Communicating a feedback data structure containing information identifying coding to be applied on wirelessly communicated signaling

• US 8,929,245 B2
• Filed: 08/21/2013
• Issued: 01/06/2015
• Est. Priority Date: 02/28/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Sivanesan, Kathiravetpillai, Zhu, Peiying, Kim, Sang-Youb, Tee, Lai King, Xiao, Junfeng
• Primary Examiner(s): GHOWRWAL, OMAR J
• Application Number:
  US13/971,975
• Publication Number:
  US 20130336416A1
• Time in Patent Office: 503 Days
• Field of Search: None
• US Class Current: 370/252
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/063 Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 2025/03802 Signalling on the reverse channel
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04W 72/563 of the wireless resources

Abstract

To perform wireless communications in a closed loop multiple input, multiple output (MIMO) system, a feedback data structure is communicated over a wireless channel between a first wireless node and a second wireless node, where the feedback data structure contains indicators identifying coding to be applied by the second wireless node on signaling communicated between the second wireless node and the first wireless node, where the information in the feedback data structure is based on wireless channel conditions detected at the first wireless node. The indicators identify different codings to be used for different corresponding bands in the wireless channel.

Claims

1. A method for operating a first wireless node as part of a closed loop multiple-input multiple-output (MIMO) communication system including the first wireless node and a second wireless node, the method comprising:

estimating a channel matrix H of a wireless channel from the second wireless node to the first wireless node;

computing first indicators based on the channel matrix H, wherein the first indicators identify recommended coding for signaling to be transmitted from the second wireless node to the first wireless node, wherein the first indicators include;

a precoding matrix indicator (PMI) selected from a set of two or more available PMI values, and a rank mode indicator selected from a set of two or more available rank values, wherein said estimating and said computing are performed by digital circuitry, wherein said computing the first indicators includes;

computing an objective value for each precoding matrix in a predefined codebook, wherein rows of the codebook correspond to the two or more available PMI values, wherein columns of the codebook correspond to the two or more available rank values; and

selecting the first indicators based on a maximization of the objective value over the codebook;

transmitting a feedback data structure over the wireless channel from the first wireless node and to the second wireless node, wherein the feedback data structure includes the first indicators, wherein said transmitting is performed by a wireless interface.

2. The method of claim 1, wherein the feedback data structure includes one or more indicators for each frequency band in a plurality of frequency bands, wherein, for a first of the frequency bands, the one or more corresponding indicators include the first indicators.

3. The method of claim 2, wherein, for each of the frequency bands, the one or more corresponding indicators include:

a corresponding band-specific PMI value; and

a corresponding band-specific rank mode indicator.

4. The method of claim 1, wherein the objective value is a value representing channel capacity.

5. The method of claim 1, wherein the set of two or more available rank values includes rank one and rank two.

28. The method of claim 1, wherein the predefined codebook is stored in the first wireless node, wherein the predefined codebook is also stored in the second wireless node.

29. The method of claim 1, wherein the first indicators also include a channel quality indicator (CQI).

6. A method for operating a first wireless node as part of a closed loop multiple-input multiple-output (MIMO) communication system including the first wireless node and a second wireless node, the method comprising:

receiving a feedback data structure that is transmitted over a wireless medium by the second wireless node, wherein the feedback data structure contains first indicators, wherein said receiving is performed by a wireless interface;

operating, by digital circuitry, on signal data based on coding recommended by the first indicators in order to obtain transmit signals, wherein the first indicators include a precoding matrix indicator (PMI) and a rank mode indicator;

transmitting, by the wireless interface, the transmit signals to the second wireless node through the wireless medium;

wherein the first indicators have been determined based on an estimated channel matrix H, wherein the first indicators have been determined at the second wireless node by;

computing an objective value for each precoding matrix in a predefined codebook, wherein rows of the codebook correspond to two or more available PMI values, wherein columns of the codebook correspond to two or more available rank values; and

selecting the first indicators based on a maximization of the objective value over the codebook.

7. The method of claim 6, wherein the feedback data structure includes one or more indicators for each frequency band in a plurality of frequency bands, wherein, for a first of the frequency bands, said one or more corresponding indicators include the first indicators.

8. The method of claim 7, wherein, for each of the frequency bands, the one or more corresponding indicators include:

a corresponding band-specific PMI value; and

a corresponding band-specific rank mode indicator.

9. The method of claim 6, wherein the objective value is channel capacity.

10. The method of claim 6, wherein the set of two or more available rank values includes rank one and rank two.

11. The method of claim 6, wherein the one or more first indicators include the precoding matrix indicator, wherein the precoding matrix indicator and the rank mode indicator are used by the first wireless node to access a precoding matrix from the predefined codebook, wherein the precoding matrix is used by the first wireless node to precode one or more layers of the signal data to obtain the transmit signals, wherein the transmit signals are transmitted via respective antennas of the first wireless node.

30. The method of claim 6, wherein the predefined codebook is stored in the first wireless node, wherein the predefined codebook is also stored in the second wireless node.

