Method and system for rate selection algorithm to maximize throughput in closed loop multiple input multiple output (MIMO) wireless local area network (WLAN) system

• US 7,525,988 B2
• Filed: 02/18/2005
• Issued: 04/28/2009
• Est. Priority Date: 01/17/2005
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Kim, Joonsuk
• Primary Examiner(s): Shah; Chirag G
• Assistant Examiner(s): Thompson, Jr.; Otis L
• Application Number:
  US11/061,567
• Publication Number:
  US 20060159120A1
• Time in Patent Office: 1,530 Days
• Field of Search: None
• US Class Current: 370/465
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0068 by puncturing
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 47/25 with rate being modified by the source upon detecting a change of network conditions
• CPC Class Codes: H04L 67/61 taking into account QoS or priority requirements
• CPC Class Codes: H04L 69/14 Multichannel or multilink protocols
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Aspects of a method and system for rate selection algorithm to maximize throughput in closed loop multiple input multiple output (MIMO) wireless local area network (WLAN) system are provided and may comprise computing a maximum number of binary bits to be simultaneously transmitted via an RF channel based on signal quality. A modulation technique may be selected based on the computed maximum, communicating feedback information comprising the selected modulation technique. Subsequently transmitted data may be received via an RF channel which is modulated based on the feedback information. Another aspect of the method may comprise receiving feedback information comprising at least one of a selected modulation technique and coding rate via an RF channel, and transmitting subsequent data via said at least one of a plurality of RF channels which either modulated, or coded, based on the feedback information.

Claims

1. A method for communicating information in a communication system, the method comprising:

computing a maximum number of binary bits to be concurrently transmitted via at least one of a plurality of downlink RF channels based on one or more computed geometric mean signal quality values for said at least one of said plurality of downlink RF channels, wherein a plurality of signal quality values is computed for each of said plurality of downlink RF channels;

selecting at least one modulation technique based on said computed maximum number of binary bits;

communicating, via at least one of a plurality of uplink RF channels, feedback information comprising one or both of;

said selected said at least one modulation technique and said one or more computed geometric mean signal quality values; and

receiving, via said at least one of said plurality of downlink RF channels, subsequently transmitted data that utilizes a downlink modulation type, wherein said downlink modulation type is said selected at least one modulation technique and/or is based on said feedback information.

2. The method according to claim 1, comprising determining a plurality of modulation technique and coding rate combinations based on a plurality of signal to noise ratio values.

3. The method according to claim 2, comprising representing said plurality of modulation technique and coding rate combinations and said plurality of signal to noise ratio values in a lookup table.

4. The method according to claim 2, comprising selecting said at least one modulation technique and a corresponding coding rate from said plurality of modulation type and coding rate combinations based on one or more packet error rate values.

5. The method according to claim 4, comprising communicating said feedback information comprising said selected at least one modulation technique and said corresponding coding rate.

6. The method according to claim 1, comprising computing each of said one or more computed geometric mean signal quality values based on a multiplicative product of a plurality of signal to noise ratios, wherein each of said plurality of signal to noise ratios is observed in connection with a corresponding distinct frequency within a frequency bandwidth of said at least one of said plurality of downlink RF channels.

7. A system for communicating information in a communication system, the system comprising:

one or more circuits that enable computation of a maximum number of binary bits to be concurrently transmitted via at least one of a plurality of downlink RF channels based on one or more computed geometric mean signal quality values for said at least one of said plurality of downlink RF channels, wherein a plurality of signal quality values is computed for each of said plurality of downlink RF channels;

said one or more circuits enable selection of at least one modulation technique based on said computed maximum number of binary bits;

said one or more circuits enable communication, via at least one of a plurality of uplink RF channels, of feedback information comprising one or both of;

said selected said at least one modulation technique and said one or more computed geometric mean signal quality values; and

said one or more circuits enable reception, via said at least one of said plurality of downlink RF channels, of subsequently transmitted data that utilizes a downlink modulation type, wherein said downlink modulation type is said selected at least one modulation technique and/or is based on said feedback information.

