METHOD AND APPARATUS FOR NON-LINE-OF-SIGHT DETECTION AND CODED RADAR SIGNALS

• US 20200132826A1
• Filed: 10/28/2019
• Published: 04/30/2020
• Est. Priority Date: 10/26/2018
• Status: Active Grant

• Current Assignee: Metawave Corporation (Xerox Holdings Corp.)
• Original Assignee: Metawave Corporation (Xerox Holdings Corp.)
• Inventors: Achour, Maha
• Granted Patent: US 11,474,230 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 13/536 using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves
• CPC Class Codes: G01S 13/538 eliminating objects that have not moved between successive antenna scans, e.g. area MTi
• CPC Class Codes: G01S 13/931 of land vehicles

Abstract

Radar systems are disclosed to detect objects in non-line-of-sight (“NLOS”) areas. A clutter signature is used to determine a location and motion of an object.

Claims

1. A method for object detection, comprising:

transmitting a sounding signal;

determining a clutter signature based on the sounding signal;

transmitting an object detection signal;

receiving a return object detection signal;

determining a return time of the object detection signal;

determining a location of a detected object by using the return time;

filtering out the clutter signature from the return object detection signal;

producing a filtered return object detection signal based on the filtering; and

extracting motion of the detected object by using the filtered return object detection signal.

2. The method of object detection as in claim 1, further comprising:

receiving a return sounding signal; and

determining the clutter signature from the return sounding signal.

3. The method of object detection as in claim 1, wherein the determining of the return time of the object detection signal comprises comparing a time of transmission of the object detection signal to a time of receipt of the return object detection signal.

4. The method of object detection as in claim 1, wherein the determining of the location of the detected object comprises identifying the detected object as a non-line of sight object, if the return time exceeds a maximum time threshold.

5. The method as in claim 1, wherein the clutter signature identifies where stationary objects are located.

6. The method as in claim 5, further comprising using a clutter delay spread to update the clutter signature.

7. The method as in claim 1, further comprising detecting interference using frequency hopping.

8. The method as in claim 7, further comprising avoiding the interference using frequency hopping.

9. The method as in claim 1, wherein the transmitting of the sounding signal comprises scanning a radar beam.

10. The method as in claim 9, wherein the radar beam is scanned over a short-range area.

11. The method as in claim 1, wherein the object detection signal comprises a frequency-modulated carrier-wave.

12. The method as in claim 11, wherein the frequency-modulated carrier-wave comprises a sawtooth waveform.

13. The method as in claim 1, wherein the method is performed by a radar sensing unit.

14. The method as in claim 13, wherein the radar sensing unit is employed in a vehicle.

15. A radar sensing unit, comprising:

a sounding signal module for transmitting a sounding signal to determine a clutter signature;

a memory unit storing the clutter signature;

a radar controller generating, controlling, and interpreting an object detection signal;

a transmit antenna unit coupled to the radar controller, adapted to transmit the object detection signal;

a receive antenna unit coupled to the radar controller, adapted to receive a return object detection signal; and

a non-line of sight module coupled to the transmit antenna unit and the receive antenna unit adapted to;

determine a location of a detected object by using a return time of the object detection signal;

filter out the clutter signature from the return object detection signal to produce a filtered return object detection signal; and

extract motion of the detected object by using the filtered return object detection signal.

16. The radar sensing unit as in claim 15, wherein the radar sensing unit is employed in a vehicle.

17. The radar sensing unit as in claim 15, wherein the object detection signal comprises a frequency-modulated carrier-wave.

18. The radar sensing unit as in claim 17, wherein the frequency-modulated carrier-wave comprises a sawtooth waveform.

19. The radar sensing unit as in claim 15, wherein the clutter signature identifies where stationary objects are located.

20. A system for object detection, comprising:

a transmit antenna to transmit a sounding signal and an object detection signal;

a receive antenna to receive a return sounding signal and a return object detection signal;

a sounding signal module to determine a clutter signature based on the return sounding signal; and

a non-line of sight module to;

determine a return time of the object detection signal;

determine a location of a detected object by using the return time;

filter out the clutter signature from the return object detection signal to produce a filtered return object detection signal; and

extract motion of the detected object by using the filtered return object detection signal.