Interleaving radar range and doppler processing

A non-transitory computer-readable storage media comprising instructions that, when executed, cause a processor of a radar system to:

• maintain, in a memory of the radar system,
• a data cube of sufficient size to store processed radar data for a single look period;
• perform, during a first look period, the following steps:
• receive a first plurality of samples of radar returns corresponding to a first plurality of chirps transmitted across multiple channels into an environment outside a vehicle;
• perform range processing by determining a first range result for each sample of the first plurality of samples of radar returns by performing a Fast Fourier Transform (FFT) on each sample;
• write the first plurality of range results for each sample of the first plurality of samples of radar returns to the data cube, wherein the processor writes each range result to the data cube horizontally;
• and
• perform Doppler processing by reading, in response to completing the writing step for each sample of the first plurality of samples of radar returns, a portion of the first plurality of range results written to the data cube comprising less than half of the data cube, wherein a Doppler processor reads the first plurality of range results in the data cube vertically and empties the range results from the data cube after they are read;
• perform during a second look period following the first look period, the following steps:
• determine that a predetermined threshold percentage of the data cube has been emptied;
• receive a second plurality of samples of radar returns corresponding to a second plurality of chirps transmitted across multiple channels into an environment outside the vehicle, wherein the reception of each sample of the second plurality is followed by a waiting period during which samples are not received;
• perform range processing by determining, in response to determining that the predetermined threshold percentage has been reached, a second range result for each sample of the second plurality of samples of radar returns by performing FFT on each sample;
• write, beginning with the empty portion of the data cube, the second plurality of range results for each sample of the second plurality of samples of radar returns to the data cube, wherein the processor writes each range result to the data cube vertically;
• and
• read, during the waiting period between samples, the remaining portion of the first plurality of range results written to the data cube, wherein the Doppler processor continues to read the remainder of the first plurality of range results in the data cube vertically and empties the range results from the data cube after they are read;
• and output an indication of the data cube for use by a function of the vehicle.

A method for radar signal processing in a vehicle, comprising:

• maintaining, in a memory of a radar system, a data cube of sufficient size to store processed radar data obtained for a single look period;
• performing, by the radar system and during a first look period, the following steps:
• receiving, by the radar system, a first plurality of samples of radar returns corresponding to a first plurality of chirps transmitted across multiple channels into an environment outside the vehicle;
• determining, by a range estimator of the radar system, a first range result for each sample of the first plurality of samples of radar returns by performing a Fast Fourier Transform (FFT) on each sample;
• writing, by the range estimator, the first plurality of range results for each sample of the first plurality of samples of radar returns to the data cube, wherein the range estimator writes each range result to the data cube horizontally;
• and
• reading, by a doppler estimator of the radar system and in response to the range estimator completing the writing step for each sample of the first plurality of samples of radar returns, a portion of the first plurality of range results written to the data cube by the range estimator comprising less than half of the data cube, wherein the doppler estimator reads the first plurality of range results in the data cube vertically and empties the range results from the data cube after they are read;
• performing, by the radar system and during a second look period following the first look period, the following steps:
• determining, by the radar system, that the doppler estimator has emptied a predetermined threshold percentage of the data cube;
• receiving, by the radar system, a second plurality of samples of radar returns corresponding to a second plurality of chirps transmitted across multiple channels into an environment outside the vehicle, wherein the reception of each sample of the second plurality is followed by a waiting period during which the radar system does not receive samples;
• determining, by the range estimator of the radar system and in response to determining that the predetermined threshold percentage has been reached, a second range result for each sample of the second plurality of samples of radar returns by performing FFT on each sample;
• writing, by the range estimator and beginning with the empty portion of the data cube, the second plurality of range results for each sample of the second plurality of samples of radar returns to the data cube, wherein the range estimator writes each range result to the data cube vertically;
• and
• reading, by the doppler estimator and during the waiting period between samples when the radar system is not receiving samples, the remaining portion of the first plurality of range results written to the data cube by the range estimator, wherein the doppler estimator continues to read the remainder of the first plurality of range results in the data cube vertically and empties the range results from the data cube after they are read;
• and
• outputting, from the radar system, an indication of the data cube for use by a function of the vehicle.