Methods and apparatus for tracking wireless terminal power information

• US 7,853,281 B2
• Filed: 07/14/2006
• Issued: 12/14/2010
• Est. Priority Date: 04/14/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Das, Arnab, Rangan, Sundeep, Celebi, Samel
• Primary Examiner(s): Rego; Dominic E
• Application Number:
  US11/487,262
• Publication Number:
  US 20070243894A1
• Time in Patent Office: 1,614 Days
• Field of Search: 455/522, 455/67.11, 455 68- 70, 455/115.3, 455/126, 455/127.1, 455/127.2, 455/135, 455/226.3, 455/277.2, 455/296, 370/318, 370/335, 370/342
• US Class Current: 455/522
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04W 52/56 Detection of errors of TPC bits
• CPC Class Codes: H04W 52/58 Format of the TPC bits

Abstract

Power control reports are communicated less frequently than the power control commands. The base station tracks the commands sent to the wireless terminal and estimates the wireless terminal'"'"'s control channel transmit power. Received power control channel reports are utilized to compare the base station'"'"'s estimated wireless terminal control channel transmit power to the actual wireless terminal control channel transmit power. An estimate of the error rate of transmitted power control signals is generated based using the tracked power command information and received power report information. Adjustments are performed in the power control command signaling to compensate for estimated error rates.

Claims

1. A method of operating a base station, the method comprising:

receiving a report communicating transmission power information from said wireless terminal indicative of an amount of power dedicated for use in transmitting the predetermined set of signals to said base station;

transmitting power control signals to said a wireless terminal over a period of time;

estimating, based on the transmitted power control signals, an amount of power dedicated by said wireless terminal for transmitting a predetermined set of signals,

wherein estimating the amount of power dedicated by said wireless terminal for transmitting on said predetermined set of signals is also based on tie report communicating transmission power information; and

determining based on the estimated amount of power dedicated by said wireless terminal for transmitting said predetermined set of signals, an amount of remaining power available at said wireless terminal for other uplink transmissions.

2. The method of claim 1, wherein said report communicating transmission power information indicates a ratio of a maximum transmit power of the wireless terminal to a transmit power of a reference signal.

3. The method of claim 2, wherein said estimating is performed using said received power information, said received power information corresponding to a point in time, and information indicating changes in said dedicated transmission power specified by said transmitted control signals.

4. The method of claim 3, wherein said power information indicates an amount of power dedicated for transmitting said predetermined set of signals during a single transmission time period.

5. The method of claim 1, wherein reports communicating transmission power information are received at a first rate and wherein said power control signals are sent at a second rate which is faster than said first rate.

6. The method of claim 1, further comprising:

determining, based on the amount of remaining power available at said wireless terminal for other uplink transmissions at least one of a maximum transmission rate and a maximum transmission power to be used by said wireless terminal for at least some uplink traffic.

7. The method of claim 6, further comprising:

generating an estimate of the power adjustment signal error rate; and

modifying the estimated amount of power as a function of the estimated error rate.

8. The method of claim 7, wherein said modifying is a function of the power control signals transmitted during a time period preceding said modifying of the estimated amount of power.

9. The method of claim 1, further comprising:

determining the power control signal to be transmitted at a particular point in time as a function of a quality measurement of a received signal and a desired received signal quality level.

10. The method of claim 1, wherein said predetermined set of signals correspond to a control channel, said report communicating transmission power information indicating the transmission power used on the said control channel.

11. The method of claim 1, wherein determining said amount of remaining power available at said wireless terminal includes determining the amount of power available at said wireless terminal for uplink transmissions remaining after said estimated amount of power is removed from a maximum available uplink power amount.

12. The method of claim 1, wherein estimating the amount of power dedicated by said wireless terminal during said period of time for transmitting said predetermined set of signals includes using at least one of an uplink communication delay and a downlink communication delay.

13. The method of claim 12, wherein said uplink communication delay includes an uplink transmission delay and uplink signal processing delay and wherein said downlink communication delay includes a downlink transmission delay and downlink signal processing delay.

14. A base station comprising:

a receiver module for receiving a report communicating transmission power information from said wireless terminal indicative of an amount of power dedicated for use in transmitting the predetermined set of signals to said base station;

a transmitter for transmitting power control signals to a wireless terminal over a period of time; and

an estimation module for estimating, based on the transmitted power control signals, an amount of power dedicated by said wireless terminal for transmitting a predetermined set of signals,

wherein estimating the amount of power dedicated by said wireless terminal for transmitting on said predetermined set of signals is also based on the report communicating transmission power information; and

a determination module for determining, based on the estimated amount of power dedicated by said wireless terminal for transmitting said predetermined set of signals, an amount of remaining power available at said wireless terminal for other uplink transmissions.

