METHOD AND APPARATUS FOR MITIGATING INTERFERENCE IN FEMTOCELL DEPLOYMENTS

• US 20110319088A1
• Filed: 06/28/2011
• Published: 12/29/2011
• Est. Priority Date: 06/29/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: ZHOU, Yan, MESHKATI, Farhad, CHANDE, Vinay, YAVUZ, Mehmet
• Granted Patent: US 8,676,216 B2
• Time in Patent Office: Days
• US Class Current: 455/442
• 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 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Methods and apparatuses are provided for determining one or more parameters of an access point that can be set or adjusted to mitigate interference to other access points. A rise-over-thermal (RoT) threshold can be set at an access point based on one or more parameters, such as pathloss measurements, location of the access point, etc., such that interference from devices communicating with the access point can be mitigated. In addition, a noise floor, RoT threshold, etc., can be adjusted based on determining a transmit power difference, out-of-cell interference, and/or similar measurements.

Claims

1. A method for setting a rise-over-thermal (RoT) threshold for a femtocell access point, comprising:

receiving one or more parameters corresponding to one or more access points;

determining a RoT threshold for the femtocell access point based at least in part on the one or more parameters; and

setting the RoT threshold at the femtocell access point.

2. The method of claim 1, wherein the receiving the one or more parameters comprises obtaining a first pathloss measurement of at least one device to the femtocell access point, and obtaining a second pathloss measurement of the at least one device to a second access point.

3. The method of claim 2, wherein the receiving the one or more parameters comprises obtaining additional first pathloss measurements from at least another device to the femtocell access point, and obtaining additional second pathloss measurements from the at least another device to the second access point, and wherein the determining the RoT threshold is further based at least in part on a function of a difference between the additional first pathloss measurements and the additional second pathloss measurements.

4. The method of claim 2, wherein the receiving the one or more parameters further comprises obtaining one or more additional pathloss measurements of the at least one device to one or more additional access points, and wherein the determining the RoT is based at least in part on a function of a difference between the first pathloss measurement and a minimum of the second pathloss measurement and the one or more additional pathloss measurements.

5. The method of claim 2, wherein the at least one device is a network listening module co-located within the femtocell access point.

6. The method of claim 2, further comprising configuring the at least one device to report at least the first pathloss measurement and the second pathloss measurement as part of a training period.

7. The method of claim 1, further comprising:

determining a maximum transmit power for devices communicating with the femtocell access point; and

determining another RoT threshold based at least in part on the maximum transmit power.

8. The method of claim 7, wherein the setting the RoT threshold comprises setting the RoT threshold as a minimum of the RoT threshold and the another RoT threshold.

9. The method of claim 1, wherein the receiving the one or more parameters comprises receiving a location of the femtocell access point within a macrocell, and the determining the RoT threshold is based at least in part on a distance computed between the femtocell access point and one or more other access points within the macrocell.

10. An apparatus for setting a rise-over-thermal (RoT) threshold for a femtocell access point, comprising:

at least one processor configured to;

receive one or more parameters corresponding to one or more access points;

determine a RoT threshold for the femtocell access point based at least in part on the one or more parameters; and

set the RoT threshold at the femtocell access point; and

a memory coupled to the at least one processor.

11. The apparatus of claim 10, wherein the one or more parameters comprise a first pathloss measurement of at least one device to the femtocell access point, and a second pathloss measurement of the at least one device to a second access point.

12. The apparatus of claim 11, wherein the one or more parameters comprise an additional first pathloss measurements from at least another device to the femtocell access point, and an additional second pathloss measurements from the at least another device to the second access point, and wherein the at least one processor determines the RoT threshold further based at least in part on a function of a difference between the additional first pathloss measurements and the additional second pathloss measurements.

13. The apparatus of claim 11, wherein the at least one processor is further configured to obtain one or more additional pathloss measurements of the at least one device to one or more additional access points, and wherein the one or more parameters comprise the one or more additional pathloss measurements.

14. The apparatus of claim 11, wherein the at least one device is a network listening module co-located at the femtocell access point.

15. An apparatus for setting a rise-over-thermal (RoT) threshold for a femtocell access point, comprising:

means for receiving one or more parameters corresponding to one or more access points;

means for determining a RoT threshold for the femtocell access point based at least in part on the one or more parameters; and

means for setting the RoT threshold at the femtocell access point.

16. The apparatus of claim 15, wherein the one or more parameters comprise a first pathloss measurement of at least one device to the femtocell access point and a second pathloss measurement of the at least one device to a second access point.

17. The apparatus of claim 16, wherein the one or more parameters comprise an additional first pathloss measurements from at least another device to the femtocell access point, and an additional second pathloss measurements from the at least another device to the second access point, and wherein the means for determining determines the RoT threshold further based at least in part on a function of a difference between the additional first pathloss measurements and the additional second pathloss measurements.

