SYSTEMS AND TECHNIQUES FOR CHANNEL GAIN COMPUTATIONS

• US 20030114180A1
• Filed: 03/20/2002
• Published: 06/19/2003
• Est. Priority Date: 12/14/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Black, Peter J., Sindhushayana, Nagabhushana, Challa, Raghu, Attar, Rashid
• Granted Patent: US 6,594,501 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/26 using transmission rate or quality of service QoS [Quality of Service]
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets

Abstract

Systems and techniques for controlling transmission power involve receiving a first to second channel power ratio, receiving a first to second channel power ratio, adjusting the power ratio if a combined power of a plurality of channels exceeds a threshold, the channels including the first and second channels, and computing gain of the first channel as a function of the power ratio. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Claims

1. A method of controlling transmission power, comprising:

receiving a first to second channel power ratio;

adjusting the power ratio if a combined power of a plurality of channels exceeds a threshold, the channels including the first and second channels; and

computing gain of the first channel as a function of the power ratio.

2. The method of claim 1 further comprising applying the computed gain to the first channel, combining the channels, and applying a second gain to the combined channels.

3. The method of claim 2 wherein the application of the second gain comprises setting power of the second channel as a function of a criterion.

4. The method of claim 3 wherein the criterion comprises minimum power to achieve a quality of service at a remote site.

5. The method of claim 2 wherein the application of the second gain comprises computing the second gain as a function of received power of a transmission from a remote site.

6. The method of claim 2 wherein the application of the second gain comprises recovering a power command from a transmission received from a remote site and computing the second gain as a function of the recovered power command.

7. The method of claim 2 further comprising spreading each channel with a different code.

8. The method of claim 7 wherein the different codes each comprises a Walsh function.

9. The method of claim 1 wherein the power ratio adjustment comprises computing the combined power of the channels as a function of the power ratio and power for the second channel, comparing the combined power computation to the threshold, and reducing the power ratio if the combined power computation exceeds the threshold.

10. The method of claim 9 further comprising computing the power for the second channel as a function of a criterion.

11. The method of claim 10 wherein the criterion comprises minimum power to achieve a quality of service at a remote site.

12. The method of claim 10 wherein the power computation for the second channel comprises computing the power for the second channel as a function of received power of a transmission from a remote site.

13. The method of claim 10 wherein the power computation for the second channel comprises recovering a power command from a transmission received from a remote site and computing the power for the second channel as a function of the recovered power command.

14. The method of claim 9 wherein the power ratio reduction comprises reducing the power ratio in incremental steps.

15. The method of claim 9 wherein the power ratio reduction comprises computing the power ratio reduction as a function of the threshold.

16. The method of claim 1 wherein the channels further comprise a third channel, the method further comprising receiving a third to second channel power ratio, adjusting the third to second channel power ratio if the combined power of the channels exceeds the threshold with the first to second power ratio adjusted to zero, and computing gain of the third channel as a function of the third to second channel power ratio.

17. The method of claim 16 wherein the third to second channel power ratio adjustment comprises computing the combined power of the channels as a function of the third to second power ratio with the first to second power ratio adjusted to zero, comparing the combined power computation to the threshold, and reducing the third to second channel power ratio if the combined power computation exceeds the threshold.

18. The method of claim 17 wherein the third to second channel power ratio reduction comprises reducing the third to second channel power ratio in incremental steps.

19. The method of claim 17 wherein the third to second channel power ratio reduction comprises computing the third to second channel power ratio reduction as a function of the threshold.

20. The method of claim 1 further comprising receiving, in addition to the first to second channel power ratio, a power ratio for each remaining channel with respect to the second channel, and wherein the gain computation comprises dividing the square root of the first to second power ratio by the square root of the sum of the first to second channel power ratio and the power ratios for each of the remaining channels.

21. The method of claim 20 further comprising applying the computed gain to the first channel, combining the channels, and applying a second gain to the combined channels.

22. The method of claim 21 wherein the application of the second gain comprises computing the second gain as a function of received power of a transmission from a remote site.

23. The method of claim 21 wherein the application of the second gain comprises recovering a power command from a transmission received from a remote site and computing the second gain as a function of the recovered power command.

24. Computer readable media embodying a method of controlling transmission power, the method comprising:

receiving a first to second power ratio;

adjusting the power ratio if a combined power of a plurality of channels exceeds a threshold, the channels including the first and second channels; and

computing gain of the first channel as a function of the power ratio.

25. The computer-readable media of claim 24 wherein the power ratio adjustment comprises computing the combined power of the channels as a function of the power ratio and power for the second channel, comparing the combined power computation to the threshold, and reducing the power ratio if the combined power computation exceeds the threshold.

26. The computer-readable media of claim 25 wherein the method further comprises computing the power for the second channel as a function of a criterion.

27. The computer-readable media of claim 26 wherein the criterion comprises minimum power to achieve a quality of service at a remote site.

