Methods and systems for detecting and mitigating automotive radar interference

1. A method comprising:

receiving electromagnetic signals propagating in an environment via a radar unit coupled to a vehicle, wherein a field of view of the radar unit limits the electromagnetic signals received to a particular angle of arrival and a polarization of one or more reception antennas of the radar unit limits the electromagnetic signals received to a particular polarization;

applying a set of filters to the electromagnetic signals to remove first portions of the electromagnetic signals that are outside an expected time range and an expected frequency range, wherein the expected time range and the expected frequency range depend on radar signal transmission parameters used by the radar unit; and

removing, by a computing device, second portions of the electromagnetic signals that are indicative of spikes and plateaus associated with signal interference based on a model representing an expected electromagnetic signal digital representation;

detecting a first remaining portion of the electromagnetic signals that align in phase with a waveform of radar signals transmitted by the radar unit and a second remaining portion of the electromagnetic signals that differ in phase from the waveform of the radar signals;

applying one or more filters to the second remaining portion of the electromagnetic signals to isolate and differentiate measurements from the second remaining portion of the electromagnetic signals relative to measurements from the first remaining portion of the electromagnetic signals; and

generating, by the computing device and using the first and the second remaining portions of the electromagnetic signals, a representation of the environment that indicates positions of a plurality of surfaces relative to the vehicle.

2. The method of claim 1 ,

wherein generating the representation of the environment comprises:

generating at least a first portion of the representation of the environment using the first remaining portion of the electromagnetic signals that align in phase with the waveform of radar signals transmitted by the radar unit.

3. The method of claim 2 ,

wherein generating the representation of the environment further comprises:

generating at least a second portion of the representation of the environment using the second portion of the electromagnetic signals based on isolating and differentiating measurements from the second portion of the electromagnetic signals relative to measurements from the first portion of the electromagnetic signals.

4. The method of claim 1 , wherein applying the one or more filters to the second remaining portion of the electromagnetic signals comprises:

applying one or more range and Doppler filters to the second remaining portion of the electromagnetic signals.

5. The method of claim 1 , wherein generating the representation of the environment comprises:

generating a set of representations of the environment using electromagnetic signals received at a plurality of radar units; and

aligning the set of representations of the environment to produce a total representation that represents the environment extending 360 degrees around the vehicle.

6. The method of claim 1 , wherein receiving electromagnetic signals propagating in the environment of the vehicle via the radar unit coupled to the vehicle comprises:

receiving the electromagnetic signals using a reception antenna array configured to receive electromagnetic signals propagating in a particular polarization.

7. The method of claim 1 , wherein removing second portions of the electromagnetic signals comprises:

performing a comparison between a digital representation of the electromagnetic signals and the expected electromagnetic signal digital representation;

identifying one or more spikes and plateaus associated with signal interference based on the comparison; and

removing given portions of the electromagnetic signals corresponding to the one or more spikes and plateaus associated with signal interference; and

repairing the digital representation of the electromagnetic signals based on the expected electromagnetic signal digital representation.

8. The method of claim 7 , wherein generating the representation of the environment comprises:

generating the representation of the environment using the repaired digital representation of the electromagnetic signals.

9. The method of claim 1 , further comprising:

determining, using the electromagnetic signals, one or more electromagnetic signals that originated from an external emitter;

estimating a direction of arrival for the one or more electromagnetic signals; and

based on the direction of arrival, estimating a location for the external emitter relative to the vehicle using a frequency-difference of arrival (FDOA) process or a time-difference of arrival (TDOA).

10. The method of claim 9 , further comprising:

generating a signature for the external emitter, wherein the signature indicates the location for the external emitter and one or more parameters for the one or more electromagnetic signals that originated from the external emitter.

11. The method of claim 10 , further comprising:

estimating a time period and a frequency bandwidth for the one or more electromagnetic signals; and

assigning the time period and the frequency bandwidth to the signature for the external emitter.

