Method and apparatus for estimating a maximum rate of data and for estimating power required for transmission of data at a rate of data in a communication system

• US 7,209,517 B2
• Filed: 03/04/2002
• Issued: 04/24/2007
• Est. Priority Date: 03/04/2002
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Black, Peter J., Sindhushayana, Nagabhushana, Attar, Rashid Ahmed
• Primary Examiner(s): Patel; Jay K.
• Assistant Examiner(s): Odom; Curtis B.
• Application Number:
  US10/090,712
• Publication Number:
  US 20030165190A1
• Time in Patent Office: 1,877 Days
• Field of Search: 375/222, 375/225, 370252-443, 455/522
• US Class Current: 375/225
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0021 in which the algorithm uses adaptive thresholds
• CPC Class Codes: H04W 52/223 predicting future states of the transmission
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/26 using transmission rate or quality of service QoS [Quality of Service]
• CPC Class Codes: H04W 52/265 taking into account the quality of service QoS
• CPC Class Codes: H04W 52/267 taking into account the information rate
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

Methods and apparatus for estimating maximum rate of data and for estimating a transmission power required for transmission of a data with a rate of data in a communication system are disclosed. A terminal determines a quality metric of a communication link, over which data are to be transmitted, and modifies the determined quality metric by a quality metric margin. The terminal then estimates the maximum rate of data in accordance with the modified quality metric. Alternatively, the terminal then estimates transmission power required for transmission of a data with a rate of data in accordance with the rate of data and the modified quality metric. The quality metric margin may be a pre-determined or dynamically adjusted. The terminal dynamically adjusts the quality metric margin in accordance with a result of comparison of a transmit power corresponding to the estimated maximum rate of data with an actual transmit power used to transmit the data.

Claims

1. A method for estimating a reverse link maximum data rate, comprising:

determining at a source of data a quality metric of a link over which data is to be transmitted wherein the quality metric is determined by;

generating an open loop estimate of the quality metric;

generating a closed loop estimate of the quality metric;

filtering the open loop estimate using a first filtering method;

filtering the closed loop estimate using a second filtering method; and

summing the filtered open loop estimate and the filtered closed loop estimate;

modifying the quality metric by a transmission power margin; and

determining a maximum rate of data in accordance with the modified quality metric.

2. The method as claimed in claim 1, wherein the first filtering method comprises:

filtering said quality metric by a linear filter.

3. The method as claimed in claim 1, wherein the first filtering method comprises:

filtering said quality metric by a non-linear filter.

4. The method as claimed in claim 3, wherein said filtering the quality metric by a non-linear filter comprises:

filtering said quality metric by a peak filter.

5. The method as claimed in claim 1, wherein determining at a source of data a quality metric of a link over which data is to be transmitted comprises:

receiving at a source of data at least one first reference signal; and

determining the quality metric in accordance with the received at least one first reference signal.

6. The method as claimed in claim 1, wherein determining at a source of data a quality metric of a link over which data is to be transmitted comprises:

receiving at a source of data a feedback signal; and

determining the quality metric in accordance with the received feedback signal.

7. The method as claimed in claim 1, wherein determining at a source of data a quality metric of a link over which data is to be transmitted comprises:

receiving at a source of data at least one signal;

receiving at a source of data a feedback signal; and

determining the quality metric in accordance with the received at least one signal and the received feedback signal.

8. The method as claimed in claim 1, wherein determining at a source of data a quality metric of a link over which data is to be transmitted comprises:

receiving at a source of data a reference signal;

receiving at a source of data a feedback signal; and

determining the quality metric in accordance with the reference signal, the received reference signal, and the received feedback signal.

9. The method as claimed in claim 1, wherein modifying the quality metric by a transmission power margin comprises:

declaring an outage event when power required for transmission of a second reference signal exceeds power required for transmission of the second reference signal determined from previously modified quality metric;

detecting occurrence of the outage event during a pre-determined interval; and

modifying the quality metric in accordance with the detecting.

10. The method as claimed in claim 9, wherein modifying the quality metric in accordance with the detecting comprises:

increasing a current transmission power margin by a first amount when a pre-determined number of the outage events occurred during the pre-determined interval; and

modifying the quality metric by the increased transmission power margin.

11. The method as claimed in claim 10, further comprising:

decreasing a current transmission power margin by a second amount when the pre-determined number of the outage events did not occur during the pre-determined interval; and

modifying the quality metric by the decreased transmission power margin.

12. The method as claimed in claim 1, wherein modifying the quality metric by a transmission power margin comprises:

declaring an outage event when power required for transmission of data at the estimated rate of data exceeds maximum allowable transmission power;

detecting occurrence of the outage event during a pre-determined interval; and

modifying the quality metric in accordance with the detecting.

13. The method as claimed in claim 12, wherein modifying the quality metric in accordance with the detecting comprises:

increasing a current transmission power margin by a first amount when a pre-determined number of outages occurred during the pre-determined interval; and

modifying the quality metric by the increased transmission power margin.