28. The computer-readable media of claim 25 wherein the power computation for the second channel comprises computing the power for the second channel as a function of received power of a transmission from a remote site.

29. The computer-readable media of claim 25 wherein the power computation for the second channel comprises recovering a power command from a transmission received from a remote site and computing the power of the second channel as a function of the recovered power command.

30. The computer-readable media of claim 25 wherein the power ratio reduction comprises reducing the power ratio in incremental steps.

31. The computer-readable media of claim 25 wherein the power ratio reduction comprises computing the power ratio reduction as a function of the threshold.

32. The computer-readable media of claim 24 wherein the channels further comprise a third channel, the method further comprising receiving a third to second channel power ratio, adjusting the third to second channel power ratio if the combined power of the channels exceeds the threshold with the first to second power ratio adjusted to zero, and computing gain of the third channel as a function of the third to second channel power ratio.

33. The computer-readable media of claim 32 wherein the third to second channel power ratio adjustment comprises computing the combined power of the channels as a function of the third to second channel power ratio with the first to second power ratio adjusted to zero, comparing the combined power computation to the threshold, and reducing the third to second channel power ratio if the combined power computation exceeds the threshold.

34. The computer-readable media of claim 33 wherein the third to second channel power ratio reduction comprises reducing the third to second channel power ratio in incremental steps.

35. The computer-readable media of claim 33 wherein the third to second channel power ratio reduction comprises computing the third to second power ratio reduction as a function of the threshold.

36. The computer-readable media of claim 24 wherein the method further comprises receiving, in addition to the first to second channel power ratio, a power ratio for each remaining channel with respect to the second channel, and wherein the gain computation comprises dividing the square root of the first to second channel power ratio by the square root of the sum of the first to second channel power ratio and the power ratios for each of the remaining channels.

71. The apparatus of claim 24 wherein the channels further comprise a third channel, the apparatus further comprising means for receiving a third to second channel power ratio, means for adjusting the third to second channel power ratio if the combined power of the channels exceeds the threshold with the first to second power ratio adjusted to zero, and means for computing gain of the third channel as a function of the third to second channel power ratio.

72. The apparatus of claim 71 wherein the means for adjusting the third to second channel power ration comprises means for computing the combined power of the channels as a function of the third to second channel power ratio with the first to second power ratio adjusted to zero, means for comparing the combined power computation to the threshold, and means for reducing the third to second channel power ratio if the combined power computation exceeds the threshold.

73. The apparatus of claim 72 wherein the means for reducing the third to second channel power ratio reduces the third to second channel power ratio in incremental steps.

74. The apparatus of claim 72 wherein the means for reducing the third to second channel power ratio computes the third to second power ratio reduction as a function of the threshold.

37. An apparatus, comprising:

a transmitter gain control configured to receive a first to second channel power ratio, adjust the power ratio if a combined power of a plurality of channels exceeds a threshold, the channels including the first and second channels, compute gain of the first channel as a function of the power ratio; and

a transmitter configured to apply the computed gain to the first channel, combine the channels, and apply a second gain to the combined channels.

38. The apparatus of claim 37 wherein the transmitter gain control comprises an open loop control configured to estimate received power of a transmission from a remote site, the second gain being computed by the transmitter gain control as a function of the estimated received power.

39. The apparatus of claim 37 further comprising a receiver configured to receive a transmission from a remote site, the transmission having an power command, the transmitter gain control further configured to recover the power command from the transmission received and compute the second gain as a function of the recovered power command.

40. The apparatus of claim 37 wherein the apparatus further comprising a receiver configured to receive a transmission from a remote site, the transmission having an power command, the transmitter gain control comprising a closed loop control configured to recover the power command from the transmission received and an open loop control configured to estimate received power of the transmission, the second gain being computed by the transmitter gain control as a function of the recovered power command and the estimated received power.

41. The apparatus of claim 40 wherein the transmitter gain control further comprising a summer configured to sum the recovered power command and the estimated received power, the second gain being a function of the summed power command and the estimated received power.

42. The apparatus of claim 37 wherein the transmitter comprises a modulator configured to spread each of the first and second channels with a different code before the first and second channels are combined.

43. The apparatus of claim 42 wherein the different codes each comprises a Walsh function.

44. The apparatus of claim 42 wherein the transmitter comprises a front end having a variable gain amplifier, the combined first and second channels being provided to the variable gain amplifier and the second gain being used to control the gain of the variable gain amplifier.

45. The apparatus of claim 37 wherein the transmitter gain control is configured to adjust the power ratio by computing the combined power of the channels as a function of power of the second channel and the power ratio, comparing the combined power computation to the threshold, and reducing the power ratio if the combined power computation exceeds the threshold.

46. The apparatus of claim 45 wherein the transmitter gain control comprises an open loop control configured to estimate received power of a transmission from a remote site, the power of the second channel being computed by the transmitter gain control as a function of the estimated received power.

