ADAPTATION OF TRANSMIT POWER FOR NEIGHBORING NODES

• US 20090042593A1
• Filed: 08/06/2008
• Published: 02/12/2009
• Est. Priority Date: 08/10/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: El-Khamy, Mostafa S., Nanda, Sanjiv, Yavuz, Mehmet
• Granted Patent: US 8,909,279 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 16/16 for PBS [Private Base Station] arrangements
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 52/143 Downlink power control
• 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 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

Transmit power (e.g., maximum transmit power) may be defined based on the maximum received signal strength allowed by a receiver and a minimum coupling loss from a transmitting node to a receiver. Transmit power may be defined for an access node (e.g., a femto node) such that a corresponding outage created in a cell (e.g., a macro cell) is limited while still providing an acceptable level of coverage for access terminals associated with the access node. An access node may autonomously adjust its transmit power based on channel measurement and a defined coverage hole to mitigate interference. Transmit power may be defined based on channel quality. Transmit power may be defined based on a signal-to-noise ratio at an access terminal. The transmit power of neighboring access nodes also may be controlled by inter-access node signaling.

Claims

1. A method of wireless communication, comprising:

receiving at least one indication regarding pilot strength of at least one node;

identifying, based on the at least one indication, a node of the at least one node that should reduce transmit power; and

transmitting a message requesting a reduction in transmit power by the identified node.

2. The method of claim 1, wherein the at least one indication is received from an access terminal that measured the pilot strength of the at least one node.

3. The method of claim 2, wherein the identification of the node comprises determining whether coverage at the access terminal is acceptable.

4. The method of claim 1, wherein the coverage relates to a desired coverage radius and/or a desired quality of service.

5. The method of claim 1, wherein the at least one indication comprises a received signal code power measurement for each of the at least one node.

6. The method of claim 1, wherein the at least one indication comprises a total received signal strength indication.

7. The method of claim 1, wherein the identification of the node comprises determining which node of the at least one node has a higher indication of pilot strength.

8. The method of claim 1, wherein the message comprises an indication of a degree to which the transmit power should be reduced.

9. The method of claim 1, wherein the message is transmitted to the identified node.

10. The method of claim 1, wherein the message is transmitted to a centralized power controller.

11. The method of claim 1, wherein:

the indication is received at an access node that is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node; and

the identified node is a neighbor of the access node and is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node.

12. The method of claim 1, wherein:

the indication is received at an access node;

the access node is a femto node or a pico node;

the identified node is a neighbor of the access node; and

the identified node is a femto node or a pico node.

13. The method of claim 1, wherein:

the indication is received at a centralized power controller; and

the identified node is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node.

14. The method of claim 1, wherein:

the indication is received at a centralized power controller; and

the identified node is a femto node or a pico node.

15. The method of claim 1, further comprising:

receiving a request to reduce transmit power;

determining whether an associated access terminal will have adequate coverage if the transmit power is reduced; and

transmitting a response to the request based on the determination.

16. The method of claim 15, wherein the determination is based on a desired coverage radius and/or a desired quality of service.

17. An apparatus for wireless communication, comprising:

a receiver configured to receive at least one indication regarding pilot strength of at least one node;

a transmit power controller configured to identify, based on the at least one indication, a node of the at least one node that should reduce transmit power; and

a transmitter configured to transmit a message requesting a reduction in transmit power by the identified node.

18. The apparatus of claim 17, wherein the at least one indication is received from an access terminal that measured the pilot strength of the at least one node.

19. The apparatus of claim 18, wherein the identification of the node comprises determining whether coverage at the access terminal is acceptable.

20. The apparatus of claim 17, wherein the coverage relates to a desired coverage radius and/or a desired quality of service.

21. The apparatus of claim 17, wherein the at least one indication comprises a received signal code power measurement for each of the at least one node.

22. The apparatus of claim 17, wherein the at least one indication comprises a total received signal strength indication.

23. The apparatus of claim 17, wherein the identification of the node comprises determining which node of the at least one node has a higher indication of pilot strength.

24. The apparatus of claim 17, wherein the message comprises an indication of a degree to which the transmit power should be reduced.

25. The apparatus of claim 17, wherein the message is transmitted to the identified node.

26. The apparatus of claim 17, wherein the message is transmitted to a centralized power controller.

27. The apparatus of claim 17, wherein:

the indication is received at an access node that is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node; and

the identified node is a neighbor of the access node and is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node.

28. The apparatus of claim 17, wherein:

the indication is received at an access node;

the access node is a femto node or a pico node;

the identified node is a neighbor of the access node; and

the identified node is a femto node or a pico node.

29. The apparatus of claim 17, wherein:

the indication is received at a centralized power controller; and

the identified node is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node.

30. The apparatus of claim 17, wherein:

the indication is received at a centralized power controller; and

the identified node is a femto node or a pico node.