18. The apparatus of claim 16, wherein the means for receiving further obtains one or more additional pathloss measurements of the at least one device to one or more additional femtocell access points, wherein the one or more parameters further comprise the one or more additional pathloss measurements.

19. The apparatus of claim 16, further comprising means for processing one or more signals from the first or the second access point, wherein the at least one device comprises the means for processing.

20. A computer program product for setting a rise-over-thermal (RoT) threshold for a femtocell access point, comprising:

a computer-readable medium, comprising;

code for causing at least one computer to receive one or more parameters corresponding to one or more access points;

code for causing the at least one computer to determine a RoT threshold for the femtocell access point based at least in part on the one or more parameters; and

code for causing the at least one computer to set the RoT threshold at the femtocell access point.

21. The computer program product of claim 20, wherein the one or more parameters comprise a first pathloss measurement of at least one device to the femtocell access point, and a second pathloss measurement of the at least one device to a second access point.

22. The computer program product of claim 21, wherein the one or more parameters comprise an additional first pathloss measurements from at least another device to the femtocell access point, and an additional second pathloss measurements from the at least another device to the second access point, and wherein the code for causing the at least one computer to determine determines the RoT threshold further based at least in part on a function of a difference between the additional first pathloss measurements and the additional second pathloss measurements.

23. The computer program product of claim 21, wherein the computer-readable medium further comprises code for causing the at least one computer to obtain one or more additional pathloss measurements of the at least one device to one or more additional access points, and wherein the one or more parameters comprise the one or more additional pathloss measurements.

24. The computer program product of claim 21, wherein the at least one device is a network listening module co-located at the femtocell access point.

25. An apparatus for setting a rise-over-thermal (RoT) threshold for a femtocell access point, comprising:

a parameter receiving component for receiving one or more parameters corresponding to one or more access points;

a RoT threshold determining component for determining a RoT threshold for the femtocell access point based at least in part on the one or more parameters; and

a RoT threshold setting component for setting the RoT threshold at the femtocell access point.

26. The apparatus of claim 25, wherein the one or more parameters comprise a first pathloss measurement of at least one device to the femtocell access point and a second pathloss measurement of the at least one device to a second access point, wherein the one or more parameters comprise the first pathloss measurement and the second pathloss measurement.

27. The apparatus of claim 26, wherein the one or more parameters comprise an additional first pathloss measurements from at least another device to the femtocell access point, and an additional second pathloss measurements from the at least another device to the second access point, and wherein the RoT threshold determining component determines the RoT threshold further based at least in part on a function of a difference between the additional first pathloss measurements and the additional second pathloss measurements.

28. The apparatus of claim 26, wherein the parameter receiving component further obtains one or more additional pathloss measurements of the at least one device to one or more additional femtocell access points, wherein the one or more parameters further comprise the one or more additional pathloss measurements.

29. The apparatus of claim 26, further comprising a network listening module (NLM) component for processing one or more signals from the first or the second access point, wherein the at least one device comprises the NLM component.

30. The apparatus of claim 26, further comprising a measurement requesting component for configuring the at least one device to report at least the first pathloss measurement and the second pathloss measurement as part of a training period.

31. The apparatus of claim 25, wherein the parameter receiving component determines a maximum transmit power for devices communicating with the femtocell access point, wherein the RoT threshold determining component determines another RoT threshold based at least in part on the maximum transmit power.

32. The apparatus of claim 31, wherein the RoT threshold determining component determines the RoT threshold as a minimum of the RoT threshold and the another RoT threshold.

33. The apparatus of claim 25, wherein the one or more parameters comprise a location of the femtocell access point within a macrocell, and the RoT threshold determining component determines the RoT threshold based at least in part on a distance computed between the femtocell access point and one or more other access points within the macrocell.

34. A method for adjusting parameters of an access point based on determining interference, comprising:

detecting a strongest transmit power of one or more access points;

determining whether the strongest transmit power exceeds a transmit power utilized at a femtocell access point; and

adjusting an estimated noise floor of the femtocell access point based at least in part on whether the strongest transmit power exceeds the transmit power.

35. The method of claim 34, further comprising estimating a level of out-of-cell interference, wherein the adjusting the estimated noise floor is further based at least in part on the level of out-of-cell interference.

36. The method of claim 35, wherein the estimating the level of out-of-cell interference comprises measuring noise during a period of time.

37. The method of claim 34, further comprising adjusting a rise-over-thermal threshold of the femtocell access point based at least in part on whether the strongest transmit power exceeds the transmit power.

38. The method of claim 34, wherein the adjusting the estimated noise floor comprises adjusting the estimated noise floor of the femtocell access point for a given device that is served by a different access point in soft handover.

39. The method of claim 38, further comprising:

requesting identifiers of devices served by the access point in soft handover; and

receiving an identifier of the given device from the different access point based at least in part on the request.