47. The apparatus of claim 45 further comprising a receiver configured to receive a transmission from a remote site, the transmission having an power command, the transmitter gain control further configured to recover the power command from the transmission received and compute the power of the second channel as a function of the recovered power command.

48. The apparatus of claim 45 wherein the apparatus further comprising a receiver configured to receive a transmission from a remote site, the transmission having an power command, the transmitter gain control comprising a closed loop control configured to recover the power command from the transmission received and an open loop control configured to estimate received power of the transmission, the power of the second channel being computed by the transmitter gain control as a function of the recovered power command and the estimated received power.

49. The apparatus of claim 48 wherein the transmitter gain control further comprising a summer configured to sum the recovered power command and the estimated received power, the power of the second channel being a function of the summed power command and the estimated received power.

50. The apparatus of claim 45 wherein the transmitter gain control is configured to reduce the power ratio in incremental steps.

51. The apparatus of claim 45 wherein the transmitter gain control is configured to compute the power ratio reduction as a function of the threshold.

52. The apparatus of claim 37 wherein the channels further comprise a third channel, the transmitter gain control further being configured to receive a third to second channel power ratio, adjust the third to second channel power ratio if the combined power of the channels exceeds the threshold with the first to second power ratio adjusted to zero, and compute gain of the third channel as a function of the third to second channel power ratio.

53. The apparatus of claim 52 wherein the transmitter gain control is configured to adjust the third to second channel power ratio by computing the combined power of the channels as a function of the third to second channel power ratio with the first to second channel power ratio adjusted to zero, comparing the combined power computation to the threshold, and reducing the third to second channel ratio if the combined power computation exceeds the threshold.

54. The apparatus of claim 53 wherein the transmitter gain control is configured to reduce the third to second channel power ratio in incremental steps.

55. The apparatus of claim 53 wherein the transmitter gain control is configured to compute the third to second channel power ratio as a function of the threshold.

56. The apparatus of claim 52 wherein the transmitter comprises a modulator configured to spread each of the first, second and third channels with a different code before the channels are combined.

57. The apparatus of claim 56 wherein the different codes each comprises a Walsh function.

58. The apparatus of claim 37 wherein the transmitter gain control is further configured to receive a power ratio for each of the channels with respect to the second channel, and wherein the gain computation comprises dividing the square root of the first to second channel power ratio by the square root of the sum of the power ratios for each of the channels.

59. The apparatus of claim 58 wherein the transmitter gain control comprises an open loop control configured to estimate received power of a transmission from a remote site, the second gain being computed by the transmitter gain control as a function of the estimated received power.

60. The apparatus of claim 58 further comprising a receiver configured to receive a transmission from a remote site, the transmission having an power command, the transmitter gain control further configured to recover the power command from the transmission received and compute the second gain as a function of the recovered power command.

61. The apparatus of claim 58 wherein t the apparatus further comprising a receiver configured to receive a transmission from a remote site, the transmission having an power command, the transmitter gain control comprising a closed loop control configured to recover the power command from the transmission received and an open loop control configured to estimate received power of the transmission, the second gain being computed by the transmitter gain control as a function of the recovered power command and the estimated received power.

62. The apparatus of claim 61 wherein the transmitter gain control further comprising a summer configured to sum the recovered power command and the estimated received power, the second gain being a function of the summed power command and the estimated received power.

63. An apparatus, comprising:

means for receiving a first to second power ratio;

means for adjusting the power ratio if a combined power of a plurality of channels exceeds a threshold, the channels including the first and second channels; and

means for computing gain of the first channel as a function of the power ratio.

64. The apparatus of claim 63 wherein the means for adjusting the power ratio comprises means for computing the combined power of the channels as a function of the power ratio and power for the second channel, means for comparing the combined power computation to the threshold, and means for reducing the power ratio if the combined power computation exceeds the threshold.

65. The apparatus of claim 64 further comprising means for computing the power for the second channel as a function of a criterion.

66. The apparatus of claim 65 wherein the criterion comprises minimum transmission power to achieve a quality of service at a remote site.

67. The apparatus of claim 64 wherein the means for computing power for the second channel comprises means for estimating power of a received transmission from a remote site, the power for the second channel being computed as a function of estimated power.

68. The apparatus of claim 64 wherein the means for computing power for the second channel comprises means for recovering a power command from a transmission received from a remote site, the power for the second channel being computed as a function of the recovered power command.

69. The apparatus of claim 64 wherein the means for reducing the power ratio reduces the power ratio in incremental steps.

70. The apparatus of claim 64 wherein the means for reducing the power ratio computes the power ratio reduction as a function of the threshold.

75. The apparatus of claim 63 further comprising, in addition to the means for receiving the first to second channel power ratio, means for receiving a power ratio for each remaining channel with respect to the second channel, and wherein the means for computing the gain of the first channel divides the square root of the first to second channel power ratio by the square root of the sum of the first to second channel power ratio and the power ratios for each of the remaining channels.