Rate adaptation in wireless systems

• US 8,693,331 B1
• Filed: 01/03/2011
• Issued: 04/08/2014
• Est. Priority Date: 08/12/2003
• Status: Expired due to Fees

• Current Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Sampath, Hemanth, Narasimhan, Ravi
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Hom, Shick
• Application Number:
  US12/983,825
• Time in Patent Office: 1,191 Days
• Field of Search: None
• US Class Current: 370/232
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

Systems and techniques for rate adaptation in wireless communication systems are described. A described technique includes generating a transmission packet parameter associated with packets transmitted by a device at a first data rate; generating a reception packet parameter associated with packets received by the device; determining a second data rate based on the transmission packet parameter and the reception packet parameter; and transmitting future packets at the second data rate.

Claims

1. A method comprising:

generating a transmission packet parameter associated with packets transmitted by a device at a first data rate that is selected from a plurality of data rates;

generating a reception packet parameter associated with packets received by the device;

generating confidence values for the plurality of data rates using information comprising the transmission packet parameter and the reception packet parameter;

determining, from the plurality of data rates, a second data rate based on the transmission packet parameter and the reception packet parameter, wherein determining the second data rate is performed based on at least a portion of the confidence values; and

transmitting future packets at the second data rate.

2. The method of claim 1, wherein generating the confidence values comprises:

determining an average value associated with the reception packet parameter;

determining a calibration value associated with the transmission packet parameter, the calibration value determined to refine the average value; and

determining a confidence value based on the average value and the calibration value.

3. The method of claim 2, wherein determining the second data rate includes selecting as the second data rate a highest data rate associated with a lowest positive confidence value.

4. The method of claim 3, further comprising:

monitoring a number of unsuccessful packets transmitted at the second data rate; and

adjusting, based on the monitored number, the second data rate to a third data rate at which the future packets are to be transmitted, the third data rate being lower than the second data rate.

5. The method of claim 1, further comprising:

identifying a nominal signal quality parameter from a nominal table containing a plurality of signal quality parameters including the reception packet parameter, each of the plurality of signal quality parameters having a different value and corresponding to a different data rate supported by a channel through which packets are transmitted or received,

wherein determining the second data rate is performed based on the transmission packet parameter, the reception packet parameter, and the nominal signal quality parameter.

6. The method of claim 1, further comprising:

identifying one or more packets that are transmitted at the second data rate unsuccessfully;

determining a new data rate for each of the one or more identified packets that is to be retransmitted, the new data rate being different from the first data rate and the second data rate.

7. A device comprising:

a first section configured to transmit packets at a first data rate and to generate a transmission packet parameter associated with the transmitted packets;

a second section configured to receive packets and to generate a reception packet parameter associated with the received packets; and

a rate selector to determine a second data rate from a plurality of data rates including the first data rate based on the transmission packet parameter and the reception packet parameter, the second data rate to be used by the first section for transmitting future packets, wherein the rate selector is configured to generate a confidence value for each of the plurality of data rates using information comprising the transmission packet parameter and the reception packet parameter.

8. The device of claim 7, wherein the rate selector is configured to:

identify a nominal signal quality parameter from a nominal table containing a plurality of signal quality parameters including the reception packet parameter, each of the plurality of signal quality parameters having a different value and corresponding to a different data rate supported by a channel through which packets are transmitted or received; and

determine the second data rate based on the transmission packet parameter, the reception packet parameter, and the nominal signal quality parameter.

9. The device of claim 7, wherein the rate selector is configured to:

identify one or more packets that are transmitted at the second data rate unsuccessfully; and

determine a new data rate for each of the one or more identified packets that is to be retransmitted, the new data rate being different from the first data rate and the second data rate.

10. The device of claim 9, wherein the rate selector is configured to reduce the new data rate if the one or more identified packets transmitted at the new data rate fail to be transmitted successfully.

11. The device of claim 9, wherein the rate selector is configured to determine the new data rate based at least in part on a number of times the one or more identified packets have been retransmitted.

12. The device of claim 9, wherein the rate selector is configured to:

adjust the transmission packet parameter by a first predetermined value when a number of successive successful transmissions of the one or more packets at the second data rate exceeds a first predetermined threshold; and

adjust the transmission packet parameter by a second predetermined value when a number of successive unsuccessful transmissions of the one or more packets at the second data rate exceeds a second predetermined threshold.

13. The device of claim 7, wherein:

the transmission packet parameter includes a retry counter parameter; and

the rate selector is configured to increment the retry counter parameter in response to a packet retransmission due to an unsuccessful transmission.

14. The device of claim 13, wherein the rate selector is configured to determine the second data rate based on the retry counter parameter.

15. The device of claim 7, wherein the rate selector is configured to determine an average value associated with the reception packet parameter, and a calibration value associated with the transmission packet parameter, the calibration value determined to refine the average value, and wherein at least one of the confidence values are based on the average value and the calibration value.

16. The device of claim 7, wherein the rate selector is configured to:

select a highest data rate associated with a lowest positive confidence value as the second data rate.

17. The device of claim 16, further comprising a processor configured to:

monitor a number of unsuccessful packets transmitted at the second data rate; and

adjust, based on the monitored number, the second data rate to a third data rate at which the future packets are to be transmitted, the third data rate lower than the second data rate.