SYSTEMS AND METHODS FOR DETECTING RADAR SIGNALS

• US 20140253361A1
• Filed: 11/25/2013
• Published: 09/11/2014
• Est. Priority Date: 03/08/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: YUCEK, Tevfik, REZK, Meriam Khufu Ragheb, MOSKO, Richard
• Granted Patent: US 9,304,189 B2
• Time in Patent Office: Days
• US Class Current: 342/16
• CPC Class Codes: G01S 7/021 Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04K 2203/18 for wireless local area networks or WLAN
• CPC Class Codes: H04K 3/226 Selection of non-jammed channel for communication spectrum sharing arrangements H04W16/14; selection of wireless resources by user or terminal H04W72/02
• CPC Class Codes: H04K 3/822 by detecting the presence of a surveillance, interception or detection

Abstract

This disclosure includes systems and methods for detecting radar signals by performing an initial spectral analysis to identify candidate radar signals and subsequently determining whether any candidate radar signals are false detections using a secondary analysis.

Claims

1. A wireless communications device configured to detect radar signals, comprising:

a receiver having a Fast Fourier Transform (FFT) unit for receiving an incoming signal, wherein the FFT unit generates a first FFT capture including a signal magnitude for a plurality of frequency bins; and

a radar unit configured to;

perform an initial signal analysis on the first FFT capture;

identify a candidate radar signal based at least in part on whether the signal magnitude of at least one of the frequency bins exceeds an initial threshold;

perform a secondary signal analysis on the incoming signal; and

determining the candidate radar signal is a false detection based at least in part on the secondary signal analysis.

2. The wireless communications device of claim 1, wherein the FFT unit is further configured to generate a second FFT capture of the incoming signal including a signal magnitude for a plurality of frequency bins, wherein the first FFT capture is performed at a first resolution, the second FFT capture is performed at a second resolution and the second resolution is higher than the first resolution and wherein the radar unit performs the secondary signal analysis using the second FFT capture.

3. The wireless communications device of claim 2, wherein the radar unit determines the candidate radar signal is a false detection based at least in part on the signal magnitude of at least one of the frequency bins of the second FFT capture exceeding a secondary threshold.

4. The wireless communications device of claim 2, wherein the FFT unit is further configured to generate at least one subsequent FFT capture of the incoming signal and wherein the radar unit performs the secondary signal analysis using the subsequent FFT capture to supersede the second FFT capture.

5. The wireless communications device of claim 1, wherein the radar unit performs the secondary signal analysis by determining a location of a frequency bin having a maximal signal magnitude in relation to a wireless channel at which the receiver is operating and wherein the radar unit determines the candidate radar signal is a false detection based at least in part on the frequency bin having the maximal signal magnitude being located at a band edge of the wireless channel.

6. The wireless communications device of claim 1, wherein the FFT unit is configured to generate the first FFT capture over an increased bandwidth and wherein the radar unit performs the secondary signal analysis by determining a location of a frequency bin having a maximal signal magnitude in relation to a boundary of a wireless channel at which the receiver is operating.

7. The wireless communications device of claim 6, wherein the radar unit determines the candidate radar signal is a false detection based at least in part on the frequency bin having the maximal signal magnitude being located outside the wireless channel.

8. The wireless communications device of claim 7, wherein the radar unit further determines the candidate radar signal is a false detection based at least in part on a frequency bin within the wireless channel having a maximal signal magnitude not exceeding a secondary threshold.

9. The wireless communications device of claim 1, wherein the radar unit is further configured to detect a radio frequency (RF) saturation event, wherein the radar unit performs the secondary signal analysis by determining a maximal signal magnitude of a frequency bin and wherein the radar unit determines the candidate radar signal is a false detection based at least in part on the maximal signal magnitude of the frequency bin does not exceed a saturation threshold, wherein the saturation threshold is greater than the initial threshold.

10. A method for detecting a radar signal, comprising:

receiving an incoming wireless signal at a receiver;

generating a first Fast Fourier Transform (FFT) capture including a signal magnitude for a plurality of frequency bins of the incoming wireless signal;

performing an initial signal analysis on the first FFT capture;

identifying a candidate radar signal based at least in part on whether the signal magnitude of at least one of the frequency bins exceeds an initial threshold;

performing a secondary signal analysis on the incoming wireless signal; and

determining the candidate radar signal is a false detection based at least in part on the secondary signal analysis.

11. The method of claim 10, further comprising generating a second FFT capture of the incoming wireless signal including a signal magnitude for a plurality of frequency bins, wherein the first FFT capture is performed at a first resolution, the second FFT capture is performed at a second resolution and the second resolution is higher than the first resolution and wherein performing secondary signal analysis comprises using the second FFT capture.

12. The method of claim 11, wherein determining the candidate radar signal is a false detection is based at least in part on the signal magnitude of at least one of the frequency bins of the second FFT capture exceeding a secondary threshold.

