MULTIPLE OTHER SECTOR INFORMATION COMBINING FOR POWER CONTROL IN A WIRELESS COMMUNICATION SYSTEM

• US 20100069107A1
• Filed: 11/19/2009
• Published: 03/18/2010
• Est. Priority Date: 03/15/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sutivong, Arak, Mese, Murat
• Granted Patent: US 8,761,080 B2
• Time in Patent Office: Days
• US Class Current: 455/504
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/201 Frame classification, e.g. bad, good or erased frame indication per se H04L1/0082
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

Techniques for adjusting transmit power to mitigate both intra-sector interference to a serving base station and inter-sector interference to neighbor base stations are described. This may be done by combining interference information from multiple base stations.

Claims

1. A method of performing power control at a wireless terminal in a wireless communication system, the method comprising:

obtaining, for at least two sectors, an indication of interference observed by the sector, each sector being a neighbor sector not designated to receive a data transmission sent by the wireless terminal or a serving sector designated to receive the data transmission sent by the wireless terminal;

combining each indication of interference received from the at least two sectors according to a weighting scheme based on a channel gain relationship for each sector with respect to a serving sector; and

adjusting transmit power for the data transmission based on the combined indications.

2. The method of claim 1, wherein the indication comprises a first bit that indicates whether the interference observed by the sector is above or below a first interference threshold.

3. The method of claim 2, wherein the indication further comprises a second bit that indicates whether the interference observed by the sector exceeds a second interference threshold that is higher than the first interference threshold.

4. The method of claim 1, wherein the serving sector comprises a reverse link serving sector.

5. The method of claim 1, further comprising determining a threshold value for each indication and wherein weighting comprises weighting each threshold value according to the channel gain relationship.

6. The method of claim 1, wherein channel gains for each of the at least two sectors and the serving sectors are estimated based on pilots received from the sectors, respectively.

7. The method of claim 1, wherein adjusting the transmit power comprises adjusting based on the combined indication and a probability.

8. The method of claim 7, further comprising determining the probability for adjusting the transmit power upward or downward based on the channel gain relationships for each of the at least two sectors.

9. The method of claim 8, wherein the probability is determined further based on a current level of the transmit power for the data transmission.

10. The method of claim 8, wherein the transmit power is adjusted in a fixed-size step and in accordance with the determined probability.

11. The method of claim 1, further comprising determining a step size for adjusting the transmit power based on the estimated channel gain relationships and wherein adjusting comprises adjusting based on the combined indications and the step size.

12. The method of claim 11, wherein the step size is determined further based on a current level of the transmit power for the data transmission.

13. An apparatus operable to perform power control at a wireless terminal in a wireless communication system, comprising:

a processor configured to obtain, for at least two sectors, an indication of interference observed by the sector, each sector being a neighbor sector not designated to receive a data transmission sent by the wireless terminal or a serving sector designated to receive the data transmission sent by the wireless terminal, to combine each indication of interference received from the at least two sectors according to a weighting scheme based on a channel gain relationship for each sector with respect to a serving sector, and to adjust a transmit power for data transmission based on the combined indication of interference received from the at least two sectors; and

a memory coupled with the processor.

14. The apparatus of claim 13, wherein the indication comprises a first bit that indicates whether the interference observed by the sector is above or below a first interference threshold.

15. The apparatus of claim 14, wherein the indication further comprises a second bit that indicates whether the interference observed by the sector exceeds a second interference threshold that is higher than the first interference threshold.

16. The apparatus of claim 13, wherein the serving sector comprise a reverse link serving sector.

17. The apparatus of claim 13, wherein the processor is configured to determine a threshold value for each indication and weight each threshold value according to the channel gain relationship.

18. The apparatus of claim 13, wherein the processor is configured to adjust the transmit power based on the combined indication and a probability.

19. The apparatus of claim 18, wherein the processor is configured to determine the probability, for adjusting the transmit power upward or downward, based on the channel gain relationships for each of the at least two sectors.

20. The apparatus of claim 19, wherein the processor is configured to determine the probability based on a current level of the transmit power for the data transmission.

21. The apparatus of claim 19, wherein the processor is configured to adjust the transmit power in a fixed-size step and in accordance with the determined probability.

22. The apparatus of claim 13, wherein the processor is configured to determine a step size and to adjust based on the combined indications and the step size.

23. The apparatus of claim 22, wherein the processor is configured to determine the step size based on a current level of the transmit power for the data transmission.

24. An apparatus operable to perform power control at a wireless terminal in a wireless communication system, comprising:

means for obtaining, for at least two sectors, an indication of interference observed by the sector, each sector being a neighbor sector not designated to receive a data transmission sent by the wireless terminal or a serving sector designated to receive the data transmission sent by the wireless terminal;

means for combining each indication of interference received from the at least two sectors according to a weighting scheme based on a channel gain relationship for each sector with respect to a serving sector; and

means for adjusting transmit power for the data transmission based on the combined indications.

25. The apparatus of claim 24, wherein the indication comprises a first bit that indicates whether the interference observed by the sector is above or below a first interference threshold.

26. The apparatus of claim 25, wherein the indication further comprises a second bit that indicates whether the interference observed by the sector exceeds a second interference threshold that is higher than the first interference threshold.

27. The apparatus of claim 24, further comprises means for determining a threshold value for each indication and wherein the means for weighting comprises means for weighting each threshold value according to the channel gain relationship.

28. The apparatus of claim 24, further comprising means for estimating channel gains based on pilots received.

29. The apparatus of claim 24, wherein the means for adjusting the transmit power comprises means for adjusting based on the combined indication and a probability.

30. The apparatus of claim 24, wherein the means for adjusting the transmit power comprises means for determining a step size for adjusting the transmit power based on the estimated channel gain relationships and adjusting based on the combined indications and the step size.

31. A computer readable storage medium comprising code, which, when executed by a processor, direct the processor to perform power control at a wireless terminal in a wireless communication system, the computer readable storage medium comprising:

code for obtaining, for at least two sectors, an indication of interference observed by the sector, each sector being a neighbor sector not designated to receive a data transmission sent by the wireless terminal or a serving sector designated to receive the data transmission sent by the wireless terminal;

code for combining each indication of interference received from the at least two sectors according to a weighting scheme based on a channel gain relationship for each sector with respect to a serving sector; and

code for adjusting transmit power for the data transmission based on the combined indications.

32. The computer readable storage medium of claim 31, wherein the indication comprises a first bit that indicates whether the interference observed by the sector is above or below a first interference threshold.

33. The computer readable storage medium of claim 32, wherein the indication further comprises a second bit that indicates whether the interference observed by the sector exceeds a second interference threshold that is higher than the first interference threshold.

34. The computer readable storage medium of claim 31, further comprising code for determining a threshold value for each indication and wherein the code for weighting comprises code for weighting each threshold value according to the channel gain relationship.

35. The computer readable storage medium of claim 31, further comprising code for estimating channel gains based on pilots received.

36. The computer readable storage medium of claim 31, wherein the code for adjusting the transmit power comprises code for adjusting based on the combined indication and a probability.

37. The computer readable storage medium of claim 31, wherein the code for adjusting the transmit power comprises code for determining a step size for adjusting the transmit power based on the estimated channel gain relationships and adjusting based on the combined indications and the step size.