PRECODING WITH A CODEBOOK FOR A WIRELESS SYSTEM

• US 20180152230A1
• Filed: 11/28/2017
• Published: 05/31/2018
• Est. Priority Date: 02/14/2006
• Status: Abandoned Application

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: KHOJASTEPOUR, Mohammad Ali
• Application Number:
  US15/824,612
• Publication Number:
  US 20180152230A1
• Time in Patent Office: Days
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/046 taking physical layer constraints into account
• CPC Class Codes: H04B 7/0486 taking channel rank into account
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A base station used in a wireless communications system with multiple transmission ranks is disclosed. The base station comprises a memory to store a codebook for a transmission rank, a beamforming controller to precode data with a precoding matrix selected from the codebook, and a transmitter to transmit the precoded data to a user equipment, wherein the precoding matrix is selected according to a first description and a second description, which are unique to the precoding matrix, and wherein the second description provides a finer description of the codebook than the first description. Other methods, systems, and apparatuses also are disclosed.

Claims

1-9. -9. (canceled)

10. A user equipment which communicates a base station, the user equipment comprising:

a memory configured to hold a codebook which is common to the user equipment and the base station;

wherein the codebook is set for each of a number of transmission rank;

a transmitter configured to transmit, to the base station, a channel state information, which the channel state information includes a channel quality information (CQI), rank indicator indicating transmission rank, and a precoding matrix indicator;

a receiver configured to receive, from the base station, a data coded with a precoding matrix of the codebook selected based on two indices; and

wherein the codebook is for the CSI reporting.

11. The user equipment according to claim 10, wherein

the channel state information indicates a precoding matrix of the codebook.

12. The user equipment according to claim 10, wherein

the two indices are determined based on the channel state information.

13. The user equipment according to claim 10, wherein

the two indices are unique to the precoding matrix.

14. The user equipment according to claim 10, wherein

the codebook is a set of precoding matrix.

15. The user equipment according to claim 10, wherein

the codebook comprises a vector codebook.

16. The user equipment according to claim 10, wherein

the precoding matrix is determined by calculation.

17. The user equipment according to claim 10, wherein

a first index of the two indices provides a finer description of the code book than a second index of the two indices.

18. The user equipment according to claim 10, wherein

the precoding matrix of the code book are accessed through the two indices.

19. A base station which communicates a user equipment, the base station comprising:

a memory configured to hold a codebook which is common to the user equipment and the base station;

wherein the codebook is set for each of a number of transmission rank;

a receiver configured to receive, from the user equipment, a channel state information, which the channel state information includes a channel quality information (CQI), rank indicator indicating transmission rank, and precoding matrix indicator;

a transmitter configured to transmit, to the user equipment, a data coded with a precoding matrix of the codebook selected based on two indices; and

wherein the codebook is for the CSI reporting.

20. The base station according to claim 19, wherein

the channel state information indicates a precoding matrix of the codebook.

21. The base station according to claim 19, wherein

the two indices are determined based on the channel state information.

22. The base station according to claim 19, wherein

the two indices are unique to the precoding matrix.

23. The base station according to claim 19, wherein

the codebook is a set of precoding matrix.

24. The base station according to claim 19, wherein

the codebook comprises a vector codebook.

25. The base station according to claim 19, wherein

the precoding matrix is determined by calculation.

26. The base station according to claim 19, wherein

a first index of the two indices provides a finer description of the codebook than a second index of the two indices.

27. The base station according to claim 19, wherein

the precoding matrix of the codebook are accessed through the two indices.

28. A method implemented in a user equipment which communicates a base station, the method comprising:

storing a codebook which is common to the user equipment and the base station;

wherein the codebook is set for each of a number of transmission rank;

transmitting, to the base station, a channel state information, which the channel state information includes a channel quality information (CQI), rank indicator indicating transmission rank, and a precoding matrix Indicator;

receiving, from the base station, a data coded with a precoding matrix of the codebook selected based on two indices; and

wherein the codebook is for the CSI reporting.

29. The method according to claim 28, wherein

the channel state information indicates a precoding matrix of the codebook.

30. The method according to claim 28, wherein

the two indices are determined based on the channel state Information.

31. The method according to claim 28, wherein

the two indices are unique to the precoding matrix.

32. The method according to claim 28, wherein

the code book is a set of precoding matrix.

33. The method according to claim 28, wherein

the codebook comprises a vector codebook.

34. The method according to claim 28, wherein

the precoding matrix is determined by calculation.

35. The method according to claim 28, wherein

a first index of the two indices provides a finer description of the codebook than a second Index of the two indices.

36. The method according to claim 28, wherein

the precoding matrix of the codebook are accessed through the two indices.

37. A method implemented in a base station which communicates a user equipment, the method comprising:

storing a codebook which is common to the user equipment and the base station;

wherein the code book is set for each of a number of transmission rank;

receiving, from the user equipment, a channel state information, which the channel state information includes a channel quality information (CQI), rank indicator indicating transmission rank, and precoding matrix indicator;

transmitting, to the user equipment, a data coded with a precoding matrix of the codebook selected based on two indices; and

wherein the codebook is for the CSI reporting.

38. The method according to claim 37, wherein

the channel state information indicates a precoding matrix of the code book.

39. The method according to claim 37, wherein

the two indices are determined based on the channel state information.

40. The method according to claim 37, wherein

the two indices are unique to the precoding matrix.

41. The method according to claim 37, wherein

the code book is a set of pre coding matrix.

42. The method according to claim 37, wherein

the codebook comprises a vector codebook.

43. The method according to claim 37, wherein

the precoding matrix is determined by calculation.

44. The method according to claim 37, wherein

a first index of the two indices provides a finer description of the code book than a second index of the two indices.

45. The method according to claim 37, wherein

the precoding matrix of the codebook are accessed through the two indices.