Techniques for using matched filtering in coherent LiDAR systems

1. A method in a light detection and ranging (LiDAR) system, comprising:

receiving a return signal from a target based on an optical beam from an optical source;

sampling the return signal and converting the return signal to a frequency domain, wherein the return signal comprises a first frequency waveform;

selecting a matched filter comprising a second frequency waveform to match the first frequency waveform, wherein the second frequency waveform is determined based on an estimation of a power spectrum density function of the received signal;

updating the matched filter by updating a set of coefficients of the second frequency waveform; and

filtering the return signal by the updated matched filter to generate a filtered return signal to extract range and velocity information of the target.

2. The method of claim 1 , wherein selecting a matched filter comprises selecting a rectangular waveform, a sinc waveform, a sinc squared waveform, or a Gaussian waveform to be the second frequency waveform.

3. The method of claim 1 , wherein the set of coefficients are updated according to at least one of an angular speed of a scanning mirror, a position of the scanning mirror, a geometry of an optical scanner, or the target.

4. The method of claim 1 , wherein the set of coefficients are updated such that a filter bandwidth is proportional to at least one of an angular speed of a scanning mirror, a scanning mirror size, or a beam diameter.

5. The method of claim 1 , wherein the set of coefficients are updated based on a change in a hardware configuration or a system operation including a change of a mirror angular speed or a scan pattern change.

6. The method of claim 1 , further comprising inputting the filtered received signal into a peak selection process to extract the range and velocity information.

7. The method of claim 1 , wherein the second frequency waveform is determined based on a model or a simulation or a measurement of an optical sub-system of the LiDAR system.

8. A light detection and ranging (LiDAR) system, comprising:

a memory;

a processor, operatively coupled with the memory, to:

receive a return signal from a target based on an optical beam from an optical source;

sample the return signal and converting the return signal to a frequency domain, wherein the return signal comprises a first frequency waveform;

select a matched filter comprising a second frequency waveform to match the first frequency waveform, wherein the second frequency waveform is determined based on an estimation of a power spectrum density function of the received signal;

update the matched filter by updating a set of coefficients of the second frequency waveform; and

filter the return signal by the updated matched filter to generate a filtered return signal to extract range and velocity information of the target.

9. The LiDAR system of claim 8 , wherein the second frequency waveform comprises a rectangular waveform, a sinc waveform, a sinc squared waveform, or a Gaussian waveform to be the second frequency waveform.

10. The LiDAR system of claim 8 , wherein the set of coefficients are updated according to at least one of an angular speed of a scanning mirror, a position of the scanning mirror, a geometry of an optical scanner, or the target.

11. The LiDAR system of claim 8 , wherein the set of coefficients are updated such that a filter bandwidth is proportional to at least one of an angular speed of a scanning mirror, a scanning mirror size, or a beam diameter.

12. The LiDAR system of claim 8 , wherein the set of coefficients are updated based on a change in a hardware configuration or a system operation including a change of a mirror angular speed or a scan pattern change.

13. The LiDAR system of claim 8 , wherein the processor operatively coupled with the memory is further to input the filtered received signal into a peak selection process to extract the range and velocity information.

14. The LiDAR system of claim 8 , wherein the second frequency waveform is determined based on a model or a simulation or a measurement of an optical sub-system of the LiDAR system.

15. A non-transitory machine-readable medium having instructions stored therein, which when executed by a processor of a light detection and ranging (LiDAR) system, cause the processor to:

receive a return signal from a target based on an optical beam from an optical source;

sample the return signal and converting the return signal to a frequency domain, wherein the return signal comprises a first frequency waveform;

select a matched filter comprising a second frequency waveform to match the first frequency waveform, wherein the second frequency waveform is determined based on an estimation of a power spectrum density function of the received signal;

update the matched filter by updating a set of coefficients of the second frequency waveform; and

filter the return signal by the updated matched filter to generate a filtered return signal to extract range and velocity information of the target.

16. The non-transitory machine-readable medium of claim 15 , wherein the set of coefficients are updated according to at least one of an angular speed of a scanning mirror, a position of the scanning mirror, a geometry of an optical scanner, or the target.

17. The non-transitory machine-readable medium of claim 15 , wherein the set of coefficients are updated such that a filter bandwidth is proportional to at least one of an angular speed of a scanning mirror, a scanning mirror size, or a beam diameter.

18. The non-transitory machine-readable medium of claim 15 , wherein the set of coefficients are updated based on a change in a hardware configuration or a system operation including a change of a mirror angular speed or a scan pattern change.