Method for enhanced power control by adaptively adjusting an amount of change in a target signal-to-noise ratio

• US 6,791,954 B1
• Filed: 06/12/2000
• Issued: 09/14/2004
• Est. Priority Date: 06/12/2000
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Salvarini, Alexandro Federico, Jiang, Frances, Huang, Ching Yao, Cheng, Terry Si-Fong
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US09/592,287
• Time in Patent Office: 1,555 Days
• Field of Search: 370/311, 370/318, 370/331, 370/332, 370/333, 370/335, 455/522
• US Class Current: 370/311
• CPC Class Codes: H04W 52/125 cascaded outer loop power control
• CPC Class Codes: H04W 52/20 using error rate
• CPC Class Codes: H04W 52/225 Calculation of statistics, e.g. average, variance
• 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

In the method according to the present invention, a signal from a mobile station is received. The standard deviation of the symbol error rate is determined, and power control with adaptive adjustment of an amount of change in the target signal-to-noise ratio is performed based on the determined standard deviation of the signal error rate and a target associated therewith.

Claims

1. A method for use in a wireless infrastructure, comprising:

receiving a signal from a transmitting device;

determining symbol error rates based on said received signal; and

performing reverse outer loop power control with adaptive adjustment of an amount of change in a target signal-to-noise ratio, said adaptive adjustment based on said symbol error rates.

2. The method of claim 1, wherein said adaptive adjustment is based on said symbol error rates and a target associated with said symbol error rates.

3. The method of claim 1, wherein said adaptive adjustment is triggered by determination of a frame error rate.

4. The method of claim 1, further comprising:

determining frame error rates based on said received signal; and

wherein

said adaptive adjustment adjusts said target signal-to-noise ratio by an amount based on said frame error rates and said symbol error rates.

5. The method of claim 1, further comprising:

determining frame error rates from said received signal;

determining whether to increase or decrease said target signal-to-noise ratio based on said frame error rates; and

determining an amount to increase or decrease said target signal-to-noise ratio based on said symbol error rates.

6. A method for use in a wireless infrastructure, comprising:

receiving a signal from a transmitting device;

first determining a standard deviation of a symbol error rates based on said received signal; and

performing power control with adaptive adjustment of an amount of change in a target signal-to-noise ratio based on said standard deviation of said symbol error rates.

7. The method of claim 6, wherein said adaptive adjustment adjusts said target signal-to-noise ratio by an amount based on said standard deviation of said symbol error rates and a target standard deviation of said symbol error rates.

8. The method of claim 7, further comprising:

second determining frame error rates from said received signal; and

third determining whether to increase or decrease said target standard deviation of said symbol error rates based on said frame error rates.

9. The method of claim 8, wherein said third determining step comprises:

fourth determining if communication quality is acceptable based on said frame error rates;

fifth determining if communication quality is acceptable based on said standard deviation of said symbol error rates and said target standard deviation of said symbol error rates; and

decreasing said target standard deviation of said symbol error rates if said output of said fourth determining step indicates unacceptable communication quality and said output of said fifth determining step indicates acceptable communication quality; and

increasing said target standard deviation of said symbol error rates if said output of said fourth determining step indicates unacceptable communication quality and said output of said fifth determining step indicates acceptable communication quality.

10. The method of claim 9, further comprising:

first determining if communication quality is acceptable based on said frame error rates;

second determining if communication quality is acceptable based on said standard deviation of said symbol error rates and said target standard deviation of said symbol error rates; and

adjusting said target standard deviation of said symbol error rates consistent with output of said first determining step when said output of said first determining step and output of said second determining step are inconsistent.

11. The method of claim 6, further comprising:

determining frame error rates based on said received signal; and

wherein

said adaptive adjustment adjusts said target signal-to-noise ratio by an amount based on said frame error rates, said standard deviation of said symbol error rates, and a target standard deviation of said symbol error rates.

12. The method of claim 6, further comprising:

determining frame error rates based on said received signal; and

wherein said performing step includes,

first determining if communication quality is acceptable based on a frame error rates,

second determining if communication quality is acceptable based on said standard deviation of said symbol error rates and a target standard deviation of said symbol error rates,

increasing said target signal-to-noise ratio by a first amount if said output of said first determining step indicates unacceptable communication quality and said output of said second determining step indicates acceptable communication quality,

increasing said target signal-to-noise ratio by a second amount, which is based on said standard deviation of said symbol error rates and said target standard deviation of said symbol error rates, if said output of said first determining step indicates unacceptable communication quality and said output of said second determining step indicates unacceptable communication quality,

decreasing said target signal-to-noise ratio by a third amount if said output of said first determining step indicates acceptable communication quality and said output of said second determining step indicates unacceptable communication quality, and

decreasing said target signal-to-noise ratio by a fourth amount, which is based on said standard deviation of said symbol error rates and said target standard deviation of said symbol error rates, if said output of said first determining step indicates acceptable communication quality and said output of said second determining step indicates acceptable communication quality.

13. The method of claim 12, further comprising:

decreasing said target standard deviation of said symbol error rates if said output of said first determining step indicates unacceptable communication quality and said output of said second determining step indicates acceptable communication quality; and

increasing said target standard deviation of said symbol error rates if said output of said first determining step indicates unacceptable communication quality and said output of said second determining step indicates acceptable communication quality.

14. A method for use in a wireless infrastructure, comprising:

receiving a signal from a transmitting device; and

performing power control which is triggered by determination of frame error rates and which adaptively adjusts a target signal-to-noise ratio based on determined symbol error rates, said frame error rates and said symbol error rates determined based on said received signal.

15. The method of claim 14, wherein said performing step comprises:

determining said frame error rates and symbol error rates from said received signal;

determining a standard deviation of said symbol error rates; and

adaptively adjusting a target signal-to-noise ratio based on said standard deviation of said symbol error rates.

16. The method of claim 15, wherein said performing step comprises:

determining a frame error rates and a symbol error rates from said received signal;

determining whether to increase or decrease said target signal-to-noise ratio based on said frame error rates; and

determining an amount to increase or decrease said target signal-to-noise ratio based on said symbol error rates.