Interference control in a wireless communication system

• US 20060209721A1
• Filed: 06/21/2005
• Published: 09/21/2006
• Est. Priority Date: 03/15/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sutivong, Arak, Julian, David Jonathan, Mese, Murat
• Granted Patent: US 8,942,639 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04B 17/10 of transmitters
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04W 28/24 Negotiating SLA [Service Level Agreement]; Negotiating QoS [Quality of Service]
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]
• CPC Class Codes: H04W 52/247 where the output power of a terminal is based on a path parameter sent by another terminal
• CPC Class Codes: H04W 52/265 taking into account the quality of service QoS
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 92/20 between access points

Abstract

For interference control, a sector m estimates interference observed from terminals in neighbor sectors and obtains an interference estimate. Sector m may generate an over-the-air (OTA) other-sector interference (OSI) report and/or an inter-sector (IS) OSI report based on the interference estimate. Sector m may broadcast the OTA OSI report to the terminals in the neighbor sectors. These terminals may adjust their transmit powers based on the OTA OSI report. Sector m may send the IS OSI report to the neighbor sectors, recieve IS OSI reports from the neighbor sectors, and regulate data transmissions for terminals in sector m based on the received IS OSI reports. Sector m may control admission of terminals to sector m, de-assign admitted terminals, schedule terminals in sector m in a manner to reduce interference to the neighbor sectors, and/or assign the terminals in sector m with traffic channels that cause less interference to the neighbor sectors.

Claims

1. An apparatus comprising:

a receiver unit operative to receive at least one interference report from at least one neighbor sector, wherein an interference report for each neighbor sector indicates an amount of interference observed by the neighbor sector due to transmissions from terminals in other sectors; and

a controller operative to regulate data transmissions for terminals in a sector based on the at least one interference report from the at least one neighbor sector.

2. The apparatus of claim 1, wherein the interference report for each neighbor sector indicates whether the neighbor sector observes excessive interference greater than a predetermined threshold.

3. The apparatus of claim 1, wherein the controller is operative to control admission of terminals to the sector based on the at least one interference report from the at least one neighbor sector.

4. The apparatus of claim 3, wherein the controller is operative to control admission of terminals to the sector further based on user priority class, quality of service (QoS) class, or a combination thereof.

5. The apparatus of claim 1, wherein the controller is operative to deny access to the sector or to de-assign terminals already granted access to the sector if any one of the at least one neighbor sector observes excessive interference.

6. The apparatus of claim 1, wherein the controller is operative to control loading of the sector based on the at least one interference report from the at least one neighbor sector.

7. The apparatus of claim 1, wherein the controller is operative to schedule the terminals in the sector for data transmission based on the at least one interference report from the at least one neighbor sector.

8. The apparatus of claim 1, wherein the controller is operative to reduce data rate for at least one of the terminals in the sector if any one of the at least one neighbor sector observes excessive interference.

9. The apparatus of claim 1, wherein the controller is operative to assign traffic channels to the terminals in the sector based on the at least one interference report from the at least one neighbor sector.

10. The apparatus of claim 1, further comprising:

a transmitter unit operative to broadcast the at least one interference report from the at least one neighbor sector to the terminals in the sector.

11. An apparatus comprising:

means for receiving at least one interference report from at least one neighbor sector, wherein an interference report for each neighbor sector indicates an amount of interference observed by the neighbor sector due to transmissions from terminals in other sectors; and

means for regulating data transmissions for terminals in a sector based on the at least one interference report from the at least one neighbor sector.

12. The apparatus of claim 11, wherein the means for regulating the data transmissions for the terminals in the sector comprises

means for controlling admission of terminals to the sector based on the at least one interference report from the at least one neighbor sector.

13. The apparatus of claim 11, wherein the means for regulating the data transmissions for the terminals in the sector comprises

means for scheduling the terminals in the sector for data transmission based on the at least one interference report from the at least one neighbor sector.

14. The apparatus of claim 11, wherein the means for regulating the data transmissions for the terminals in the sector comprises

means for assigning traffic channels to the terminals in the sector based on the at least one interference report from the at least one neighbor sector.

15. A method of controlling interference in a communication system, comprising:

receiving at least one interference report from at least one neighbor sector, wherein an interference report for each neighbor sector indicates an amount of interference observed by the neighbor sector due to transmissions from terminals in other sectors; and

regulating data transmissions for terminals in a sector based on the at least one interference report from the at least one neighbor sector.

16. The method of claim 15, wherein the regulating the data transmissions for the terminals in the sector comprises

controlling admission of terminals to the sector based on the at least one interference report from the at least one neighbor sector.