15. The base station of claim 14, wherein said report communicating transmission power information indicates a ratio of a maximum transmit power of the wireless terminal to a transmit power of a reference signal.

16. The base station of claim 15, wherein said estimating is performed by said estimation module using said received power information, said received power information corresponding to a point in time, and information indicating changes in said dedicated transmission power specified by said transmitted control signals.

17. The base station of claim 16, wherein said power information indicates an amount of power dedicated for transmitting said predetermined set of signals during a single transmission time period.

18. The base station of claim 14 wherein reports communicating transmission power information are received at a first rate and wherein said power control signals are sent at a second rate which is faster than said first rate.

19. The base station of claim 14, wherein said determination module is further configured to determine, based on the amount of remaining power available at said wireless terminal for other uplink transmissions, at least one of maximum transmission rate and a maximum transmission power to be used by said wireless terminal for at least some uplink traffic.

20. The base station of claim 19, wherein said predetermined set of signals correspond to a control channel, said report communicating transmission power information indicating the transmission power used on the said control channel.

21. The base station of claim 19, further comprising:

an error estimation module for generating an estimate of the power adjustment signal error rate; and

an adjustment module for modifying the estimated amount of power as a function of the estimated error rate.

22. The base station of claim 21, wherein said adjustment module modifies the estimated amount of power as a function of the power control signals transmitted during a time period preceding said modifying of the estimated amount of power.

23. The base station of claim 14, further comprising:

a power control signaling module for determining the power control signal to be transmitted at a particular point in time as a function of a quality measurement of a received signal and a desired received signal quality level.

24. The base station of claim 14 wherein the determination module determines the amount of remaining power available at said wireless terminal by removing said estimated amount of power from a maximum available uplink power amount.

25. The base station of claim 14, further comprising:

a communication delay determination module for determining at least one of an uplink communications delay and a downlink communications delay.

26. The base station of claim 25, wherein the estimation module estimates the amount of power dedicated by said wireless terminal during said period of time for transmitting said predetermined set of signals using at least one of an uplink communication delay and a downlink communication delay.

27. The base station of claim 26, wherein said uplink communication delay includes an uplink transmission delay and uplink signal processing delay and wherein said downlink communication delay includes a downlink transmission delay and downlink signal processing delay.

28. A base station comprising:

means for receiving a report communicating transmission power information from said wireless terminal indicative of an amount of power dedicated for use in transmitting a predetermined set of signals to said base station;

means for transmitting power control signals to a wireless terminal over a period of time; and

means for estimating, based on the transmitted power control signals, an amount of power dedicated by said wireless terminal for transmitting a predetermined set of signals,

wherein said means for estimating the amount of power dedicated by said wireless terminal for transmitting said predetermined set of signals, estimates said amount of power also based on the report communicating transmission power information; and

means for determining based on the estimated amount of power dedicated by said wireless terminal for transmitting said predetermined set of signals, an amount of remaining power available at said wireless terminal for other uplink transmissions.

29. The base station of claim 28, wherein said report communicating transmission power information indicates a ratio of a maximum transmit power of the wireless terminal to a transmit power of a reference signal.

30. The base station of claim 29, wherein said estimating is performed using said received power information, said received power information corresponding to a point in time, and information indicating changes in said dedicated transmission power specified by said transmitted control signals.

31. The base station of claim 30, wherein said power information indicates an amount of power dedicated for transmitting said predetermined set of signals during a single transmission time period.

32. The base station of claim 28, wherein communicating transmission power information are received at a first rate and wherein said power control signals are sent at a second rate which is faster than said first rate.

33. The base station of claim 28,

wherein said means for determining include means for determining at least one of a maximum transmission rate and a maximum transmission power to be used by said wireless terminal for at least some uplink traffic, based on the amount of remaining power available at said wireless terminal for other uplink transmissions.

34. The base station of claim 33, wherein said predetermined set of signals correspond to a control channel, said report communicating transmission power information indicating the transmission power used on the said control channel.

35. The base station of claim 33, further comprising:

means for generating an estimate of the power adjustment signal error rate; and

means for modifying the estimated amount of power as a function of the estimated error rate.

36. The base station of claim 35, wherein said means for modifying the estimated amount of power modifies the estimated amount of power as a function of the power control signals transmitted during a time period preceding said modifying of the estimated amount of power.

