Detecting Presence/Absence of an Information Signal

• US 20090222401A1
• Filed: 09/11/2006
• Published: 09/03/2009
• Est. Priority Date: 09/19/2005
• Status: Active Grant

• Current Assignee: Conversant Wireless Licensing S.à.r.l. (f/k/a Core Wireless Licensing S.a.r.l.) (Conversant Intellectual Property Management, Inc. (f/k/a MOSAID Technologies))
• Original Assignee: Conversant Wireless Licensing S.à.r.l. (f/k/a Core Wireless Licensing S.a.r.l.) (Conversant Intellectual Property Management, Inc. (f/k/a MOSAID Technologies))
• Inventors: Lobo, Nativadade Albert
• Granted Patent: US 9,755,790 B2
• Time in Patent Office: Days
• US Class Current: 706/53
• CPC Class Codes: H04B 17/26 using historical data, averaging values or statistics
• CPC Class Codes: H04L 1/20 using signal quality detector

Abstract

A method including receiving inputs; determining an expected variance of the inputs; and testing a first hypothesis that the inputs include a signal.

Claims

1. A method for detecting a presence of an information signal comprising:

receiving inputs;

determining an expected variance of the received inputs; and

testing, using the determined expected variance of the received inputs, a first hypothesis that the received inputs include an information signal to detect a presence of the information signal.

2. A method as claimed in claim 1, wherein the inputs are power values.

3. A method as claimed in claim 1, further comprising using a mean of the inputs to determine algebraically the expected variance of the inputs.

4. A method as claimed in claim 3, wherein the algebraic determination is based upon an assumption of chi-squared distribution for the inputs.

5. A method as claimed in claim 3, further comprising adding a multiple of the mean of the inputs to a predetermined constant to determine the expected variance of the inputs.

6. A method as claimed in claim 5, further comprising adding to a previous expected variance of the inputs a multiple of the mean of the inputs and a predetermined constant to determine the current expected variance of the inputs.

7. A method as claimed in claim 1 comprising using inputs in an algebraic expression to obtain the expected variance of the outputs.

8. A method as claimed in claim 1, further comprising using the expected variance in the inputs to determine algebraically the expected variance in the mean of the inputs.

9. A method as claimed in claim 1, further comprising testing a first hypothesis that the inputs includes an information signal.

10. A method as claimed in claim 1, further comprising determining whether a range of probable values for the mean of the inputs lies above a threshold.

11. A method as claimed in claim 10, wherein the range is a constant number of standard deviations from the mean of the inputs.

12. A method as claimed in claim 10, wherein the range is a decreasing number of standard deviations from the mean of the inputs.

13. A method as claimed in claim 10, wherein the threshold is a constant.

14. A method as claimed in claim 10, wherein the threshold is dependent upon an upper boundary of the range of probable values for the mean of the inputs if they do not include a signal.

15. A method as claimed in claim 1, further comprising testing a second hypothesis that the inputs do not include an information signal.

16. A method as claimed in claim 1, further comprising determining whether a range of probable values for the mean of the inputs lies below a threshold.

17. A method as claimed in claim 15, wherein the range is a constant number of standard deviations from the mean of the inputs.

18. A method as claimed in claim 15, wherein the threshold is a constant.

19. A method as claimed in claim 17, wherein the constant is the expected mean of the inputs if there is no signal.

20. A method as claimed in claim 1, wherein the signal is cyclostationary.

21. A method as claimed in claim 1, wherein the signal has a mean of zero.

24. A computer program comprising program instructions for causing a computer to perform the method of claim 1.

22. A decision engine comprising:

means for determining an expected variance of received inputs; and

means for testing, using the determined expected variance of the received inputs, a first hypothesis that the inputs include an information signal to detect a presence of the information signal.

25. A physical entity embodying the computer program as claimed in claim 22.

23. A computer program comprising computer program instructions which when loaded into a processor enable the processor to:

determine an expected variance of received inputs; and

test, using the determined expected variance of the received inputs, a first hypothesis that the received inputs include an information signal to detect a presence of the information signal.

26. A detector comprising:

means for determining an expected variance of received inputs; and

means for testing, using the determined expected variance of the received inputs, a first hypothesis that the received inputs include an information signal to detect a presence of the information signal.

27. An apparatus comprising:

a device configured to receive inputs;

processing circuitry, for detecting a presence of an information signal within the received inputs, configured to determine an expected variance of the received inputs and to test, using the determined expected variance of the received inputs, a first hypothesis that the received inputs include an information signal.

28. An apparatus as claimed in claim 27 wherein the operation of the processing circuitry is controlled by computer program instructions.

29. An apparatus as claimed in claim 27 wherein the processing circuitry is dedicated hardware.

30. An apparatus as claimed in claim 27, wherein the received inputs are

dependent upon received cdma radio signals.

31. An apparatus as claimed in claim 27, wherein the received inputs are non-coherently integrated power values for received radio signals.