Systems and methods for detecting radar signals

Patent metadata

Field	Value
Publication number	US-9304189-B2
Application number	US-201314089236-A
Country	US
Kind code	B2
Filing date	Nov 25, 2013
Priority date	Mar 8, 2013
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

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.

First claim

What is claimed is:

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
determine 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 greater than a current channel 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 greater than a current channel 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

Assignees

• Qualcomm Inc
• Qualcomm Inc

Inventors

• Rezk Meriam Khufu Ragheb
• Mosko Richard
• Yucek Tevfik
• Chadd Adrian Harold

Classifications

• H04K3/226

  Selection of non-jammed channel for communication (spectrum sharing arrangements H04W16/14; selection of wireless resources by user or terminal H04W72/02) · CPC title

• H04K3/822

  by detecting the presence of a surveillance, interception or detection · CPC title

• H04K2203/18

  for wireless local area networks or WLAN · CPC title

• G01S7/021 Primary

  Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals · CPC title

• H04B1/1027

  assessing signal quality or detecting noise/interference for the received signal · CPC title