37. The base station of claim 28, further comprising:

means for determining the power control signal to be transmitted at a particular point in time as a function of a quality measurement of a received signal and a desired received signal quality level.

38. The base station of claim 28, wherein the means for determining an amount of remaining power available at said wireless terminal determines the amount of power available at said wireless terminal for uplink transmissions remaining after said estimated amount of power is removed from a maximum available uplink power amount.

39. The base station of claim 28, further comprising:

means for determining at least one of an uplink communications delay and a downlink communications delay.

40. The base station of claim 39, wherein the means for estimating estimates the amount of power dedicated by said wireless terminal during said period of time for transmitting said predetermined set of signals using at least one of an uplink communication delay and a downlink communication delay.

41. The base station of claim 40, wherein said uplink communication delay includes an uplink transmission delay and uplink signal processing delay and wherein said downlink communication delay includes a downlink transmission delay and downlink signal processing delay.

42. A non-transitory machine readable medium including machine executable instructions stored therein for implementing a method of operating a base station, the method comprising:

receiving a report communicating transmission power information from said wireless terminal indicative of an amount of power dedicated for use in transmitting the predetermined set of signals to said base station;

transmitting power control signals to a wireless terminal over a period of time;

estimating, based on the transmitted power control signals, an amount of power dedicated by said wireless terminal for transmitting a predetermined set of signals,

wherein estimating the amount of power dedicated by said wireless terminal for transmitting on said predetermined set of signals is also based on the report communicating transmission power information; and

determining based on the estimated amount of power dedicated by said wireless terminal for transmitting said predetermined set of signals, an amount of remaining power available at said wireless terminal for other uplink transmissions.

43. The non-transitory machine readable medium of claim 42, wherein said report communicating transmission power information indicates a ratio of a maximum transmit power of the wireless terminal to a transmit power of a reference signal.

44. The non-transitory machine readable medium of claim 43, wherein said estimating is performed using said received power information, said received power information corresponding to a point in time, and information indicating changes in said dedicated transmission power specified by said transmitted control signals.

45. The non-transitory machine readable medium of claim 44, wherein said power information indicates an amount of power dedicated for transmitting said predetermined set of signals during a single transmission time period.

46. The non-transitory machine readable medium of claim 42, wherein reports communicating transmission power information are received at a first rate and wherein said power control signals are sent at a second rate which is faster than said first rate.

47. The non-transitory machine readable medium of claim 42, further embodying machine executable instructions for:

determining, based on the amount of remaining power available at said wireless terminal for other uplink transmissions, at least one of a maximum transmission rate and a maximum transmission power to be used by said wireless terminal for at least some uplink traffic.

48. The non-transitory machine readable medium of claim 42, further embodying machine executable instructions for:

determining the power control signal to be transmitted at a particular point in time as a function of a quality measurement of a received signal and a desired received signal quality level.

49. The non-transitory machine readable medium of claim 42 wherein said predetermined set of signals correspond to a control channel, said report communicating transmission power information indicating the transmission power used on the said control channel.

50. The non-transitory machine readable medium of claim 42, where said machine executable instructions for determining said amount of remaining power include machine executable instructions for:

determining said amount of remaining power by removing said estimated amount of power dedicated by said wireless terminal from a maximum available uplink power amount.

51. The non-transitory machine readable medium of claim 42, further embodying machine executable instructions for:

generating an estimate of the power adjustment signal error rate; and

modifying the estimated amount of power as a function of the estimated power adjustment signal error rate.

52. The non-transitory machine readable medium of claim 51, wherein said modifying is a function of the power control signals transmitted during a time period preceding said modifying of the estimated amount of power.

53. An apparatus operable in a communication system, the apparatus comprising:

a processor configured to;

receive a report communicating transmission power information from said wireless terminal indicative of an amount of power dedicated for use in transmitting the predetermined set of signals to said base station;

transmit power control signals to a wireless terminal over a period of time;

estimate, based on the transmitted power control signals, an amount of power dedicated by said wireless terminal for transmitting a predetermined set of signals,

wherein said processor is configured to estimate the amount of power dedicated by said wireless terminal for transmitting on said predetermined set of signals also based on the report communicating transmission power information; and

determine based on the estimated amount of power dedicated by said wireless terminal for transmitting said predetermined set of signals, an amount of remaining power available at said wireless terminal for other uplink transmissions.

54. The apparatus of claim 53, wherein the processor is configured to:

remove said estimated amount of power form a maximum available uplink power amount as part of determining said amount of remaining power available at said wireless terminal.