Spectrum sensing of bluetooth using a sequence of energy detection measurements

• US 8,964,692 B2
• Filed: 11/05/2009
• Issued: 02/24/2015
• Est. Priority Date: 11/10/2008
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Shellhammer, Stephen J., Van Nee, Richard
• Primary Examiner(s): Vu, Huy D
• Assistant Examiner(s): Beyen, Zewdu A
• Application Number:
  US12/612,749
• Publication Number:
  US 20100118695A1
• Time in Patent Office: 1,937 Days
• Field of Search: None
• US Class Current: 370/331
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals

Abstract

Certain aspects of the present disclosure provide techniques for detecting presence of a Bluetooth device in the vicinity of a WiFi device by sensing the spectrum of the Bluetooth device using a sequence of energy detection measurements, generating a test statistic based on the measurements and comparing the test statistic to a threshold.

Claims

1. A method for detecting the presence, in a first radio access technology (RAT) network, of a device that communicates via a second RAT, comprising:

estimating a plurality of received power values of transmissions via the second RAT at a plurality of time steps during a network quiet time of the first RAT network to generate a first set of received power values;

calculating a first test statistic based on the first set of received power values, wherein the first test statistic comprises a mean of a plurality of a selected received power values of the first set of received power values having the highest values;

comparing, by a processor, the first test statistic with a first threshold to determine if the device that communicates via the second RAT is in range; and

in response to determining the device that communicates via the second RAT is in range, switching from a first operational frequency to a second operational frequency.

2. The method of claim 1, wherein the first RAT is in compliance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11n standard.

3. The method of claim 1, wherein the second RAT is in compliance with the Institute of Electrical and Electronics Engineers (IEEE) 802.15.1 (Bluetooth) standard.

4. The method of claim 1, wherein the first operational frequency corresponds to a 40 MHz bandwidth and the second operational frequency corresponds to a 20 MHz bandwidth.

5. The method of claim 1, further comprising:

calculating a second test statistic based on the first set of received power values; and

comparing the second test statistic with a second threshold.

6. The method of claim 5, further comprising:

declaring presence of the device that communicates via the second RAT in range if the first test statistic is larger than the first threshold and the second test statistic is larger than the second threshold.

7. The method of claim 5, further comprising:

declaring a false alarm if the first test statistic is larger than the first threshold but the second test statistic is equal to or smaller than the second threshold.

8. The method of claim 1, further comprising:

estimating a plurality of received power values of transmissions via the second RAT at a plurality of time steps during another network quiet time of the first RAT to generate a second set of received power values, if the device that communicates via the second RAT was previously in range;

calculating a third test statistic based on the second set of received power values; and

comparing the third test statistic with a third threshold to determine if the device that communicates via the second RAT is no longer within range, wherein the third threshold is smaller than the first threshold.

9. The method of claim 8, further comprising:

in response to detecting the device that communicates via the second RAT is no longer within range, switching from the second operational frequency back to the first operational frequency.

10. The method of claim 5, wherein the second test statistic is based on a time domain correlation of the received power values.

11. An apparatus for detecting the presence, in a first radio access technology (RAT) network, of a device that communicates via a second RAT, comprising:

means for estimating a plurality of received power values of transmissions via the second RAT at a plurality of time steps during a network quiet time of the first RAT network to generate a first set of received power values;

means for calculating a first test statistic based on the first set of received power values, wherein the first test statistic comprises a mean of a plurality of a selected received power values of the first set of received power values having the highest values;

means for comparing the first test statistic with a first threshold to determine if the device that communicates via the second RAT is in range; and

means for switching from a first operational frequency to a second operational frequency in response to determining the device that communicates via the second RAT is in range.

12. The apparatus of claim 11, wherein the first RAT is in compliance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11n standard.

13. The apparatus of claim 11, wherein the second RAT is in compliance with the Institute of Electrical and Electronics Engineers (IEEE) 802.15.1 (Bluetooth) standard.

14. The apparatus of claim 11, wherein the first operational frequency corresponds to a 40 MHz bandwidth and the second operational frequency corresponds to a 20 MHz bandwidth.

15. The apparatus of claim 11, further comprising:

means for calculating a second test statistic based on the first set of received power values; and

means for comparing the second test statistic with a second threshold.

16. The apparatus of claim 15, further comprising:

means for declaring presence of the device that communicates via the second RAT in range if the first test statistic is larger than the first threshold and the second test statistic is larger than the second threshold.

17. The apparatus of claim 15, further comprising:

means for declaring a false alarm if the first test statistic is larger than the first threshold but the second test statistic is equal or smaller than the second threshold.

18. The apparatus of claim 11, further comprising:

means for estimating a plurality of received power values of transmissions via the second RAT at a plurality of time steps during another network quiet time of the first RAT to generate a second set of received power values, if the device that communicates via the second RAT was previously in range;

means for calculating a third test statistic based on the second set of received power values; and

means for comparing the third test statistic with a third threshold to determine if the device that communicates via the second RAT is no longer within range, wherein the third threshold is smaller than the first threshold.