8. The system according to claim 7, wherein said one or more circuits enable determination of a plurality of modulation technique and coding rate combinations based on a plurality of signal to noise ratio values.

9. The system according to claim 8, wherein said one or more circuits enable representation of said plurality of modulation technique and coding rate combinations and said plurality of signal to noise ratio values in a lookup table.

10. The system according to claim 8, wherein said one or more circuits enable selection of said at least one modulation technique and a corresponding coding rate from said plurality of modulation type and coding rate combinations based on one or more packet error rate values.

11. The system according to claim 10, wherein said one or more circuits enable communication of said feedback information comprising said selected at least one modulation technique and said corresponding coding rate.

12. The system according to claim 7, wherein said one or more circuits enable computation of each of said one or more geometric mean signal quality values based on a multiplicative product of a plurality of signal to noise ratios, wherein each of said plurality of signal to noise ratios is observed in connection with a corresponding distinct frequency within a frequency bandwidth of said at least one of said plurality of downlink RF channels.

13. A method for communicating information in a multiple input multiple output communication system, the method comprising:

receiving, via one or more uplink RF channels, feedback information comprising one or more geometric mean signal quality values;

selecting a modulation technique and/or coding rate based on each of said one or more geometric mean signal quality values; and

transmitting, via at least one of a plurality of downlink RF channels, subsequent data utilizing said selected one or more modulation techniques and/or coding rates, wherein each of said plurality of downlink RF channels enable computation of a plurality of signal quality values, and said computed plurality of signal quality values enable generation of one or more subsequently received geometric mean signal quality values.

14. The method according to claim 13, wherein said selected one or more modulation techniques and/or codinq rates is utilized for each distinct frequency within a frequency bandwidth for said at least one of said plurality of downlink RF channels.

15. The method according to claim 13, comprising selecting said one or more modulation techniques and/or coding rates based on at least one or more of:

a computed maximum number of binary bits to be concurrently transmitted via said at least one of said plurality of downlink RF channels, at least one packet error rate and at least one throughput rate.

16. The method according to claim 13, comprising determining a plurality of modulation technique and coding rate combinations based on one or more of a plurality of signal to noise ratio values, at least one packet error rate and at least one computed throughput rate.

17. The method according to claim 16, comprising selecting said modulation technique and/or coding rate from said plurality of modulation technique and coding rate combinations based on said one or more geometric mean signal quality values.

18. A system for communicating information in a multiple input multiple output communication system, the system comprising:

one or more circuits that enable reception, via one of one or more uplink RF channels, of feedback information comprising one or more geometric mean signal quality values;

said one or more circuits enable selection of a modulation technique and/or coding rate based on each of said one or more geometric mean signal quality values; and

said one or more circuits enable transmission, via a plurality of downlink RF channels, subsequent data utilizing said selected one or more modulation techniques and/or coding rates, wherein each of said plurality of downlink RF channels enable computation of a plurality of signal quality values, and said computed plurality of signal quality values enable generation of one or more subsequently received geometric mean signal quality values.

19. The system according to claim 18, wherein said selected one or more modulation techniques and/or coding rates is utilized for each distinct frequency within a frequency bandwidth for said at least one of said plurality of downlink RF channels.

20. The system according to claim 18, wherein said one or more circuits enable selection of said one or more modulation techniques and/or coding rates based on one or more of:

a computed maximum number of binary bits to be concurrently transmitted via said at least one of said plurality of downlink RF channels, at least one packet error rate and/or at least one throughput rate.

21. The system according to claim 18, wherein said one or more circuits enable determination of a plurality of modulation technique and coding rate combinations based on one or more of a plurality of signal to noise ratio values, at least one packet error rate and at least one computed throughput rate.

22. The system according to claim 21, wherein said one or more circuits enable selection of said modulation technique and/or coding rate from said plurality of modulation technique and coding rate combinations based on said one or more geometric mean signal quality values.