14. The method as claimed in claim 13, further comprising:

decreasing a current transmission power margin by a second amount when the pre-determined number of outages did not occur during the pre-determined interval; and

modifying the quality metric by the decreased transmission power margin.

15. The method as claimed in claim 13, wherein increasing a current transmission power margin by a first amount when a pre-determined number of outages occurred during the pre-determined interval comprises:

determining whether the estimated rate of data has changed to a maximum allowable rate of data;

setting a quality metric lower limit to the current value of the quality metric; and

increasing the quality metric by a first value when a pre-determined number of outages occurred during the pre-determined interval.

16. The method as claimed in claim 15, further comprising:

decreasing the power margin by a second value if the resulting decreased power margin is greater that the lower limit of the power margin; and

setting the power margin equal to the lower limit of the power margin otherwise.

17. The method as claimed in claim 14, wherein the decreasing a current transmission power margin by a second amount when the pre-determined number of outages did not occur during the pre-determined interval;

comprises;

determining whether the estimated rate of data is equal to a minimum allowable rate of data;

setting a quality metric upper limit to the current value of the quality metric; and

decreasing the quality metric by a first value when a pre-determined number of outages occurred during the pre-determined interval.

18. The method as claimed in claim 17, further comprising:

increasing the power margin by a second value if the resulting increased power margin is less that the lower limit of the power margin; and

setting the power margin equal to the lower limit of the power margin otherwise.

19. The method as claimed in claim 13, wherein increasing a current transmission power margin by a first amount when a pre-determined number of outages occurred during the pre-determined interval comprises:

determining whether the estimated rate of data is equal to a maximum allowable rate of data; and

increasing the quality metric by a first value when a pre-determined number of outages occurred during the pre-determined interval.

20. The method as claimed in claim 19, further comprising:

unchanging the power margin when a pre-determined number of outages did not occur during the pre-determined interval.

21. The method as claimed in claim 13, wherein decreasing a current transmission power margin by a second amount when the pre-determined number of outages did not occur during the pre-determined interval;

comprises;

determining whether the estimated rate of data is equal to a minimum allowable rate of data; and

decreasing the quality metric by a value when a pre-determined number of outages did not occur during the pre-determined interval.

22. The method as claimed in claim 17, further comprising:

leaving the power margin unchanged when a pre-determined number of outages occurred during the pre-determined interval.

23. The method as claimed in claim 1, wherein determining a maximum rate of data in accordance with the modified quality metric comprises:

determining a transmission power in accordance with the modified quality metric; and

selecting a data rate whose the determined transmission power does not exceed maximum allowable transmission power.

24. The method as claimed in claim 1, wherein the second filtering method comprises:

filtering said quality metric by a linear filter.

25. The method as claimed in claim 1, wherein the second filtering method comprises:

filtering said quality metric by a non-linear filter.

26. The method as claimed in claim 25, wherein said filtering the quality metric by a non-linear filter comprises:

filtering said quality metric by a peak filter.

27. An apparatus for estimating a reverse link maximum data rate, comprising:

means for determining at a source of data a quality metric of a link over which data is to be transmitted, wherein the means for determining the quality metric comprises;

means for generating an open loop estimate of a first quality metric;

means for generating a closed loop estimate of a second quality metric;

means for filtering the open loop estimate using a first filtering means;

means for filtering the closed loop estimate using a second filtering means; and

means for summing the filtered open loop estimate and the filtered closed loop estimate;

means for modifying the quality metric by a transmission power margin; and

means for determining a maximum rate of data in accordance with the modified quality metric.

28. The apparatus as claimed in claim 27, wherein the first filtering means comprises:

means for filtering the quality metric by a linear filter.

29. The apparatus as claimed in claim 27, wherein the second filtering means comprises:

means for filtering the quality metric by a non-linear filter.

30. The apparatus as claimed in claim 29, wherein the means for filtering the quality metric by a non-linear filter comprises:

means for filtering the quality metric by a peak filter.

31. The apparatus as claimed in claim 27, wherein the means for determining at a source of data a quality metric of a link over which data is to be transmitted comprises:

means for receiving at a source of data at least one signal; and

means for determining the quality metric in accordance with the received at least one signal.

32. The apparatus as claimed in claim 27, wherein the means for determining at a source of data a quality metric of a link over which data is to be transmitted comprises:

means for receiving at a source of data at least one first reference signal; and

means for determining the quality metric in accordance with the received at least one first reference signal.

33. The apparatus as claimed in claim 27, wherein the means for determining at a source of data a quality metric of a link over which data is to be transmitted comprises:

means for receiving at a source of data a feedback signal; and

means for determining the quality metric in accordance with the received feedback signal.

34. The apparatus as claimed in claim 27, wherein the means for determining at a source of data a quality metric of a link over which data is to be transmitted comprises:

means for receiving at a source of data at least one signal;

means for receiving at a source of data a feedback signal; and

means for determining the quality metric in accordance with the received at least one signal and the received feedback signal.

