Method and apparatus for non-line-of-sight detection and coded radar signals

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

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

receiving a return sounding signal, wherein

the clutter signature is determined based further on the return sounding signal.

3. The method 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 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 one or more 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 , where 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, wherein the short-range area is an area covered by the radar beam.

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 radar controller configured for generating, controlling, and interpreting an object detection signal, the radar controller comprising a sounding signal module and a non-line of sight module, the sounding signal module configured for generating and transmitting a sounding signal to determine a clutter signature;

a memory configured for storing the clutter signature;

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

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

wherein the non-line of sight module is coupled to the transmit antenna unit and the receive antenna unit, the non-line of sight module 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 one or more stationary objects are located.

20. A system for object detection, comprising:

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

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

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

a non-line of sight module configured to determine a return time of the object detection signal, to determine a location of a detected object by using the return time, to filter out the clutter signature from the return object detection signal to produce a filtered return object detection signal, and to extract motion of the detected object by using the filtered return object detection signal.