Method and arrangement for noise variance and sir estimation

• US 20070207741A1
• Filed: 08/05/2004
• Published: 09/06/2007
• Est. Priority Date: 08/07/2003
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: IPWireless Inc. (NVIDIA Corporation)
• Inventors: Jones, Alan
• Granted Patent: US 7,590,388 B2
• Time in Patent Office: Days
• US Class Current: 455/67.130
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]

Abstract

A method and arrangement for noise variance and SIR estimation in a UTRAN Node B or User Equipment estimates the SIR (SIR⁽¹⁾ . . . SIR^(K)) at the output of a detector by using an estimate ({circumflex over (σ)}²) of the detector input noise variance to provide an estimate ({circumflex over (σ)}²) of the detector output noise variance. The detector input noise variance is derived from a midamble portion in the received signal. By deriving the transfer function of the detector an estimate of the detector output noise variance is estimated. The estimated output noise variance then allows an improved estimate of the SIR (SIR⁽¹⁾ . . . SIR^(K)) at the detected output.

Claims

1. A method for noise variance estimation of a detected signal, the method comprising:

receiving a signal and producing therefrom in a detector a detected signal;

producing from the received signal a first noise variance signal representative of noise variance in the received signal; and

producing from the detected signal and the first noise variance signal a second noise variance signal representative of noise variance estimation in the received signal.

2. The method of claim 1, wherein the step of producing the second noise variance signal comprises applying a function equal to the detector'"'"'s transfer function to the first noise variance signal.

3. The method of claim 1, wherein the step of producing the first noise variance signal comprises deriving the first noise variance signal from a midamble portion of the received signal.

4. The method of claim 1, further comprising:

producing from the second noise variance signal and an estimate of total power at the detector output a signal-to-interference ratio (SIR) signal representative of SIR in the received signal.

5. The method of claim 1 wherein the detector is a CDMA multi-user detector.

6. The method of claim 1, wherein the detector is a CDMA single-user detector.

7. The method of claim 1, wherein the detector comprises a CDMA RAKE receiver.

8. The method of claim 1, wherein the received signal is a wireless signal.

9. The method of claim 8, wherein the wireless signal is a UMTS air interface signal.

10. A user equipment capable of noise variance estimation of a detected signal, the user equipment comprising:

a detector for receiving a signal and detecting therein a detected signal;

first noise variance logic for producing from the received signal a first noise variance signal representative of noise variance in the received signal; and

second noise variance logic for producing from the detected signal and the first noise variance signal a second noise variance signal representative of noise variance estimation in the received signal.

11. The user equipment of claim 10, wherein the second noise variance logic is arranged to apply a function equal to the detector'"'"'s transfer function to the first noise variance signal to produce the second noise variance signal.

12. The user equipment of claim 10, wherein the first noise variance logic is arranged to derive the first noise variance signal from a midamble portion of the received signal.

13. The user equipment of claim 10, further comprising:

signal-to-interference ratio (SIR) estimation logic for producing from the second noise variance signal and an estimate of total power at the detector output an SIR signal representative of SIR in the received signal.

14. The user equipment of claim 10, wherein the detector is a CDMA multi-user detector.

15. The user equipment of claim 10, wherein the detector is a CDMA single-user detector.

16. The user equipment of claim 10, wherein the detector comprises a CDMA RAKE receiver.

18. The user equipment of claim 10, wherein the received signal is a UMTS air interface signal.

17. (canceled)

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26. A base station capable of noise variance estimation of a detected signal, the base station:

a detector for receiving a signal and detecting therein a detected signal;

first noise variance logic for producing from the received signal a first noise variance signal representative of noise variance in the received signal; and

second noise variance logic for producing from the detected signal and the first noise variance signal a second noise variance signal representative of noise variance estimation in the received signal.

27. The base station of claim 26, wherein the second noise variance logic is arranged to apply a function equal to the detector'"'"'s transfer function to the first noise variance signal to produce the second noise variance signal.

28. The base station of claim 26, wherein the first noise variance logic is arranged to derive the first noise variance signal from a midamble portion of the received signal.

29. The base station of claim 26, further comprising:

SIR estimation logic for producing from second noise variance signal and an estimate of total power at the detector output an SIR signal representative of SIR in the received signal.

30. The base station of claim 26, wherein the detector is a CDMA multi-user detector.

31. The base station of claim 26, wherein the detector is a CDMA single-user detector.

32. The base station of claim 26, wherein the detector comprises a CDMA RAKE receiver.

33. The base station of claim 26, wherein the received signal is a UMTS air interface signal.

34. A user equipment comprising:

a memory;

a processor coupled to the memory; and

program code executable on the processor, the program code operable for;

receiving a signal and producing therefrom in a detector a detected signal;

producing from the received signal a first noise variance signal representative of noise variance in the received signal; and

producing from the detected signal and the first noise variance signal a second noise variance signal representative of noise variance estimation in the received signal.

35. A base station comprising:

a memory;

a processor coupled to the memory; and

program code executable on the processor, the program code operable for;

receiving a signal and producing therefrom in a detector a detected signal;

producing from the received signal a first noise variance signal representative of noise variance in the received signal; and

producing from the detected signal and the first noise variance signal a second noise variance signal representative of noise variance estimation in the received signal.

36. A computer program product comprising program code for noise variance estimation of a detected signal, the computer program product comprising program code for:

receiving a signal and producing therefrom in a detector a detected signal;

producing from the received signal a first noise variance signal representative of noise variance in the received signal; and

producing from the detected signal and the first noise variance signal a second noise variance signal representative of noise variance estimation in the received signal.

37. The computer program product of claim 36, wherein the program code is further operable for:

applying a function equal to the detector'"'"'s transfer function to the first noise variance signal.

38. The computer program product of claim 36, wherein the program code is further operable for deriving the first noise variance signal from a midamble portion of the received signal.

39. The computer program product of claim 36, wherein the program code is further operable for producing from the second noise variance signal and an estimate of total power at the detector output an SIR signal representative of SIR in the received signal.

40. A communication system arranged to provide for noise variance estimation of a detected signal, the communication system comprising:

a detector for receiving a signal and detecting therein a detected signal;

first noise variance logic for producing from the received signal a first noise variance signal representative of noise variance in the received signal; and

second noise variance logic for producing from the detected signal and the first noise variance signal a second noise variance signal representative of noise variance estimation in the received signal.

41. An integrated circuit for receiving a signal and detecting therein a detected signal, the integrated circuit comprising:

first noise variance means for producing from the received signal a first noise variance signal representative of noise variance in the received signal; and

second noise variance means for producing from the detected signal and the first noise variance signal a second noise variance signal representative of noise variance estimation in the received signal.