and a second vector B ij in a second codebook B i , that is, X ij =A ij ⊗B ij , wherein a quantity N2 of second vectors in the second codebook B i is less than or equal to a quantity N1 of first vectors in the first codebook A i .

8. The method according to claim 7 , the second matrix W2 is used to select at least one column vector of the first matrix W1 to constitute the precoding matrix W, or is used to perform a weighted combination on column vectors of the first matrix W1 to constitute the precoding matrix W.

9. The method according to claim 7 , wherein the first matrix W1 is a matrix that indicates a channel characteristic of a wideband, and the second matrix W2 is a matrix that indicates a channel characteristic of a sub-band.

10. The method according to claim 7 , N B is a quantity of polarization directions, or a quantity of antenna groups.

11. The method according to claim 7 , wherein

the first vector A ij is a discrete Fourier transform (DFT) vector; and

the second vector B ij is a DFT vector.

12. The method according to claim 7 , wherein the first codebook A i corresponds to a horizontal direction of a two-dimensional planar array antenna, and the second codebook B i corresponds to a vertical direction of the two-dimensional planar array antenna.

13. An apparatus comprising:

a storage medium including executable instructions; and

a processor;

wherein the executable instructions, when executed by the processor, cause the apparatus to:

select a precoding matrix W from a codebook based on a reference signal from a transmit end, wherein the precoding matrix W is a product of a first matrix W1 and a second matrix W2, wherein

the first matrix W1 comprises N B block matrices X i , wherein N B is an integer greater than one, and the first matrix W1 is indicated as W1=diag{X 1 , . . . , X N B }, wherein an index i of the block matrix X i is greater than or equal to one and less than or equal to N B , wherein a column X ij of each block matrix X i is a kronecker product of a first vector A ij in a first codebook A i and a second vector B ij in a second codebook B i , that is, X ij =A ij ⊗B ij , wherein a quantity N2 of second vectors in the second codebook B i is less than or equal to a quantity N1 of first vectors in the first codebook A i ; and

send a precoding matrix indicator (PMI) corresponding to the precoding matrix W to the transmit end.

14. The apparatus according to claim 13 , the second matrix W2 is used to select at least one column vector of the first matrix W1 to constitute the precoding matrix W, or is used to perform a weighted combination on column vectors of the first matrix W1 to constitute the precoding matrix W.

15. The apparatus according to claim 13 , wherein the first matrix W1 is a matrix that indicates a channel characteristic of a wideband, and the second matrix W2 is a matrix that indicates a channel characteristic of a sub-band.

16. The apparatus according to claim 13 , N B is a quantity of polarization directions, or a quantity of antenna groups.

17. The apparatus according to claim 13 , wherein

the first vector A ij is a discrete Fourier transform (DFT) vector; and

the second vector B ij is a DFT vector.

18. The apparatus according to claim 13 , wherein the first codebook A i corresponds to a horizontal direction of a two-dimensional planar array antenna, and the second codebook B i corresponds to a vertical direction of the two-dimensional planar array antenna.

19. An apparatus comprising:

a storage medium including executable instructions; and

a processor;

wherein the executable instructions, when executed by the processor, cause the apparatus to:

send a reference signal to a receive end;

receive a precoding matrix indicator (PMI) from the receive end; and

determine, according to the PMI, a precoding matrix W, the precoding matrix W is a product of a first matrix W1 and a second matrix W2, wherein

the first matrix W1 comprises N B block matrices X i , wherein N B is an integer greater than one, and the first matrix W1 is indicated as W1=diag{X 1 , . . . , X N B }, wherein an index i of the block matrix X i is greater than or equal to one and less than or equal to N B , wherein a column X ij of each block matrix X i is a kronecker product of a first vector A ij in a first codebook A i and a second vector B ij in a second codebook B i , that is, X ij =A ij ⊗B ij , wherein a quantity N2 of second vectors in the second codebook B i is less than or equal to a quantity N1 of first vectors in the first codebook A i .

20. The apparatus according to claim 19 , the second matrix W2 is used to select at least one column vector of the first matrix W1 to constitute the precoding matrix W, or is used to perform a weighted combination on column vectors of the first matrix W1 to constitute the precoding matrix W.