40. The method of claim 34, further comprising enforcing the estimated noise floor for communications with the at least one device.

41. An apparatus for adjusting parameters of an access point based on determining interference, comprising:

at least one processor configured to;

detect a strongest transmit power of one or more access points;

determine whether the strongest transmit power exceeds a transmit power utilized at a femtocell access point; and

adjust a noise floor of the femtocell access point based at least in part on whether the strongest transmit power exceeds the transmit power; and

a memory coupled to the at least one processor.

42. The apparatus of claim 41, wherein the at least one processor is further configured to estimate a level of out-of-cell interference, wherein the at least one processor adjusts the noise floor further based at least in part on the level of out-of-cell interference.

43. The apparatus of claim 41, wherein the at least one processor is further configured to adjust a rise-over-thermal threshold of the femtocell access point based at least in part on whether the strongest transmit power exceeds the transmit power.

44. The apparatus of claim 41, wherein the at least one processor adjusts the noise floor of the femtocell access point for a given device that is served by a different access point in soft handover.

45. The apparatus of claim 44, wherein the at least one processor is further configured to request identifiers of device served by the access point in soft handover and receive an identifier of the given device from the different access point based at least in part on the request.

46. An apparatus for adjusting parameters of an access point based on determining interference, comprising:

means for detecting a strongest transmit power of one or more access points; and

means for adjusting a noise floor of a femtocell access point based at least in part on determining whether the strongest transmit power exceeds a transmit power of the femtocell access point.

47. The apparatus of claim 46, wherein the means for detecting further estimates a level of out-of-cell interference, and the means for adjusting adjusts the noise floor further based at least in part on the level of out-of-cell interference.

48. The apparatus of claim 46, further comprising means for adjusting a rise-over-thermal threshold of the femtocell access point based at least in part on whether the strongest transmit power exceeds the transmit power.

49. The apparatus of claim 46, wherein the means for adjusting adjusts the noise floor of the femtocell access point for a given device that is served by a different access point in soft handover.

50. The apparatus of claim 49, further comprising means for requesting identifiers of devices served by the access point in soft handover and receiving an identifier of the given device from the different access point based at least in part on the request.

51. A computer program product for adjusting parameters of an access point based on determining interference, comprising:

a computer-readable medium, comprising;

code for causing at least one computer to detect a strongest transmit power of one or more access points;

code for causing the at least one computer to determine whether the strongest transmit power exceeds a transmit power utilized at a femtocell access point; and

code for causing the at least one computer to adjust a noise floor of the femtocell access point based at least in part on whether the strongest transmit power exceeds the transmit power.

52. The computer program product of claim 51, wherein the computer-readable medium further comprises code for causing the at least one computer to estimate a level of out-of-cell interference, wherein the code for causing the at least one computer to adjust adjusts the noise floor further based at least in part on the level of out-of-cell interference.

53. The computer program product of claim 51, wherein the computer-readable medium further comprises code for causing the at least one computer to adjust a rise-over-thermal threshold of the femtocell access point based at least in part on whether the strongest transmit power exceeds the transmit power.

54. The computer program product of claim 51, wherein the code for causing the at least one computer to adjust adjusts the noise floor of the femtocell access point for a given device that is served by a different access point in soft handover.

55. The computer program product of claim 54, wherein the computer-readable medium further comprises code for causing the at least one computer to request identifiers of device served by the access point in soft handover and receive an identifier of the given device from the different access point based at least in part on the request.

56. An apparatus for adjusting parameters of an access point based on determining interference, comprising:

an interference determining component for detecting a strongest transmit power of one or more access points; and

a noise floor adjusting component for adjusting a noise floor of a femtocell access point based at least in part on determining whether the strongest transmit power exceeds a transmit power of the femtocell access point.

57. The apparatus of claim 56, wherein the interference determining component further estimates a level of out-of-cell interference, and the noise floor adjusting component adjusts the noise floor further based at least in part on the level of out-of-cell interference.

58. The apparatus of claim 57, wherein the interference determining component estimates the level of out-of-cell interference at least in part by measuring noise during a period of time.

59. The apparatus of claim 56, further comprising a rise-over-thermal (RoT) threshold adjusting component for adjusting a RoT threshold of the femtocell access point based at least in part on whether the strongest transmit power exceeds the transmit power.

60. The apparatus of claim 56, wherein the noise floor adjusting component adjusts the noise floor of the femtocell access point for a given device that is served by a different access point in soft handover.

61. The apparatus of claim 60, a soft handover (SHO) device requesting component for requesting identifiers of devices served by the access point in SHO and receiving an identifier of the given device from the different access point based at least in part on the request.

62. The apparatus of claim 56, wherein the noise floor adjusting component reports the noise floor to at least one device.