13. The method of claim 11, further comprising generating at least one subsequent FFT capture of the incoming wireless signal and wherein performing secondary signal analysis comprises superseding the second FFT capture with the subsequent FFT capture.

14. The method of claim 10, wherein performing secondary signal analysis comprises determining a location of a frequency bin having a maximal signal magnitude in relation to a wireless channel at which the receiver is operating and wherein determining the candidate radar signal is a false detection is based at least in part on the frequency bin having the maximal signal magnitude being located at a band edge of the wireless channel.

15. The method of claim 10, wherein generating the first FFT capture comprises generating an FFT capture over an increased bandwidth and wherein performing secondary signal analysis comprises determining a location of a frequency bin having a maximal signal magnitude in relation to a boundary of a wireless channel at which the receiver is operating.

16. The method of claim 15, wherein determining the candidate radar signal is a false detection is based at least in part on the frequency bin having the maximal signal magnitude being located outside the wireless channel.

17. The method of claim 16, wherein determining the candidate radar signal is a false detection is based at least in part on a frequency bin within the wireless channel having a maximal signal magnitude not exceeding a secondary threshold.

18. The method of claim 10, further comprising detecting a radio frequency (RF) saturation event, wherein performing secondary signal analysis comprises determining a maximal signal magnitude of a frequency bin and wherein determining the candidate radar signal is a false detection is based at least in part on the maximal signal magnitude of the frequency bin not exceeding a saturation threshold, wherein the saturation threshold is greater than the initial threshold.

19. A non-transitory processor-readable storage medium for detecting radar signals with a wireless communications device, the processor-readable storage medium having instructions thereon, when executed by a processor to cause the wireless communications device to:

receive an incoming wireless signal at a receiver;

generate a first Fast Fourier Transform (FFT) capture including a signal magnitude for a plurality of frequency bins of the incoming wireless signal;

perform an initial signal analysis on the first FFT capture;

identify a candidate radar signal based at least in part on whether the signal magnitude of at least one of the frequency bins exceeds an initial threshold;

perform a secondary signal analysis on the incoming wireless signal; and

determine the candidate radar signal is a false detection based at least in part on the secondary signal analysis.

20. The storage medium of claim 19, having further instructions thereon to cause the wireless communications device to generate a second FFT capture of the incoming wireless signal including a signal magnitude for a plurality of frequency bins, wherein the first FFT capture is performed at a first resolution, the second FFT capture is performed at a second resolution and the second resolution is higher than the first resolution and wherein the instructions to cause the wireless communications device to perform secondary signal analysis comprise instructions to use the second FFT capture.

21. The storage medium of claim 20, wherein the instructions to cause the wireless communications device to determine the candidate radar signal is a false detection include instructions to determine the signal magnitude of at least one of the frequency bins of the second FFT capture exceeds a secondary threshold.

22. The storage medium of claim 20, having further instructions thereon to cause the wireless communications device to generate at least one subsequent FFT capture of the incoming wireless signal and wherein the instructions to cause the wireless communications device to perform secondary signal analysis comprise instructions to supersede the second FFT capture with the subsequent FFT capture.

23. The storage medium of claim 19, wherein the instructions to cause the wireless communications device to perform secondary signal analysis comprise instructions to determine a location of a frequency bin having a maximal signal magnitude in relation to a wireless channel at which the receiver is operating and wherein the instructions to cause the wireless communications device to determine the candidate radar signal is a false detection include instructions to determine the frequency bin having the maximal signal magnitude is located at a band edge of the wireless channel.

24. The storage medium of claim 19, wherein the instructions to cause the wireless communications device to generate the first FFT capture comprise instructions to generate an FFT capture over an increased bandwidth and wherein the instructions to cause the wireless communications device to perform secondary signal analysis comprise instructions to determine a location of a frequency bin having a maximal signal magnitude in relation to a boundary of a wireless channel at which the receiver is operating.

25. The storage medium of claim 24, wherein the instructions to cause the wireless communications device to determine the candidate radar signal is a false detection include instructions to determine the frequency bin having the maximal signal magnitude is located outside the wireless channel.

26. The storage medium of claim 25, wherein the instructions to cause the wireless communications device to determine the candidate radar signal is a false detection include instructions to determine a frequency bin within the wireless channel having a maximal signal magnitude does not exceed a secondary threshold.

27. The storage medium of claim 19, having further instructions thereon to cause the wireless communications device to detect a radio frequency (RF) saturation event, wherein the instructions to cause the wireless communications device to perform secondary signal analysis comprise instructions to determine a maximal signal magnitude of a frequency bin and wherein the instructions to cause the wireless communications device to determine the candidate radar signal is a false detection include instructions to determine the maximal signal magnitude of the frequency bin does not exceed a saturation threshold, wherein the saturation threshold is greater than the initial threshold.