31. The method of claim 6, wherein the first indicators also include a channel quality indicator (CQI).

12. A first wireless node for operating as part of a closed loop multiple-input multiple-output (MIMO) communication system including the first wireless node and a second wireless node, the first wireless node comprising:

digital circuitry configured to;

estimate a channel matrix H of a wireless channel from the second wireless node to the first wireless node; and

compute first indicators based on the channel matrix H, wherein the first indicators identify recommended coding for signaling to be transmitted from the second wireless node to the first wireless node, wherein the first indicators include;

a precoding matrix indicator (PMI) selected from a set of two or more available PMI values, and a rank mode indicator selected from a set of two or more available rank values, wherein said computing the first indicators includes;

computing an objective value for each precoding matrix in a predefined codebook, wherein rows of the codebook correspond to the two or more available PMI values wherein columns of the codebook correspond to the two or more available rank values; and

selecting the first indicators based on a maximization of the objective value over the codebook;

a wireless interface configured to transmit a feedback data structure over the wireless channel from the first wireless node and to the second wireless node, wherein the feedback data structure includes the first indicators, wherein said transmitting is performed by a wireless interface.

13. The first wireless node of claim 12, wherein the feedback data structure includes one or more indicators for each frequency band in a plurality of frequency bands, wherein, for a first of the frequency bands, the one or more corresponding indicators include the first indicators.

14. The first wireless node of claim 13, wherein, for each of the frequency bands, the one or more corresponding indicators include:

a corresponding band-specific PMI value; and

a corresponding band-specific rank mode indicator.

15. The first wireless node of claim 12, wherein the objective value is a value representing channel capacity.

16. A first wireless node for operating as part of a closed loop multiple-input multiple-output (MIMO) communication system including the first wireless node and a second wireless node, the first wireless node comprising:

digital circuitry configured to;

receive a feedback data structure that is transmitted over a wireless medium by the second wireless node, wherein the feedback data structure contains first indicators;

operate on signal data based on coding recommended by the first indicators in order to obtain transmit signals, wherein the first indicators include;

a precoding matrix indicator (PMI) and a rank mode indicator;

a wireless interface configured to transmit the transmit signals to the second wireless node through the wireless medium;

wherein the first indicators have been determined based on an estimated channel matrix H, wherein the first indicators have been determined at the second wireless node by;

computing an objective value for each precoding matrix in a predefined codebook, wherein rows of the codebook correspond to two or more available PMI values, wherein columns of the codebook correspond to two or more available rank values; and

selecting the first indicators based on a maximization of the objective value over the codebook.

17. The first wireless node of claim 16, wherein the feedback data structure includes one or more indicators for each frequency band in a plurality of frequency bands, wherein, for a first of the frequency bands, said one or more corresponding indicators include the first indicators.

18. The first wireless node of claim 17, wherein, for each of the frequency bands, the one or more corresponding indicators include:

a corresponding band-specific PMI value; and

a corresponding band-specific rank mode indicator.

19. The first wireless node of claim 16, wherein the objective value is channel capacity.

32. The first wireless node of claim 16, wherein the predefined codebook is stored in the first wireless node, wherein the predefined codebook is also stored in the second wireless node.

20. A non-transitory memory medium for operating a first wireless node as part of a closed loop multiple-input multiple-output (MIMO) communication system including the first wireless node and a second wireless node, wherein the memory medium stores program instructions, wherein the program instructions, when executed by a processor, cause the processor to:

estimate a channel matrix H of a wireless channel from the second wireless node to the first wireless node;

compute first indicators based on the channel matrix H, wherein the first indicators identify recommended coding for signaling to be transmitted from the second wireless node to the first wireless node, wherein the first indicators include;

a precoding matrix indicator (PMI) selected from a set of two or more available PMI values, and a rank mode indicator selected from a set of two or more available rank values, wherein said estimating and said computing are performed by digital circuitry, wherein said computing the first indicators includes;

computing an objective value for each precoding matrix in a predefined codebook, wherein rows of the codebook correspond to the two or more available PMI values, wherein columns of the codebook correspond to the two or more available rank values; and

selecting the first indicators based on a maximization of the objective value over the codebook.

21. The memory medium of claim 20, wherein the feedback data structure includes one or more indicators for each frequency band in a plurality of frequency bands, wherein, for a first of the frequency bands, the one or more corresponding indicators include the first indicators.

22. The memory medium of claim 21, wherein, for each of the frequency bands, the one or more corresponding indicators include:

a corresponding band-specific PMI value; and

a corresponding band-specific rank mode indicator.

23. The memory medium of claim 20, wherein the objective value is a value representing channel capacity.

24. A non-transitory memory medium for operating a first wireless node as part of a closed loop multiple-input multiple-output (MIMO) communication system including the first wireless node and a second wireless node, wherein the memory medium stores program instructions, wherein the program instructions, when executed b a processor, cause the processor to:

receive a feedback data structure that is transmitted over a wireless medium by the second wireless node, wherein the feedback data structure contains first indicators;

operating on signal data based on coding recommended by the first indicators in order to obtain transmit signals, wherein the first indicators include;

a precoding matrix indicator (PMI) and a rank mode indicator; and

transmit the transmit signals to the second wireless node through the wireless medium;

wherein the first indicators have been determined based on an estimated channel matrix H, wherein the first indicators have been determined at the second wireless node by;

computing an objective value for each precoding matrix in a predefined codebook, wherein rows of the codebook correspond to two or more available PMI values, wherein columns of the codebook correspond to two or more available rank values; and

selecting the first indicators based on a maximization of the objective value over the codebook.

25. The memory medium of claim 24, wherein the feedback data structure includes one or more indicators for each frequency band in a plurality of frequency bands, wherein, for a first of the frequency bands, said one or more corresponding indicators include the first indicators.

26. The memory medium of claim 25, wherein, for each of the frequency bands, the one or more corresponding indicators include:

a corresponding band-specific PMI value; and

a corresponding band-specific rank mode indicator.

27. The memory medium of claim 24, wherein the objective value is channel capacity.