35. The apparatus as claimed in claim 27, wherein the means for determining at a source of data a quality metric of a link over which data is to be transmitted comprises:

means for receiving at a source of data a first reference signal;

means for receiving at a source of data a feedback signal; and

means for determining the quality metric in accordance with the first reference signal, the received first reference signal, and the received feedback signal.

36. The apparatus as claimed in claim 27, wherein the means for modifying the quality metric by a transmission power margin comprises:

means for modifying the quality metric by a pre-determined transmission power margin.

37. The apparatus as claimed in claim 27, wherein the means for modifying the quality metric by a transmission power margin comprises:

means for declaring an outage event when power required for transmission of a second reference signal exceeds power required for transmission of the second reference signal determined form previously modified quality metric;

means for detecting occurrence of the outage event during a pre-determined interval; and

means for modifying the quality metric in accordance with the detecting.

38. The apparatus as claimed in claim 37, wherein the means for modifying the quality metric in accordance with the detecting comprises:

means for increasing a current transmission power margin by a first amount when a pre-determined number of the outage events occurred during the pre-determined interval; and

means for modifying the quality metric by the increased transmission power margin.

39. The apparatus as claimed in claim 38, further comprising:

means for decreasing a current transmission power margin by a second amount when the pre-determined number of the outage events did not occur during the pre-determined interval; and

means for modifying the quality metric by the decreased transmission power margin.

40. The apparatus as claimed in claim 27, wherein the means for modifying the quality metric by a transmission power margin comprises:

means for declaring an outage event when power required for transmission of data at the estimated rate of data exceeds maximum allowable transmission power;

means for detecting occurrence of the outage event during a pre-determined interval; and

means for modifying the quality metric in accordance with the detecting.

41. The apparatus as claimed in claim 40, wherein the means for modifying the quality metric in accordance with the detecting comprises:

means for increasing a current transmission power margin by a first amount when a pre-determined number of outages occurred during the pre-determined interval; and

means for modifying the quality metric by the increased transmission power margin.

42. The apparatus as claimed in claim 41, further comprising:

means for decreasing a current transmission power margin by a second amount when the pre-determined number of outages did not occur during the pre-determined interval; and

means for modifying the quality metric by the decreased transmission power margin.

43. The apparatus as claimed in claim 41, wherein the means for increasing a current transmission power margin by a first amount when a pre-determined number of outages occurred during the pre-determined interval comprises:

means for determining whether the estimated rate of data has changed to a maximum allowable rate of data;

means for setting a quality metric lower limit to the current value of the quality metric; and

means for increasing the quality metric by a first value when a pre-determined number of outages occurred during the pre-determined interval.

44. The apparatus as claimed in claim 43, further comprising:

means for decreasing the power margin by a second value if the resulting decreased power margin is greater that the lower limit of the power margin; and

means for setting the power margin equal to the lower limit of the power margin otherwise.

45. The apparatus as claimed in claim 42, wherein the means for decreasing a current transmission power margin by a second amount when the predetermined number of outages did not occur during the pre-determined interval;

comprises;

means for determining whether the estimated rate of data has changed to a minimum allowable rate of data;

means for setting a quality metric upper limit to the current value of the quality metric; and

means for decreasing the quality metric by a first value when a pre-determined number of outages occurred during the pre-determined interval.

46. The apparatus as claimed in claim 45, further comprising:

means for increasing the power margin by a second value if the resulting increased power margin is less that the lower limit of the power margin; and

means for setting the power margin equal to the lower limit of the power margin otherwise.

47. The apparatus as claimed in claim 41, wherein the means for increasing a current transmission power margin by a first amount when a pre-determined number of outages occurred during the pre-determined interval comprises:

means for determining whether the estimated rate of data is equal to a maximum allowable rate of data; and

means for increasing the quality metric by a first value when a pre-determined number of outages occurred during the pre-determined interval.

48. The apparatus as claimed in claim 47, further comprising:

means for leaving the power margin unchanged when a pre-determined number of outages did not occur during the pre-determined interval.

49. The apparatus as claimed in claim 42, wherein the means for decreasing a current transmission power margin by a second amount when the pre-determined number of outages did not occur during the pre-determined interval;

comprises;

means for determining whether the estimated rate of data is equal to a minimum allowable rate of data; and

means for decreasing the quality metric by a value when a pre-determined number of outages did not occur during the pre-determined interval.

50. The apparatus as claimed in claim 49, further comprising:

means for leaving the power margin unchanged when a pre-determined number of outages occurred during the pre-determined interval.

51. The apparatus as claimed in claim 27, wherein the means for determining a maximum rate of data in accordance with the modified quality metric comprises:

means for determining a transmission power in accordance with the modified quality metric; and

means for selecting a data rate whose the determined transmission power does not exceed maximum allowable transmission power.

52. The apparatus as claimed in claim 27, wherein the first filtering means comprises:

means for filtering the quality metric by a linear filter.

53. The apparatus as claimed in claim 27, wherein the second filtering means comprises:

means for filtering the quality metric by a non-linear filter.

54. The apparatus as claimed in claim 53, wherein the means for filtering the quality metric by a non-linear filter comprises:

means for filtering the quality metric by a peak filter.