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

• US 8,270,432 B2
• Filed: 12/18/2008
• Issued: 09/18/2012
• 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): Thompson, Jr., Otis L
• Application Number:
  US12/338,895
• Publication Number:
  US 20090161641A1
• Time in Patent Office: 1,370 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, the method comprising:

in a wireless device operable to perform closed loop multiple-input-multiple-output (MIMO) communication;

determining a geometric mean signal-to-noise ratio (SNR) value for each of a plurality of downlink radio frequency (RF) channels based on a plurality of tones corresponding to each of the plurality of downlink RF channels;

selecting a modulation technique and a coding rate for each of the plurality of downlink RF channels based on the corresponding geometric mean SNR value; and

communicating, via one or more uplink RF channels, feedback information comprising the selected modulation technique and the selected coding rate for each of the plurality of downlink RF channels.

2. The method according to claim 1, wherein the selected modulation technique and the selected coding rate for a particular downlink RF channel are utilized for each distinct frequency within a frequency bandwidth corresponding to the particular downlink RF channel.

3. The method according to claim 1, comprising determining a plurality of modulation technique and coding rate combinations for a plurality of SNR values.

4. The method according to claim 3, comprising representing the plurality of modulation technique and coding rate combinations and the plurality of SNR values in a lookup table.

5. The method according to claim 3, comprising selecting the modulation technique and the coding rate for each of the plurality of downlink RF channels from the plurality of modulation type and coding rate combinations based on one or more packet error rate values.

6. The method according to claim 1, comprising receiving, via the plurality of downlink RF channels, subsequently transmitted data that is based on the communicated feedback information.

7. The method according to claim 1, comprising determining each geometric mean SNR value based on a multiplicative product of a plurality of SNR values, wherein each of the plurality of SNR values is observed in connection with a distinct frequency within a frequency bandwidth of the corresponding downlink RF channel.

8. A system for communicating information, the system comprising:

one or more circuits for use in a wireless device that is operable for closed loop multiple-input multiple-output (MIMO) communication, the one or more circuits being operable to;

determine a geometric mean signal-to-noise ratio (SNR) value for each of a plurality of downlink radio frequency (RF) channels based on a plurality of tones corresponding to each of the plurality of downlink RF channels;

select a modulation technique and a coding rate for each of the plurality of downlink RF channels based on the corresponding geometric mean SNR value; and

communicate, via one or more uplink RF channels, feedback information comprising the selected modulation technique and the selected coding rate for each of the plurality of downlink RF channels.

9. The system according to claim 8, wherein the selected modulation technique and the selected coding rate for a particular downlink RF channel are utilized for each distinct frequency within a frequency bandwidth corresponding to the particular downlink RF channel.

10. The system according to claim 8, wherein the one or more circuits are operable to determine a plurality of modulation technique and coding rate combinations for a plurality of SNR values.

11. The system according to claim 10, wherein the one or more circuits are operable to represent the plurality of modulation technique and coding rate combinations and the plurality of SNR values in a lookup table.

12. The system according to claim 10, wherein the one or more circuits are operable to select the modulation technique and the coding rate for each of the plurality of downlink RF channels from the plurality of modulation type and coding rate combinations based on one or more packet error rate values.

13. The system according to claim 8, wherein the one or more circuits are operable to receive, via the downlink RF channels, subsequently transmitted data that is based on the communicated feedback information.

14. The system according to claim 8, wherein the one or more circuits are operable to determine each geometric mean SNR value based on a multiplicative product of a plurality of SNR values, wherein each of the plurality of SNR values is observed in connection with a distinct frequency within a frequency bandwidth of the corresponding downlink RF channel.

15. A method for communicating information, the method comprising:

in a wireless device operable to perform closed loop multiple-input-multiple-output (MIMO) communication;

receiving a geometric mean signal-to-noise ratio (SNR) value for each of a plurality of downlink radio frequency (RF) channels based on a plurality of tones corresponding to each of the plurality of downlink RF channels;

selecting a modulation technique and a coding rate for each of the plurality of downlink RF channels based on the corresponding geometric mean SNR value; and

transmitting, via the plurality of downlink RF channels, data based on the selected modulation technique and the selected coding rate for each of the plurality of downlink RF channels.

16. The method according to claim 15, comprising selecting the modulation technique and the coding rate for each of the plurality of downlink RF channels based on one or more of a computed maximum number of binary bits to be concurrently transmitted via the plurality of downlink RF channels, one or more packet error rates, and one or more throughput rates.

17. The method according to claim 15, comprising determining a plurality of modulation technique and coding rate combinations based on one or more of a plurality of SNR values, one or more packet error rates, and one or more computed throughput rates.

18. The method according to claim 17, comprising selecting the modulation technique and the coding rate for each of the plurality of downlink RF channels from the plurality of modulation type and coding rate combinations.

19. A system for communicating information, the system comprising:

one or more circuits for use in a wireless device operable to perform closed loop multiple-input-multiple-output (MIMO) communication, the one or more circuits being operable to;

receive a geometric mean signal-to-noise ratio (SNR) value for each of a plurality of downlink radio frequency (RF) channels based on a plurality of tones corresponding to each of the plurality of downlink RF channels;

select a modulation technique and a coding rate for each of the plurality of downlink RF channels based on the corresponding geometric mean SNR value; and

transmit, via the plurality of downlink RF channels, data based on the selected modulation technique and the selected coding rate for each of the plurality of downlink RF channels.

20. The system according to claim 19, wherein the one or more circuits are operable to select the modulation technique and the coding rate for each of the plurality of downlink RF channels based on one or more of a computed maximum number of binary bits to be concurrently transmitted via the plurality of downlink RF channels, one or more packet error rates, and one or more throughput rates.

21. The system according to claim 19, wherein the one or more circuits are operable to determine a plurality of modulation technique and coding rate combinations based on one or more of a plurality of SNR values, one or more packet error rates, and one or more computed throughput rates.

22. The system according to claim 21, wherein the one or more circuits are operable to select the modulation technique and the coding rate for each of the plurality of downlink RF channels from the plurality of modulation type and coding rate combinations.