OPERATING ENVIRONMENT ANALYSIS TECHNIQUES FOR WIRELESS COMMUNICATION SYSTEMS

• US 20090052570A1
• Filed: 10/13/2005
• Published: 02/26/2009
• Est. Priority Date: 10/13/2004
• Status: Active Grant

• Current Assignee: Mcmaster University
• Original Assignee: Mcmaster University
• Inventors: Haykin, Simon
• Granted Patent: US 8,224,254 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0062 Avoidance of ingress interference, e.g. ham radio channels
• CPC Class Codes: H04W 52/265 taking into account the quality of service QoS

Abstract

Methods and systems of analyzing an operating environment of wireless communication equipment in a wireless communication system are provided. A stimulus in the operating environment at a location of the wireless communication equipment is sensed and linearly expanded in Slepian sequences using a multitaper spectral estimation procedure. A singular value decomposition is performed on the linearly expanded stimulus, and a singular value of the linearly expanded stimulus provides an estimate of interference at the location of the wireless communication equipment.

Claims

1. A method of analyzing an operating environment of wireless communication equipment in a wireless communication system, comprising:

sensing a stimulus in the operating environment at a location of the wireless communication equipment;

linearly expanding the stimulus in Slepian sequences using a multitaper spectral estimation procedure; and

performing a singular value decomposition on the linearly expanded stimulus, a singular value of the linearly expanded stimulus providing an estimate of interference at the location of the wireless communication equipment.

3. The method of claim 1 or claim 2, wherein sensing comprises sensing a stimulus at each of M sensors, and wherein linearly expanding comprises determining elements of a spatio-temporal complex-valued matrix

4. The method of claim 3, wherein performing comprises performing a singular value decomposition on the matrix A(f) to thereby yield the decomposition

5. The method of claim 4, wherein |σ

₀(f)|² or a linear combination of multiple largest |σ

_k(f)|² provides the estimate of interference.

7. The method of claim 5, further comprising:

computing a time-frequency distribution of interference estimates for the location of the wireless communication equipment by repeating the steps of sensing, linearly expanding, and performing for a plurality of bursts of operation.

8. The method of claim 7, further comprising:

determining

9. The method of claim 8, wherein determining further comprises determining whether fluctuations in D(t) subsequent to the reduction are less than a further threshold for a subsequent burst, and wherein detecting comprises detecting a spectrum hole where a reduction in D(t) from one burst to a next burst exceeds the threshold and fluctuations in D(t) subsequent to the reduction are less than the further threshold.

10. The method of claim 1, further comprising:

detecting, based on the estimate of interference, a spectrum hole in which resources are available for transmission of communication signals by a transmitter; and

selecting the detected spectrum hole for transfer of communication signals.

13. The method of claim 10, further comprising:

repeating the sensing, linearly expanding, and performing;

detecting a further spectrum hole; and

selecting the further spectrum hole for transfer of communication signals.

14. The method of claim 13, further comprising:

transferring communication signals using both the selected spectrum hole and the further spectrum hole.

15. The method of claim 13, further comprising:

predicting subsequent availability of the selected spectrum hole; and

selecting the further spectrum hole for transfer of communication signals where the selected spectrum hole is predicted to become unavailable.

16. The method of claim 15, wherein the predicting is based on historical communication traffic patterns for the selected spectrum hole.

19. The method of claim 1, further comprising:

transmitting the estimate of interference to a transmitter of communication signals.

20. A machine-readable medium storing instructions which when executed perform the method of claim 1.

2. (canceled)

6. (canceled)

11-12. -12. (canceled)

17-18. -18. (canceled)

21. A system for analyzing an operating environment of wireless communication equipment in a wireless communication system, comprising:

an input for receiving a stimulus in the operating environment at a location of the wireless communication equipment; and

a processor operatively coupled to the input and configured to linearly expand the stimulus in Slepian sequences using a multitaper spectral estimation procedure, and to perform a singular value decomposition on the linearly expanded stimulus, a singular value of the linearly expanded stimulus providing an estimate of interference at the location of the wireless communication equipment.

22. The system of claim 21, wherein the processor is further configured to implement a cognitive radio.

23. The system of claim 21, further comprising:

a plurality of antennas; and

a transceiver operatively coupled to the plurality of antennas and to the input.

24. The system of claim 23, wherein the processor is further configured to output to the transceiver the estimate of interference, and wherein the transceiver is configured to transmit the estimate of interference to other communication equipment.

25. The system of claim 21, further comprising:

M sensors, each sensor being for sensing a stimulus, wherein the processor is configured to linearly expand the stimuli sensed by the sensors by determining elements of a spatio-temporal complex-valued matrix

26. The system of claim 25, wherein the processor is configured to perform a singular value decomposition by performing a singular value decomposition on the matrix A(f) to thereby yield the decomposition

27. The system of claim 26, wherein |σ

₀(f)|² or a linear combination of multiple largest |σ

_k(f)|² provides the estimate of interference.

29. The system of claim 27, wherein the input receives a stimulus at the location of the wireless communication equipment for a plurality of bursts of operation.

30. The system of claim 29, wherein the processor is further configured to determine

31. The system of claim 30, wherein the processor is further configured to determine whether fluctuations in D(t) subsequent to the reduction are less than a further threshold for a subsequent burst, and to detect a spectrum hole where a reduction in D(t) from one burst to a next burst exceeds the threshold and fluctuations in D(t) subsequent to the reduction are less than the further threshold.

32. The system of claim 21, wherein the processor is further configured to detect, based on the estimate of interference, a spectrum hole in which resources are available for transmission of communication signals by a transmitter and to select the detected spectrum hole for transfer of communication signals.

35. The system of claim 32, wherein the processor is further configured to monitor the operating environment to detect a further spectrum hole, and to select the further spectrum hole for transfer of communication signals.

36. The system of claim 35, wherein the processor is further configured to cause communication signals to be transferred using both the selected spectrum hole and the further spectrum hole.

37. The system of claim 35, wherein the processor is further configured to predict subsequent availability of the selected spectrum hole, and to select the further spectrum hole for transfer of communication signals where the selected spectrum hole is predicted to become unavailable.

38. The system of claim 37, wherein the processor is configured to predict availability of the selected spectrum hole based on historical communication traffic patterns for the selected spectrum hole.

28. (canceled)

33-34. -34. (canceled)

39-42. -42. (canceled)