System and Method for Link Adaptation Overhead Reduction

• US 20080310400A1
• Filed: 12/28/2007
• Published: 12/18/2008
• Est. Priority Date: 06/15/2007
• Status: Active Grant

• Current Assignee: Blackberry Limited
• Original Assignee: Blackberry Limited
• Inventors: Suzuki, Takashi, Womack, James Earl, Cai, Zhijun, Young, Gordon
• Granted Patent: US 8,432,818 B2
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: H04L 1/0027 Scheduling of signalling, e.g. occurrence thereof
• CPC Class Codes: H04L 1/0029 Reduction of the amount of signalling, e.g. retention of useful signalling or differential signalling power control H04W52/04
• CPC Class Codes: H04L 1/0034 where the transmitter decides based on inferences, e.g. use of implicit signalling
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04W 28/0289 Congestion control load shedding arrangements in network planning H04W16/08; performing reselection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters

Abstract

Systems and methods of providing link adaptation information feedback are provided. A mobile device that receives packets generates link adaptation information based on incorrectly received packets. This can involve sending link adaptation information in association with NACKs (negative acknowledgements) generated by the mobile device. The network receives this link adaptation information and performs link adaptation accordingly.

Claims

1. A method in a mobile device comprising:

receiving packets;

transmitting fast MCS link adaptation information based on incorrectly received packets.

2. The method of claim 1 wherein receiving packets comprises receiving packets that are VoIP packets, constant rate packet, real-time packets or constant rate real-time packets.

3. The method of claim 1 wherein transmitting fast MCS link adaptation information based on incorrectly received packets comprises:

transmitting NACKs (negative acknowledgements; and

transmitting fast MCS link adaptation information in association with the NACKS.

4. The method of claim 3 wherein transmitting fast MCS link adaptation information in association with the NACKs comprises:

transmitting fast MCS link adaptation information for each NACK.

5. The method of claim 3 wherein transmitting fast MCS link adaptation information in association with the NACKs comprises:

transmitting fast MCS link adaptation information when the NACKs transmitted by the mobile device satisfy at least one other criteria.

6. The method of claim 5 wherein transmitting fast MCS link adaptation information when the NACKs transmitted by the mobile device satisfy at least one other criteria comprises:

the mobile device transmitting fast MCS link adaptation information when the transmitted NACKs include a number of transmitted NACKs within a sliding window that is greater than a predefined number.

7. The method of claim 1 wherein the fast MCS link adaptation comprises at least one of:

a CQI (channel quality indication);

a received signal value; and

an MCS decision made by the mobile device.

8. The method of claim 3 further comprising:

transmitting the fast MCS link adaptation information in combination with NACKs using code division modulation.

9. The method of claim 1 further comprising:

the mobile device transmitting slow MCS link adaptation information from time to time.

10. A method in a wireless network comprising:

transmitting packets;

receiving at the wireless network fast MCS link adaptation information based on transmitted packets that were incorrectly received;

based on the fast MCS link adaptation information, adjusting an MCS used to transmit the packets.

11. The method of claim 10 transmitting packets comprises transmitting packets that are VoIP packets, constant rate packet, real-time packets or constant rate real-time packets.

12. The method of claim 10 wherein receiving fast MCS link adaptation information based on transmitted packets that were incorrectly received comprises:

receiving NACKs (negative acknowledgements); and

receiving fast MCS link adaptation information in association with the NACKs.

13. The method of claim 12 wherein receiving fast MCS link adaptation information in association with the NACKs comprises:

receiving fast MCS link adaptation information for each NACK.

14. The method of claim 12 wherein receiving fast MCS link adaptation information in association with the NACKs comprises:

receiving fast MCS link adaptation information when NACKs transmitted by the mobile device satisfy at least one other criteria.

15. The method of claim 10 wherein the fast MCS link adaptation comprises at least one of:

a CQI (channel quality indication);

a received signal value; and

an MCS decision made by the mobile device.

16. The method of claim 12 further comprising:

receiving the fast MCS link adaptation information in combination with NACKs using code division modulation.

17. The method of claim 10 further comprising:

receiving slow MCS link adaptation information from time to time; and

making MCS decisions based on the slow MCS link adaptation.

18. The method of claim 12 further comprising:

processing received NACKs and/or ACKs received over a time window to make a slow MCS adaptation decision.

19. A mobile device comprising:

a wireless access radio configured to receive packets;

a fast link adaptation information generator configured to generate fast MCS link adaptation information based on incorrectly received packets, and to transmit the fast MCS link adaptation information using the wireless access radio.

20. A wireless network comprising:

a transmitter that transmits packets;

a receiver that receives fast MCS link adaptation information based on transmitted packets that were incorrectly received;

a fast link adaptation information processor that adjusts an MCS used to transmit the packets based on the fast MCS link adaptation information.