Methods and apparatus for controlling resource use in a wireless communications system

• US 8,331,965 B2
• Filed: 06/12/2009
• Issued: 12/11/2012
• Est. Priority Date: 06/12/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Richardson, Thomas
• Primary Examiner(s): Wendell, Andrew
• Application Number:
  US12/483,335
• Publication Number:
  US 20100317291A1
• Time in Patent Office: 1,278 Days
• Field of Search: 455/500, 455/501, 455/507, 455/63.1, 455/67.11, 455/67.13, 455/69, 455/296
• US Class Current: 455/501
• CPC Class Codes: H04W 74/0825 with collision detection
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals

Abstract

Methods and apparatus for detecting, controlling and/or mitigating interference are described. Various embodiments are well suited to wireless communications systems in which shared communications resources are used, e.g., in a peer to peer communications systems lacking centralized control. In some embodiments, a communications device receives signals on shared communications resource, evaluates its capability to decode a received signal, and conditionally transmits an interference signal, e.g., on the shared communications resource. The interference signal is intended to cause a device transmitting on the shared communications resource to switch to a different communications resource, e.g., in response to the interference signal, so that its transmitted signal can be successfully decoded. In at least one embodiment, the shared communications resource is a peer discovery air link resource associated with a peer discovery resource identifier.

Claims

1. A method of operating a first communications device, the method comprising:

receiving first and second signals from second and third communications devices, respectively, on a first shared communications resource being used by both said second and third communications devices;

determining that signal quality of the first and second signals is insufficient for reliable decoding;

estimating a received power level of the stronger one of the first and second signals;

determining if the estimated received power level exceeds a threshold power level; and

transmitting an interference signal, after it is determined that that the signal quality of the first and second signals is insufficient for reliable decoding and the estimated received power level exceeds the threshold power level, on said first shared communications resource, transmission of the interference signal following said determining and being contingent on said determining that the signal quality of the first and second signals is insufficient for reliable decoding.

2. The method of claim 1, wherein transmitting the interference signal includes transmitting said interference signal at a power level sufficient to be detected as a signal collision by at least one of said second and third devices.

3. The method of claim 1, further comprising:

receiving third and fourth signals from fourth and fifth communications devices, respectively, on a second shared communications resource being used by both said fourth and fifth communications devices;

estimating a second received power level of the stronger one of the third and fourth signals;

determining that signal quality of the third and fourth signals is insufficient for reliable decoding;

comparing the second estimated received power level to said threshold power level to determine if the second estimated received power level exceeds said threshold power level; and

upon determining that said second estimated received power level does not exceed said threshold power level deciding not to transmit a second interference signal on said second shared communications resource.

4. The method of claim 1, further comprising:

determining said threshold power level based on power received on at least one other shared communications resource.

5. The method of claim 1, wherein said first shared communications resource includes OFDM tone-symbols corresponding to multiple symbol time periods.

6. The method of claim 5, wherein said first shared communications resource is a peer discovery device communications channel including said OFDM tone-symbols.

7. A first communications device comprising:

means for receiving first and second signals from second and third communications devices, respectively, on a first shared communications resource being used by both said second and third communications devices;

means for determining that signal quality of the first and second signals is insufficient for reliable decoding;

means for estimating a received power level of the stronger one of the first and second signals;

means for determining if the estimated received power level exceeds a threshold power level; and

means for transmitting an interference signal, after it is determined that that the signal quality of the first and second signals is insufficient for reliable decoding and the estimated received power level exceeds the threshold power level, on said first shared communications resource, said interference signal being transmitted by said means for transmitting following said determining and being contingent on said determining that the signal quality of the first and second signals is insufficient for reliable decoding.

8. The first communications device of claim 7, wherein said means for transmitting an interference signal includes means for transmitting said interference signal at a power level sufficient to be detected as a signal collision by at least one of said second and third devices.

9. The first communications device of claim 7, further comprising:

means for receiving third and fourth signals from fourth and fifth communications devices, respectively, on a second shared communications resource being used by both said fourth and fifth communications devices;

means for estimating a second received power level of the stronger one of the third and fourth signals;

means for determining that signal quality of the third and fourth signals is insufficient for reliable decoding;

means for comparing the second estimated received power level to said threshold power level to determine if the second estimated received power level exceeds said threshold power level; and

means for deciding not to transmit a second interference signal on said second shared communications resource, upon said means for comparing determining that said second estimated received power level does not exceed said threshold power level.

10. The first communications device of claim 7, further comprising:

means for determining said threshold power level based on power received on at least one other shared communications resource.

11. The first communications device of claim 7, wherein said first shared communications resource includes OFDM tone-symbols corresponding to multiple symbol time periods.

12. The first communications device of claim 11, wherein said first shared communications resource is a peer discovery device communications channel including said OFDM tone-symbols.

13. A computer program product for use in a first communications device, the computer program product comprising:

a non-transitory computer readable medium comprising;

code for causing at least one computer to receive first and second signals from second and third communications devices, respectively, on a first shared communications resource being used by both said second and third communications devices;

code for causing said at least one computer to determine that signal quality of the first and second signals is insufficient for reliable decoding;

code for causing said at least one computer to estimate a received power level of the stronger one of the first and second signals;

code for causing said at least one computer to determine if the estimated received power level exceeds a threshold power level; and

code for causing said at least one computer to transmit an interference signal, after it is determined that that the signal quality of the first and second signals is insufficient for reliable decoding and the estimated received power level exceeds the threshold power level, on said first shared communications resource, transmission of the interference signal following said determining and being contingent on said determining that the signal quality of the first and second signals is insufficient for reliable decoding.

14. A first communications device comprising:

at least one processor configured to;

receive first and second signals from second and third communications devices, respectively, on a first shared communications resource being used by both said second and third communications devices;

determine that signal quality of the first and second signals is insufficient for reliable decoding;

estimate a received power level of the stronger one of the first and second signals;

determine if the estimated received power level exceeds a threshold power level; and

transmit an interference signal on said first shared communications resource, said processor being configured to transmit the interference signal following said determining that the signal quality of the first and second signals is insufficient for reliable decoding and that the estimated received power level exceeds the threshold power level; and

memory coupled to said at least one processor.

15. The first communications device of claim 14, wherein said at least one processor is further configured to:

transmit said interference signal at a power level sufficient to be detected as a signal collision by at least one of said second and third devices, as part of being configured to transmit the interference signal.

16. The first communications device of claim 14, wherein said at least one processor is further configured to:

receive third and fourth signals from fourth and fifth communications devices, respectively, on a second shared communications resource being used by both said fourth and fifth communications devices;

estimate a second received power level of the stronger one of the third and fourth signals;

determine that signal quality of the third and fourth signals is insufficient for reliable decoding;

compare the second estimated received power level to said threshold power level to determine if the second estimated received power level exceeds said threshold power level; and

decide not to transmit a second interference signal on said second shared communications resource, upon determining that said second estimated received power level does not exceed said threshold power level.

17. The first communications device of claim 14, wherein said at least one processor is further configured to:

determine said threshold power level based on power received on at least one other shared communications resource.