Systems and Methods for SIR Estimation for Power Control

• US 20090291642A1
• Filed: 05/23/2008
• Published: 11/26/2009
• Est. Priority Date: 05/23/2008
• Status: Abandoned Application

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Cozzo, Carmela, Edholm, Christer, He, Ning
• Application Number:
  US12/126,240
• Publication Number:
  US 20090291642A1
• Time in Patent Office: Days
• US Class Current: 455/67.13
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo

Abstract

Systems and methods according to these exemplary embodiments provide for methods and systems for improving the signal-to-interference-plus-noise ratio (SIR) estimation between a mobile communications device and a base station (BS) for improving power control. A first SIR estimate is generated based on signals received on at least a first channel and a second SIR estimate is generated based on signals received on a second channel. A correction factor for the second SIR estimate is generated based on at least the first SIR estimate, and the second SIR estimate is adjusted with the correction factor. The first SIR estimate can, optionally, be generated using channel coefficients generated from signals received on both the first channel and the second channel.

Claims

1. A method for estimating a signal-to-interference-plus-noise ratio (SIR) for use in power control comprising:

generating a first SIR estimate based on signals received on at least a first channel;

generating a second SIR estimate based on signals received on a second channel;

generating a correction factor for said second SIR estimate based on at least said first SIR estimate; and

adjusting said second SIR estimate with said correction factor.

2. The method of claim 1, further comprising:

comparing said adjusted second SIR estimate with a SIR target value; and

adjusting an uplink transmit power control command based on said comparison.

3. The method of claim 1, further comprising:

scaling said first SIR estimate with a first scaling factor; and

scaling said second SIR estimate with a second scaling factor.

4. The method of claim 3, wherein said first and second scaling factors are each a number between 0 and 1 inclusive, further wherein a sum of said first and second scaling factors equals

5. The method of claim 1, wherein said correction factor is calculated using at least said first SIR estimate and a ratio associated with transmit powers of said first channel and said second channel.

6. The method of claim 1, wherein said correction factor is calculated using said first SIR estimate and said second SIR estimate, and a ratio associated with transmit powers of said first channel and said second channel.

7. The method of claim 1, wherein said signals received on at least a first channel includes signals received on both said first channel and said second channel.

8. The method of claim 1, wherein said first SIR estimate and said second SIR estimate are determined at the same rate and wherein said first SIR estimate is generated using detected symbols.

9. The method of claim 1, wherein said first SIR estimate and said second SIR estimate are determined at different rates and wherein said first SIR estimate is generated based upon decoded symbols or bits.

10. The method of claim 1, wherein said second channel is a dedicated physical control channel and said first channel is an enhanced dedicated physical control channel.

11. The method of claim 1, wherein said step of generating a first SIR estimate based on signals received on at least a first channel further comprises:

using channel estimates from both said first channel and said second channel to generate said first SIR estimate.

12. The method of claim 1, wherein said step of adjusting further comprises:

adjusting said second SIR estimate with said correction factor only when a transmit power of said first channel relative to a transmit power of said second channel is equal to or greater than a predetermined threshold.

13. A device comprising:

a communications interface for receiving signals; and

a processor which uses said received signals to;

generate a first SIR estimate based on signals received on at least a first channel;

generate a second SIR estimate based on signals received on a second channel;

generate a correction factor for said second SIR estimation based on at least said first SIR estimate; and

adjust said second SIR estimate with said correction factor.

14. The device of claim 13, wherein said device is a one of a base station and a NodeB.

15. The device of claim 13, wherein said processor further compares said adjusted second SIR estimate with a SIR target value;

and adjusts an uplink transmit power control command based on said comparison.

16. The device of claim 13, wherein said processor further scales said first SIR estimate with a first scaling factor;

and scales said second SIR estimate with a second scaling factor.

17. The device of claim 16, wherein said first and second scaling factors are each a number between 0 and 1 inclusive, further wherein a sum of said first and second scaling factors equals 1.

18. The device of claim 13, wherein said correction factor is calculated using at least said first SIR estimate and a ratio associated with transmit powers of said first channel and said second channel.

19. The device of claim 13, wherein said correction factor is calculated using said first SIR estimate and said second SIR estimate, and a ratio associated with transmit powers of said first channel and said second channel.

20. The device of claim 13, wherein said signals received on at least a first channel includes signals received on both said first channel and said second channel.

21. The device of claim 13, wherein said first SIR estimate and said second SIR estimate are determined by said processor at the same rate and wherein said first SIR estimate is generated using detected symbols.

22. The device of claim 13, wherein said first SIR estimate and said second SIR estimate are determined by said processor at different rates and wherein said first SIR estimate is generated based upon decoded symbols or bits.

23. The device of claim 13, wherein said processor uses channel estimates from both said first channel and said second channel to generate said first SIR estimate.

24. The device of claim 13, wherein said processor adjusts said second SIR estimate with said correction factor only when a transmit power of said first channel relative to a transmit power of said second channel is equal to or greater than a predetermined threshold.

25. The device of claim 13, wherein said second channel is a dedicated physical control channel and said first channel is an enhanced dedicated physical control channel.