17. The method of claim 15, wherein the regulating the data transmissions for the terminals in the sector comprises

scheduling the terminals in the sector for data transmission based on the at least one interference report from the at least one neighbor sector.

18. The method of claim 15, wherein the regulating the data transmissions for the terminals in the sector comprises

assigning traffic channels to the terminals in the sector based on the at least one interference report from the at least one neighbor sector.

19. An apparatus comprising:

a processor operative to estimate interference observed by a sector due to transmissions from terminals in neighbor sectors and to provide an interference estimate; and

a controller operative to generate an interference report based on the interference estimate, wherein the interference report indicates one of multiple possible levels of interference observed by the sector.

20. The apparatus of claim 19, wherein the interference report conveys the interference observed by the sector relative to at least two thresholds.

21. The apparatus of claim 19, wherein the interference report indicates whether the interference observed by the sector is below a first threshold, is between the first threshold and a second threshold, or exceeds the second threshold.

22. The apparatus of claim 19, further comprising:

a transmitter unit operative to broadcast the interference report to the terminals in the neighbor sectors.

23. The apparatus of claim 19, wherein the controller is operative to generate a second interference report based on the interference estimate, and wherein the second interference report comprises more detailed information for the interference observed by the sector than the interference report.

24. The apparatus of claim 23, wherein the controller is operative to send the second interference report to at least one of the neighbor sectors.

25. The apparatus of claim 23, wherein the controller is operative to generate the second interference report if the interference estimate is above a predetermined threshold or if at least one of the neighbor sectors requests for the second interference report.

26. An apparatus comprising:

a communication unit operative to receive at least one interference report from at least one neighbor sector, wherein an interference report for each neighbor sector indicates one of multiple possible levels of interference observed by the neighbor sector; and

a controller operative to adjust transmit power based on the at least one interference report.

27. The apparatus of claim 26, wherein the interference report for each neighbor sector indicates whether the neighbor sector observes excessive interference greater than a predetermined threshold.

28. The apparatus of claim 26, wherein the controller is operative to adjust the transmit power by different amounts for different levels of interference observed by the at least one neighbor sector.

29. The apparatus of claim 26, wherein the controller is operative to adjust the transmit power at different rates for different levels of interference observed by the at least one neighbor sector.

30. The apparatus of claim 26, wherein the controller is operative to determine a rate of adjustment for the transmit power based on a user priority class or a quality of service (QoS) class and to adjust the transmit power at the determined rate.

31. The apparatus of claim 26, wherein the controller is operative to identify a strongest neighbor sector among the at least one neighbor sector and to adjust the transmit power based on an interference report received from the strongest neighbor sector.

32. The apparatus of claim 26, wherein the controller is operative to adjust the transmit power further based on interference reports received previously from the at least one neighbor sector.

33. The apparatus of claim 26, wherein the controller is operative to selectively apply a low transmit power limit to the transmit power based on the at least one interference report from the at least one neighbor sector.

34. An apparatus comprising:

means for receiving at least one interference report from at least one neighbor sector, wherein an interference report for each neighbor sector indicates one of multiple possible levels of interference observed by the neighbor sector; and

means for adjusting transmit power based on the at least one interference report.

35. The apparatus of claim 34, wherein the means for adjusting the transmit power comprises

means for adjusting the transmit power by different amounts for different levels of interference observed by the at least one neighbor sector.

36. The apparatus of claim 34, wherein the means for adjusting the transmit power comprises

means for adjusting the transmit power at different rates for different levels of interference observed by the at least one neighbor sector.

37. The apparatus of claim 34, further comprising:

means for identifying a strongest neighbor sector among the at least one neighbor sector, and wherein the means for adjusting the transmit power comprises means for adjusting the transmit power based on an interference report received from the strongest neighbor sector.

38. A method of controlling interference in a communication system, comprising:

receiving at least one interference report from at least one neighbor sector, wherein an interference report for each neighbor sector indicates one of multiple possible levels of interference observed by the neighbor sector; and

adjusting transmit power based on the at least one interference report.

39. The method of claim 38, wherein the adjusting the transmit power comprises

adjusting the transmit power by different amounts for different levels of interference observed by the at least one neighbor sector.

40. The method of claim 38, wherein the adjusting the transmit power comprises

adjusting the transmit power at different rates for different levels of interference observed by the at least one neighbor sector.

41. The method of claim 38, further comprising:

identifying a strongest neighbor sector among the at least one neighbor sector, and wherein the adjusting the transmit power comprises adjusting the transmit power based on an interference report received from the strongest neighbor sector.