31. The apparatus of claim 17, wherein:

the receiver is further configured to receive a request to reduce transmit power;

the transmit power controller is further configured to determine whether an associated access terminal will have adequate coverage if the transmit power is reduced; and

the transmitter is further configured to transmit a response to the request based on the determination.

32. The apparatus of claim 31, wherein the determination is based on a desired coverage radius and/or a desired quality of service.

33. An apparatus for wireless communication, comprising:

means for receiving at least one indication regarding pilot strength of at least one node;

means for identifying, based on the at least one indication, a node of the at least one node that should reduce transmit power; and

means for transmitting a message requesting a reduction in transmit power by the identified node.

34. The apparatus of claim 33, wherein the at least one indication is received from an access terminal that measured the pilot strength of the at least one node.

35. The apparatus of claim 34, wherein the identification of the node comprises determining whether coverage at the access terminal is acceptable.

36. The apparatus of claim 33, wherein the coverage relates to a desired coverage radius and/or a desired quality of service.

37. The apparatus of claim 33, wherein the at least one indication comprises a received signal code power measurement for each of the at least one node.

38. The apparatus of claim 33, wherein the at least one indication comprises a total received signal strength indication.

39. The apparatus of claim 33, wherein the identification of the node comprises determining which node of the at least one node has a higher indication of pilot strength.

40. The apparatus of claim 33, wherein the message comprises an indication of a degree to which the transmit power should be reduced.

41. The apparatus of claim 33, wherein the message is transmitted to the identified node.

42. The apparatus of claim 33, wherein the message is transmitted to a centralized power controller.

43. The apparatus of claim 33, wherein:

the indication is received at an access node that is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node; and

the identified node is a neighbor of the access node and is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node.

44. The apparatus of claim 33, wherein:

the indication is received at an access node;

the access node is a femto node or a pico node;

the identified node is a neighbor of the access node; and

the identified node is a femto node or a pico node.

45. The apparatus of claim 33, wherein:

the indication is received at a centralized power controller; and

the identified node is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node.

46. The apparatus of claim 33, wherein:

the indication is received at a centralized power controller; and

the identified node is a femto node or a pico node.

47. The apparatus of claim 33, wherein:

the means for receiving is configured to receive a request to reduce transmit power;

the means for identifying is configured to determine whether an associated access terminal will have adequate coverage if the transmit power is reduced; and

the means for transmitting is configured to transmit a response to the request based on the determination.

48. The apparatus of claim 47, wherein the determination is based on a desired coverage radius and/or a desired quality of service.

49. A computer-program product, comprising:

computer-readable medium comprising codes for causing a computer to;

receive at least one indication regarding pilot strength of at least one node;

identify, based on the at least one indication, a node of the at least one node that should reduce transmit power; and

transmit a message requesting a reduction in transmit power by the identified node.

50. The computer-program product of claim 49, wherein the at least one indication is received from an access terminal that measured the pilot strength of the at least one node.

51. The computer-program product of claim 50, wherein the identification of the node comprises determining whether coverage at the access terminal is acceptable.

52. The computer-program product of claim 49, wherein the coverage relates to a desired coverage radius and/or a desired quality of service.

53. The computer-program product of claim 49, wherein the at least one indication comprises a received signal code power measurement for each of the at least one node.

54. The computer-program product of claim 49, wherein the at least one indication comprises a total received signal strength indication.

55. The computer-program product of claim 49, wherein the identification of the node comprises determining which node of the at least one node has a higher indication of pilot strength.

56. The computer-program product of claim 49, wherein the message comprises an indication of a degree to which the transmit power should be reduced.

57. The computer-program product of claim 49, wherein the message is transmitted to the identified node.

58. The computer-program product of claim 49, wherein the message is transmitted to a centralized power controller.

59. The computer-program product of claim 49, wherein:

the indication is received at an access node that is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node; and

the identified node is a neighbor of the access node and is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node.

60. The computer-program product of claim 49, wherein:

the indication is received at an access node;

the access node is a femto node or a pico node;

the identified node is a neighbor of the access node; and

the identified node is a femto node or a pico node.

61. The computer-program product of claim 49, wherein:

the indication is received at a centralized power controller; and

the identified node is restricted for least one of the group consisting of;

signaling, data access, registration, paging, and service to at least one node.

62. The computer-program product of claim 49, wherein:

the indication is received at a centralized power controller; and

the identified node is a femto node or a pico node.

63. The computer-program product of claim 49, wherein:

the computer-readable medium further comprises codes for causing the computer to receive a request to reduce transmit power;

the computer-readable medium further comprises codes for causing the computer to determine whether an associated access terminal will have adequate coverage if the transmit power is reduced; and

the computer-readable medium further comprises codes for causing the computer to transmit a response to the request based on the determination.

64. The computer-program product of claim 63, wherein the determination is based on a desired coverage radius and/or a desired quality of service.