21. The apparatus according to claim 19 , wherein the first matrix W1 is a matrix that indicates a channel characteristic of a wideband, and the second matrix W2 is a matrix that indicates a channel characteristic of a sub-band.

22. The apparatus according to claim 19 , N B is a quantity of polarization directions, or a quantity of antenna groups.

23. The apparatus according to claim 19 , wherein

the first vector A ij is a discrete Fourier transform (DFT) vector; and

the second vector B ij is a DFT vector.

24. The apparatus according to claim 19 , wherein the first codebook A i corresponds to a horizontal direction of a two-dimensional planar array antenna, and the second codebook B i corresponds to a vertical direction of the two-dimensional planar array antenna.

25. An apparatus comprising:

a processor, configured to select a precoding matrix W from a codebook based on a reference signal from a transmit end, wherein the precoding matrix W is a product of a first matrix W1 and a second matrix W2, wherein

the first matrix W1 comprises N B block matrices X i , wherein N B is an integer greater than one, and the first matrix W1 is indicated as W1=diag{X 1 , . . . , X N B }, wherein an index i of the block matrix X i is greater than or equal to one and less than or equal to N B , wherein a column X ij of each block matrix X i is a kronecker product of a first vector A ij in a first codebook A i and a second vector B ij in a second codebook B i , that is, X ij =A ij ⊗B ij , wherein a quantity N2 of second vectors in the second codebook B i is less than or equal to a quantity N1 of first vectors in the first codebook A i ; and

a transmitter, configured to send a precoding matrix indicator (PMI) corresponding to the precoding matrix W to the transmit end.

26. An apparatus comprising:

a transmitter, configured to send a reference signal to a receive end;

a receiver, configured to receive a precoding matrix indicator (PMI) from the receive end; and

a processor, configured to determine a precoding matrix W according to the PMI, wherein the precoding matrix W is a product of a first matrix W1 and a second matrix W2, wherein

the first matrix W1 comprises N B block matrices X i , wherein N B is an integer greater than one, and the first matrix W1 is indicated as W1=diag{X 1 , . . . , X N B }, wherein an index i of the block matrix X i is greater than or equal to one and less than or equal to N B , wherein a column X ij of each block matrix X i is a kronecker product of a first vector A ij in a first codebook A i and a second vector B ij in a second codebook B i , that is, X ij =A ij ⊗B ij , wherein a quantity N2 of second vectors in the second codebook B i is less than or equal to a quantity N1 of first vectors in the first codebook A i .

27. A non-transitory computer readable storage medium, configured to store executable instructions which, when executed by a processor, cause the processor to perform operations comprising:

selecting a precoding matrix W from a codebook based on a reference signal from a transmit end, wherein the precoding matrix W is a product of a first matrix W1 and a second matrix W2, wherein

the first matrix W1 comprises N B block matrices X i , wherein N B is an integer greater than one, and the first matrix W1 is indicated as W1=diag{X 1 , . . . , X N B }, wherein an index i of the block matrix X i is greater than or equal to one and less than or equal to N B , wherein a column X ij of each block matrix X i is a kronecker product of a first vector A ij in a first codebook A i and a second vector B ij in a second codebook B i , that is, X ij =A ij ⊗B ij , wherein a quantity N2 of second vectors in the second codebook B i is less than or equal to a quantity N1 of first vectors in the first codebook A i ; and

sending a precoding matrix indicator (PMI) corresponding to the precoding matrix W to the transmit end.

28. A non-transitory computer readable storage medium, configured to store executable instructions which, when executed by a processor, cause the processor to perform operations comprising:

sending a reference signal to a receive end;

receiving a precoding matrix indicator (PMI) from the receive end; and

determining a precoding matrix W according to the PMI, wherein the precoding matrix W is a product of a first matrix W1 and a second matrix W2, wherein

the first matrix W1 comprises N B block matrices X i , wherein N B is an integer greater than one, and the first matrix W1 is indicated as W1=diag{X 1 , . . . , X N B }, wherein an index i of the block matrix X i is greater than or equal to one and less than or equal to N B , wherein a column X ij of each block matrix X i is a kronecker product of a first vector A ij in a first codebook A i and a second vector B ij in a second codebook B i , that is, X ij =A ij ⊗B ij , wherein a quantity N2 of second vectors in the second codebook B i is less than or equal to a quantity N1 of first vectors in the first codebook A i .