19. The apparatus of claim 18, further comprising:

in response to detecting the device that communicates via the second RAT is no longer within range, means for switching from the second operational frequency back to the first operational frequency.

20. The apparatus of claim 11, wherein the means for comparing the first test statistic with a first threshold to determine if the device that communicates via the second RAT is in range comprises a processor.

21. An apparatus for detecting the presence, in a first radio access technology (RAT) network, of a device that communicates via a second RAT, comprising:

at least one processor configured to;

estimate a plurality of received power values of transmissions via the second RAT at a plurality of time steps during a network quiet time of the first RAT network to generate a first set of received power values;

calculate a first test statistic based on the first set of received power values, wherein the first test statistic comprises a mean of a plurality of a selected received power values of the first set of received power values having the highest values;

compare the first test statistic with a first threshold to determine if the device that communicates via the second RAT is in range; and

switch from a first operational frequency to a second operational frequency in response to determining the device that communicates via the second RAT is in range; and

a memory coupled to the at least one processor.

22. The apparatus of claim 21, wherein the first RAT is in compliance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11n standard.

23. The apparatus of claim 21, wherein the second RAT is in compliance with the Institute of Electrical and Electronics Engineers (IEEE) 802.15.1 (Bluetooth) standard.

24. The apparatus of claim 21, wherein the first operational frequency corresponds to a 40 MHz bandwidth and the second operational frequency corresponds to a 20 MHz bandwidth.

25. The apparatus of claim 21, wherein the processor is further configured to:

calculate a second test statistic based on the first set of received power values; and

compare the second test statistic with a second threshold.

26. The apparatus of claim 25, wherein the processor is further configured to:

declare presence of the device that communicates via the second RAT in range if the first test statistic is larger than the first threshold and the second test statistic is larger than the second threshold.

27. The apparatus of claim 25, wherein the processor is further configured to:

declare a false alarm if the first test statistic is larger than the first threshold but the second test statistic is equal or smaller than the second threshold.

28. The apparatus of claim 21, wherein the processor is further configured to:

estimate a plurality of received power values of transmissions via the second RAT at a plurality of time steps during another network quiet time of the first RAT to generate a second set of received power values, if the device that communicates via the second RAT was previously in range;

calculate a third test statistic based on the second set of received power values; and

compare the third test statistic with a third threshold to determine if the device that communicates via the second RAT is no longer within range, wherein the third threshold is smaller than the first threshold.

29. The apparatus of claim 28, wherein the processor is further configured to:

in response to detecting the device that communicates via the second RAT is no longer within range, switch from the second operational frequency back to the first operational frequency.

30. The apparatus of claim 25, wherein the second test statistic is based on a time domain correlation of the received power values.

31. A non-transitory computer readable medium for detecting the presence, in a first radio access technology (RAT) network, of a device that communicates via a second RAT, the computer readable medium having instructions stored thereon, the instructions being executable by one or more processors and the instructions comprising:

instructions for estimating a plurality of received power values of transmissions via the second RAT at a plurality of time steps during a network quiet time of the first RAT network to generate a first set of received power values;

instructions for calculating a first test statistic based on the first set of received power values, wherein the first test statistic comprises a mean of a plurality of a selected received power values of the first set of received power values having the highest values;

instructions for comparing the first test statistic with a first threshold to determine if the device that communicates via the second RAT is in range; and

instructions for switching from a first operational frequency to a second operational frequency in response to determining the device that communicates via the second RAT is in range.

32. The computer readable medium of claim 31, wherein the first RAT is in compliance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11n standard.

33. The computer readable medium of claim 31, wherein the second RAT is in compliance with the Institute of Electrical and Electronics Engineers (IEEE) 802.15.1 (Bluetooth) standard.

34. The computer readable medium of claim 31, wherein the first operational frequency corresponds to a 40 MHz bandwidth and the second operational frequency corresponds to a 20 MHz bandwidth.

35. The computer readable medium of claim 31, further comprising:

instructions for calculating a second test statistic based on the first set of received power values; and

instructions for comparing the second test statistic with a second threshold.

36. The computer readable medium of claim 35, further comprising:

instructions for declaring presence of the device that communicates via the second RAT in range if the first test statistic is larger than the first threshold and the second test statistic is larger than the second threshold.

37. The computer readable medium of claim 35, further comprising:

instructions for declaring a false alarm if the first test statistic is larger than the first threshold but the second test statistic is equal or smaller than the second threshold.

38. The computer readable medium of claim 31, further comprising:

instructions for estimating a plurality of received power values of transmissions via the second RAT at a plurality of time steps during another network quiet time of the first RAT to generate a second set of received power values, if the device that communicates via the second RAT was previously in range;

instructions for calculating a third test statistic based on the second set of received power values; and

instructions for comparing the third test statistic with a third threshold to determine if the device that communicates via the second RAT is no longer within range, wherein the third threshold is smaller than the first threshold.

39. The computer readable medium of claim 38, further comprising:

in response to detecting the device that communicates via the second RAT is no longer within range, instructions for switching from the second operational frequency back to the first operational frequency.

40. The computer readable medium of claim 35, wherein the second test statistic is based on a time domain correlation of the received power values.