Methods for detecting and classifying signals transmitted over a radio frequency spectrum

• US 8,755,754 B2
• Filed: 10/24/2012
• Issued: 06/17/2014
• Est. Priority Date: 08/15/2007
• Status: Active Grant

• Current Assignee: Shared Spectrum Company
• Original Assignee: Shared Spectrum Company
• Inventors: McHenry, Mark A., Dain, Dmitry, Steadman, Karl, Ritterbush, Olga, Livsis, Eugene
• Primary Examiner(s): Barron, Jr., Gilberto
• Assistant Examiner(s): Cribbs, Malcolm
• Application Number:
  US13/658,968
• Publication Number:
  US 20130072128A1
• Time in Patent Office: 601 Days
• Field of Search: None
• US Class Current: 455/67.11
• CPC Class Codes: H04B 1/719 Interference-related aspects
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 17/391 Modelling the propagation channel
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition

Abstract

A method for classifying a signal is disclosed. The method can be used by a station or stations within a network to classify the signal as non-cooperative (NC) or a target signal. The method performs classification over channels within a frequency spectrum. The percentage of power above a first threshold is computed for a channel. Based on the percentage, a signal is classified as a narrowband signal. If the percentage indicates the absence of a narrowband signal, then a lower second threshold is applied to confirm the absence according to the percentage of power above the second threshold. The signal is classified as a narrowband signal or pre-classified as a wideband signal based on the percentage. Pre-classified wideband signals are classified as a wideband NC signal or target signal using spectrum masks.

Claims

1. A method of classifying a cooperative target signal within a channel by a dynamic spectrum access device, said method comprising:

selecting a channelization for a spectrum region of interest;

dividing a channel identified by the channelization into a plurality of bins, wherein the size of the channel is selected to correspond to an expected size of a target cooperative signal;

measuring energy detected by a detector within the plurality of bins;

determining a degree of correlation between the measured energy and a target signal channel mask; and

upon determining that the degree of correlation between the measured energy and the channel mask is above a correlation threshold, classifying the received energy as a target cooperative signal.

2. A method as recited in claim 1, wherein the size of each of the plurality of bins is determined by a resolution of the detector.

3. A method as recited in claim 1, further comprising a step of selecting the target signal channel mask from a plurality of signal masks.

4. A method as recited in claim 1, further comprising determining the probability that the received energy comprises a target cooperative signal.

5. A method as recited in claim 1, wherein the channelization identifies a plurality of channels.

6. A method as recited in claim 5, wherein at least one channel identified by the channelization at least partially overlaps at least one other channel identified by the channelization.

7. A method as recited in claim 1, further comprising a step of determining that the energy in the signal is a narrowband signal.

8. A method as recited in claim 1, wherein the step of determining the degree of correlation between the measured energy and a target signal channel mask comprises evaluating at least one metric selected from the group consisting of:

an area of the mask that corresponds to the measured energy, a mean of the measured energy and the mask, a variance of the measured energy and the mask, a peak-to-mean ratio of the measured energy, and a proximity to a noise floor of the measured energy.

9. A method of classifying a non-cooperative signal within a channel by a dynamic spectrum access device, said method comprising:

selecting a channelization for a spectrum region of interest;

dividing a channel identified by the channelization into a plurality of bins, wherein the size of the channel is selected to correspond to an expected size of a target cooperative signal;

measuring energy detected by a detector within the plurality of bins;

determining a degree of correlation between the measured energy and a target signal channel mask; and

upon determining that the degree of correlation between the measured energy and the channel mask is below a correlation threshold, classifying the received energy as a non-cooperative signal.

10. A method as recited in claim 9, wherein the size of each of the plurality of bins is determined by a resolution of the detector.

11. A method as recited in claim 9, further comprising a step of selecting the target signal channel mask from a plurality of signal masks.

12. A method as recited in claim 9, further comprising determining the probability that the received energy comprises a target cooperative signal.

13. A method as recited in claim 9, wherein the channelization identifies a plurality of channels.

14. A method as recited in claim 13, wherein at least one channel identified by the channelization at least partially overlaps at least one other channel identified by the channelization.

15. A method as recited in claim 9, further comprising a step of determining that the energy in the signal is a narrowband signal.

16. A method as recited in claim 9, wherein the step of determining the degree of correlation between the measured energy and a target signal channel mask comprises evaluating at least one metric selected from the group consisting of:

an area of the mask that corresponds to the measured energy, a mean of the measured energy and the mask, a variance of the measured energy and the mask, a peak-to-mean ratio of the measured energy, and a proximity to a noise floor of the measured energy.

17. A dynamic spectrum access device comprising:

a detector configured to measure energy within a plurality of bins, the plurality of bins being with a channel identified by a channelization for a spectrum region of interest, wherein the size of the channel is selected to correspond to an expected size of a target cooperative signal; and

a processor configured to;

determine a degree of correlation between the measured energy and a target signal channel mask; and

upon determining that the degree of correlation between the measured energy and the channel mask is above a correlation threshold, classify the received energy as a target cooperative signal.

18. A device as recited in claim 17, said processor further configured to select the channelization for the spectrum region of interest and to divide the channel identified by the channelization into the plurality of bins.

