System and method for optimized power control

• US 6,259,928 B1
• Filed: 09/30/1998
• Issued: 07/10/2001
• Est. Priority Date: 10/13/1997
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Vembu, Sridhar
• Primary Examiner(s): TO, DORIS HA
• Application Number:
  US09/164,384
• Time in Patent Office: 1,014 Days
• Field of Search: 455/422, 455/522, 455/69, 455/70, 455/127, 370/318
• US Class Current: 455/522
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 52/20 using error rate
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets

Abstract

A system and method for optimizing power control provides dynamic adjustment of a power-control threshold thereby allowing transmitter power to be reduced when signal quality is high. In a communication system having at least one mode for controlling the power of a transmitter in the communication system, the threshold level of the system is optimized by determining performance of the communication system based on a predetermined metric such as the system error rate, for example. Additionally, the power of the transmitter or transmitted signal in relation to the threshold of the communication system is determined. The threshold of the communication system is adjusted based on the performance of the communication system and the power of the transmitter in relation to the threshold.

Claims

1. A method for adjusting a threshold level in a communication system having at least one mode for controlling the power of a transmitter in the communication system during system operation, comprising the steps of:

determining performance of the communication system based on a predetermined metric;

determining the power of the transmitter in the communication system in relation to the threshold of the communication; and

adjusting a value of the threshold based on said performance of the communication system and the power of the transmitter in relation to said threshold.

2. The method of claim 1, wherein said step of adjusting comprises the step of increasing said threshold of the communication system when the system is operating at or near threshold, and the performance of the system is below acceptable levels.

3. The method of claim 1, wherein said step of adjusting comprises the step of decreasing the threshold of the communication system when the system is operating at or near threshold and the performance of the system is above acceptable levels.

4. The method of claim 1, wherein said predetermined metric is one of the group of error rate of the system, frame error rate, number of consecutive frame errors, and bit error rate.

5. The method of claim 1, wherein said step of determining performance of the communication system further comprises the step of determining whether a parameter of the communication system is within a defined range.

6. The system of claim 5, wherein said parameter is chosen from the group comprising signal-to-noise ratio, received signal strength, frame error rate frequency, number of consecutive frame errors, and bit-error rate.

7. The method of claim 5, further comprising the step of selecting modes of power control based on said determination of said parameter being within a range.

8. The method of claim 7, further comprising the step of adjusting the power of the transmitter according to a selected power control mode of the communication system.

9. The method of claim 8, wherein said adjustments in power are incremental power increases.

10. The method of claim 7, wherein said step of selecting modes of power control is performed at the transmitter.

11. The method of claim 7, wherein said step of selecting modes of power control is performed at a receiver location and further comprises a step of transmitting a command from the receiver location to the transmitter to select a desired power control mode.

21. The method of claim 1, wherein

said step of determining the power comprises determining whether the system is operating at or near threshold, and

said adjusting step comprises adjusting the value of the threshold based on an outcome of said step of determining whether the system is operating at or near threshold.

22. The method of claim 1, wherein said adjusting step comprises the steps of:

adjusting the value of the threshold when said system is operating at or near threshold and the performance of the system is one of above and below acceptable levels; and

otherwise

maintaining the value of the threshold.

23. The method of claim 1, further comprising the step of:

maintaining the value of the threshold when said performance of the system is below acceptable levels and the system is not operating at or near threshold.

24. The method of claim 1, further comprising the step of:

maintaining the value of the threshold when said performance of the system is below acceptable levels and the system is operating at or near threshold.

25. The method of claim 1, wherein said adjusting step comprises the steps of:

adjusting the value of the threshold when

said system is operating at or near threshold and the performance of the system is one of above and below acceptable levels,

said system is operating below threshold and the performance of the system is one of above and at acceptable levels, and

said system is operating above threshold and the performance of the system is one of below and at acceptable levels; and

otherwise

maintaining the value of the threshold.

12. Apparatus for adjusting a threshold level in a communication system having at least one mode for controlling the power of a transmitter in the communication system during system operation, comprising:

means for determining performance of the communication system based on a predetermined metric;

means for determining a power of the transmitter in the communication system in relation to said threshold; and

means for adjusting a value of the threshold based on said performance of the communication system and the power of the transmitter in relation to said threshold.

13. The apparatus of claim 12, wherein said performance of the communication system is measured according to one or more of the group comprising signal-to-noise ratio, received signal strength, frame error rate frequency, number of consecutive frame errors, and bit-error rate.

14. The apparatus of claim 12, wherein said means for determining performance of the communication system comprises means for determining whether a transmitted signal is at, above or below a threshold level.

15. The apparatus of claim 12, wherein said means for determining performance of the communication system comprises means for determining whether a parameter of the communication system is within a defined range.

16. The apparatus of claim 15, wherein said parameter is chosen from the group comprising signal-to-noise ratio, received signal strength, frame error rate frequency, number of consecutive frame errors, and bit-error rate.

17. The apparatus of claim 15, further comprising means for selecting modes of power control based on said determination of said parameter being within a range.

18. The apparatus of claim 17, further comprising means for adjusting the power of the transmitter according to a selected power control mode of the communication system.

19. The apparatus of claim 17, wherein said means for selecting modes of power control is located at the transmitter.

20. The apparatus of claim 17, wherein said means for selecting modes of power control is located at a receiver location and further comprising means for transmitting a command from the receiver location to the transmitter to select a desired power control mode.

26. The apparatus of claim 12, wherein said power determining means is adapted to determine whether the system is operating at or near threshold, and said means for adjusting is adapted to adjust the value of the threshold based on an output of said power determining means indicating whether the system is operating at or near threshold.

27. The apparatus of claim 12, wherein said adjusting means is adapted to:

adjust the value of the threshold when said system is operating at or near threshold and the performance of the system is one of above and below acceptable levels, and otherwise

maintain the value of the threshold.

28. The apparatus of claim 12, further comprising:

means for maintaining the value of the threshold when said performance of the system is below acceptable levels and the system is not operating at or near threshold.

29. The apparatus of claim 12, further comprising:

means for maintaining the value of the threshold when said performance of the system is below acceptable levels and the system is operating at or near threshold.

30. The apparatus of claim 12, wherein said adjusting means is adapted to adjust the value of the threshold when

said system is operating at or near threshold and the performance of the system is one of above and below acceptable levels,

said system is operating below threshold and the performance of the system is one of above and at acceptable levels, and

said system is operating above threshold and the performance of the system is one of below and at acceptable levels, and otherwise

maintain the value of the threshold.