METHODS AND APPARATUS FOR INTERFERENCE CANCELLATION

• US 20110085520A1
• Filed: 11/08/2009
• Published: 04/14/2011
• Est. Priority Date: 01/17/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Black, Peter J., Jou, Yu-Cheun, Attar, Rashid A.
• Granted Patent: US 8,854,944 B2
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04B 1/7107 Subtractive interference cancellation

Abstract

Disclosed are methods and apparatus for interference cancellation in a wireless communication system. In particular, the disclosed methods and apparatus provide for interference cancellation in a wireless device, including extending linear interference cancellation techniques, such as quasi-linear interference cancellation (QLIC), in the wireless device to a first orthogonal set, which may be a first quasi orthogonal function (QOF) set for a cdma2000 system to cancel interference from that set upon another desired QOF set. QLIC may also be extended to cancellation of signals from non-intended base stations as well. Accordingly, the present methods and apparatus afford reduced interference through QLIC by canceling signals due to either undesired QOF sets or non-intended base stations, which in turn results in an increase in forward link capacity.

Claims

1. A method for interference cancellation in a wireless device, the method comprising:

determining at least one cancellation signal based on one or more signals received in the wireless device; and

canceling interference by at least one received interfering signal from at least one of a first quasi orthogonal function (QOF) set and at non-intended base station based on the determined at least one cancellation signal.

2. The method as defined in claim 1, further comprising:

determining a signal estimate for a desired signal using one of codes determined with a second QOF set or codes from an intended base station, wherein the signal estimate is based on at least the desired signal and the at least one cancellation signal.

3. The method as defined in claim 1, wherein determining the at least one cancellation signal is based on quasi-linear interference cancellation (QLIC) for at least one signal from at least the first QOF set.

4. The method as defined in claim 2, wherein signals based on the first QOF set and the second QOF set are present in a co-located sector.

5. The method as defined in claim 2, wherein the signal from the second QOF set is from a base station in an active set of the wireless device.

6. The method as defined in claim 1, wherein the at least one received interfering signal using codes determined with at least a first quasi orthogonal function (QOF) set is from one of a base station in one of an active set and a neighbor set of the wireless device.

7. The method as defined in claim 1, wherein the wireless device is configured to operate in a cdma2000 1x radio access technology.

8. The method as defined in claim 1, further comprising:

canceling interference by the at least one received interfering signal from the non-intended base station by canceling a pilot from the non-intended base station.

9. An apparatus for interference cancellation in a wireless device, the apparatus comprising:

at least one processor configured to;

determine at least one cancellation signal based on one or more signals received in the wireless device; and

cancel interference by at least one received interfering signal from at least one of a first quasi orthogonal function (QOF) set and a non-intended base station based on the determined at least one cancellation signal; and

a memory coupled to the at least one processor.

10. The apparatus as defined in claim 9, wherein the at least one processor is further configured to determine a signal estimate for a desired signal using one of codes determined with a second QOF set or codes from an intended base station, wherein the signal estimate is based on at least the desired signal and the at least one cancellation signal.

11. The apparatus as defined in claim 9, wherein the at least one processor is configured to determine the at least one cancellation signal is based on quasi-linear interference cancellation (QLIC) for at least one signal from at least the first QOF set.

12. The apparatus as defined in claim 10, wherein signals based on the first QOF set and the second QOF set are present in a co-located sector.

13. The apparatus as defined in claim 10, wherein the signal from the second QOF set is from a base station in an active set of the wireless device.

14. The apparatus as defined in claim 10, wherein the at least one received interfering signal using codes determined with at least a first quasi orthogonal function (QOF) set is from one of a base station in one of an active set and a neighbor set of the wireless device.

15. The apparatus as defined in claim 9, wherein the wireless device is configured to operate in a cdma2000 1x radio access technology.

16. The apparatus as defined in claim 9, wherein the at least one processor is further configured to cancel interference by the at least one received interfering signal from the non-intended base station by canceling a pilot from the non-intended base station.

17. An apparatus for interference cancellation in a wireless device, the apparatus comprising:

means for determining at least one cancellation signal based on one or more signals received in the wireless device; and

means for canceling interference by at least one received interfering signal from at least one of a first quasi orthogonal function (QOF) set and a non-intended base station based on the determined at least one cancellation signal.

18. The apparatus as defined in claim 17, further comprising:

means for determining a signal estimate for a desired signal using one of codes determined with a second QOF set or codes from an intended base station, wherein the signal estimate is based on at least the desired signal and the at least one cancellation signal.

19. The apparatus as defined in claim 17, wherein the means for determining at least one cancellation signal is configured to determine the at least one cancellation signal is based on quasi-linear interference cancellation (QLIC) for at least one signal from at least the first QOF set.

20. The apparatus as defined in claim 18, wherein signals based on the first QOF set and the second QOF set are present in a co-located sector.

21. The apparatus as defined in claim 18, wherein the signal from the second QOF set is from a base station in an active set of the wireless device.

22. The apparatus as defined in claim 17, wherein the at least one received interfering signal using codes determined with at least a first quasi orthogonal function (QOF) set is from one of a base station in one of an active set and a neighbor set of the wireless device.

23. The apparatus as defined in claim 17, wherein the wireless device is configured to operate in a cdma2000 1x radio access technology.

24. The apparatus as defined in claim 17, wherein the means for canceling interference by the at least one received interfering signal from the non-intended base station is further configured to cancel interference by including canceling a pilot from the non-intended base station.

25. A computer program product, comprising:

computer-readable medium comprising;

code for causing a computer to determine at least one cancellation signal based on one or more signals received a wireless device; and

code for causing a computer to cancel interference by at least one received interfering signal from at least one of a first quasi orthogonal function (QOF) set and a non-intended base station based on the determined at least one cancellation signal.

26. The computer program product as defined in claim 25, the computer-readable medium further comprising code for causing a computer to determine a signal estimate for a desired signal using one of codes determined with a second QOF set or codes from an intended base station, wherein the signal estimate is based on at least the desired signal and the at least one cancellation signal.

27. The computer program product as defined in claim 25, wherein the code for causing a computer to determine at least one cancellation signal further comprises code for causing a computer to determine the at least one cancellation signal based on quasi-linear interference cancellation (QLIC) for at least one signal from at least the first QOF set.

28. The computer program product as defined in claim 26, wherein signals based on the first QOF set and the second QOF set are present in a co-located sector.

29. The computer program product as defined in claim 26, wherein the signal from the second QOF set is from a base station in an active set of the wireless device.

30. The computer program product as defined in claim 25, wherein the at least one received interfering signal using codes determined with at least a first quasi orthogonal function (QOF) set is from one of a base station in one of an active set and a neighbor set of the wireless device.

31. The computer program product as defined in claim 25, wherein the wireless device is configured to operate in a cdma2000 1x radio access technology.

32. The computer program product as defined in claim 25, wherein code for causing a computer to cancel interference by the at least one received interfering signal from the non-intended base station includes code for causing a computer to cancel a pilot from the non-intended base station.