12. The method of claim 11 , further comprising:

providing the signature for the external emitter to one or more external computing devices.

13. The method of claim 12 , wherein providing the signature for the external emitter to one or more external computing devices comprises:

providing the signature for the external emitter to one or more vehicles located within a threshold distance from the vehicle.

14. The method of claim 1 , further comprising:

controlling the vehicle based on the representation of the environment.

15. A system comprising:

a radar unit coupled to a vehicle; and

a computing device configured to:

receive electromagnetic signals propagating in an environment via the radar unit, wherein a field of view of the radar unit limits the electromagnetic signals received to a particular angle of arrival and a polarization of one or more reception antennas of the radar unit limits the electromagnetic signals received to a particular polarization;

apply a set of filters to the electromagnetic signals to remove first portions of the electromagnetic signals that are outside an expected time range and an expected frequency range, wherein the expected time range and the expected frequency range depend on radar signal transmission parameters used by the radar unit; and

remove second portions of the electromagnetic signals that are indicative of spikes and plateaus associated with signal interference based on a model representing an expected electromagnetic signal digital representation;

detect a first remaining portion of the electromagnetic signals that align in phase with a waveform of radar signals transmitted by the radar unit and a second remaining portion of the electromagnetic signals that differ in phase with the waveform of the radar signals;

apply a plurality of filters to the second remaining portion of the electromagnetic signals to isolate and differentiate measurements from the second remaining portion of the electromagnetic signals relative to measurements from the first remaining portion of the electromagnetic signals; and

generate, using the first and the second remaining portions of the electromagnetic signals, a representation of the environment that indicates positions of a plurality of surfaces relative to the vehicle.

16. The system of claim 15 , wherein the computing device is further configured to:

control the vehicle based on the representation of the environment.

17. The system of claim 15 , wherein the computing device is further configured to:

cause the radar unit to transmit radar signals into the environment according to a set of parameters, wherein the set of parameters include a time range from the expected time range and a particular frequency from the expected frequency range; and

receive the electromagnetic signals in response to causing the radar unit to transmit radar signals into the environment according to the set of parameters.

18. The system of claim 15 , wherein the computing device is further configured to:

generate at least a first portion of the representation of the environment using the first remaining portion of the electromagnetic signals that align in phase with the waveform of radar signals transmitted by the radar unit.

19. The system of claim 18 , wherein the computing device is further configured to:

generate at least a second portion of the representation of the environment using the second remaining portion of the electromagnetic signals based on isolating and differentiating measurements from the second remaining portion of the electromagnetic signals relative to measurements from the first remaining portion of the electromagnetic signals.

20. A non-transitory computer-readable medium configured to store instructions, that when executed by a computing system comprising one or more processors, causes the computing system to perform operations comprising:

receiving electromagnetic signals propagating in an environment via a radar unit coupled to a vehicle, wherein a field of view of the radar unit limits the electromagnetic signals received to a particular angle of arrival and a polarization of one or more reception antennas of the radar unit limits the electromagnetic signals received to a particular polarization;

applying a set of filters to the electromagnetic signals to remove first portions of the electromagnetic signals that are outside an expected time range and an expected frequency range, wherein the expected time range and the expected frequency range depend on radar signal transmission parameters used by the radar unit; and

removing, using a model, second portions of the electromagnetic signals that are indicative of spikes and plateaus associated with signal interference based on a model representing an expected electromagnetic signal digital representation;

detecting a first remaining portion of the electromagnetic signals that align in phase with a waveform of radar signals transmitted by the radar unit and a second remaining portion of the electromagnetic signals that differ in phase from the waveform of the radar signals;

applying one or more filters to the second remaining portion of the electromagnetic signals to isolate and differentiate measurements from the second remaining portion of the electromagnetic signals relative to measurements from the first remaining portion of the electromagnetic signals; and

generating, using the first and the second remaining portions of the electromagnetic signals, a representation of the environment that indicates positions of a plurality of surfaces relative to the vehicle.