19. A device as recited in claim 17, wherein the size of each of the plurality of bins is determined by a resolution of the detector.

20. A device as recited in claim 17, said processor further configured to select the target signal channel mask from a plurality of signal masks.

21. A device as recited in claim 17, said processor further configured to determine the probability that the received energy comprises a target cooperative signal.

22. A device as recited in claim 17, wherein the channelization identifies a plurality of channels.

23. A device as recited in claim 22, wherein at least one channel identified by the channelization at least partially overlaps at least one other channel identified by the channelization.

24. A device as recited in claim 17, said processor further configured to determine that the energy in the signal is a narrowband signal.

25. A device as recited in claim 17, wherein, to determine the degree of correlation between the measured energy and a target signal channel mask, said processor is further configured to evaluate at least one metric selected from the group consisting of:

an area of the mask that corresponds to the measured energy, a mean of the measured energy and the mask, a variance of the measured energy and the mask, a peak-to-mean ratio of the measured energy, and a proximity to a noise floor of the measured energy.

26. A method of classifying a cooperative target signal within a channel by a dynamic spectrum access device, said method comprising:

selecting a channelization for a spectrum region of interest, wherein at least one channel identified by the channelization at least partially overlaps at least one other channel identified by the channelization;

dividing a channel identified by the channelization into a plurality of bins;

measuring energy detected by a detector within the plurality of bins;

determining a degree of correlation between the measured energy and a target signal channel mask; and

upon determining that the degree of correlation between the measured energy and the channel mask is above a correlation threshold, classifying the received energy as a target cooperative signal.

27. A method as recited in claim 26, wherein the size of each of the plurality of bins is determined by a resolution of the detector.

28. A method as recited in claim 26, further comprising a step of selecting the target signal channel mask from a plurality of signal masks.

29. A method as recited in claim 26, further comprising determining the probability that the received energy comprises a target cooperative signal.

30. A method as recited in claim 26, further comprising a step of determining that the energy in the signal is a narrowband signal.

31. A method as recited in claim 26, wherein the step of determining the degree of correlation between the measured energy and a target signal channel mask comprises evaluating at least one metric selected from the group consisting of:

an area of the mask that corresponds to the measured energy, a mean of the measured energy and the mask, a variance of the measured energy and the mask, a peak-to-mean ratio of the measured energy, and a proximity to a noise floor of the measured energy.

32. A method of classifying a non-cooperative signal within a channel by a dynamic spectrum access device, said method comprising:

selecting a channelization for a spectrum region of interest, wherein at least one channel identified by the channelization at least partially overlaps at least one other channel identified by the channelization;

dividing a channel identified by the channelization into a plurality of bins;

measuring energy detected by a detector within the plurality of bins;

determining a degree of correlation between the measured energy and a target signal channel mask; and

upon determining that the degree of correlation between the measured energy and the channel mask is below a correlation threshold, classifying the received energy as a non-cooperative signal.

33. A method as recited in claim 32, wherein the size of each of the plurality of bins is determined by a resolution of the detector.

34. A method as recited in claim 32, further comprising a step of selecting the target signal channel mask from a plurality of signal masks.

35. A method as recited in claim 32, further comprising determining the probability that the received energy comprises a target cooperative signal.

36. A method as recited in claim 32, further comprising a step of determining that the energy in the signal is a narrowband signal.

37. A method as recited in claim 32, wherein the step of determining the degree of correlation between the measured energy and a target signal channel mask comprises evaluating at least one metric selected from the group consisting of:

an area of the mask that corresponds to the measured energy, a mean of the measured energy and the mask, a variance of the measured energy and the mask, a peak-to-mean ratio of the measured energy, and a proximity to a noise floor of the measured energy.

38. A dynamic spectrum access device comprising:

a detector configured to measure energy within a plurality of bins, the plurality of bins being with a channel identified by a channelization for a spectrum region of interest, wherein at least one channel identified by the channelization at least partially overlaps at least one other channel identified by the channelization; and

a processor configured to;

determine a degree of correlation between the measured energy and a target signal channel mask; and

upon determining that the degree of correlation between the measured energy and the channel mask is above a correlation threshold, classify the received energy as a target cooperative signal.

39. A device as recited in claim 38, said processor further configured to select the channelization for the spectrum region of interest and to divide the channel identified by the channelization into the plurality of bins.

40. A device as recited in claim 39, wherein the size of each of the plurality of bins is determined by a resolution of the detector.

41. A device as recited in claim 38, said processor further configured to select the target signal channel mask from a plurality of signal masks.

42. A device as recited in claim 38, said processor further configured to determine the probability that the received energy comprises a target cooperative signal.

43. A device as recited in claim 38, said processor further configured to determine that the energy in the signal is a narrowband signal.

44. A device as recited in claim 38, wherein, to determine the degree of correlation between the measured energy and a target signal channel mask, said processor is further configured to evaluate at least one metric selected from the group consisting of:

an area of the mask that corresponds to the measured energy, a mean of the measured energy and the mask, a variance of the measured energy and the mask, a peak-to-mean ratio of the measured energy, and a proximity to a noise floor of the measured energy.