Doppler processing in frequency-modulated continuous wave radar systems using dither

A method comprising:

• generating, by a radar sensor, range-gate data representing the position of an object within a region of interest;
• performing a first Doppler Fast Fourier Transform (Doppler-FFT) on the range-gate data to provide a first set of Doppler-FFT data, the first set of Doppler-FFT data;
• identifying a first velocity associated with a first signal amplitude that exceeds a first noise floor with respect to the first set of Doppler-FFT data;
• determining a first correction value for the range-gate data from the identified first velocity;
• modifying the range-gate data using the determined first correction value to provide a first set of modified range-gate data;
• performing a second Doppler-FFT on the first set of modified range-gate data to provide a second set of Doppler-FFT data;
• identifying a second velocity associated with a second signal amplitude that exceeds second noise floor with respect to the second set of Doppler-FFT data;
• determining a second correction value for the first set of modified range-gate data from the identified second velocity;
• modifying the first set of modified range-gate data using the determined second correction value to provide a second set of modified range-gate data;
• and
• applying a third Doppler-FFT to the second set of modified range-gate data to provide a third set of Doppler-FFT data.

A system comprising:

• a radar sensor module configured to generate range-gate data representing the position of an object within a region of interest;
• and
• a signal processor configured to perform a Doppler Fast Fourier Transform (Doppler-FFT) on the range-gate data to provide Doppler-FFT data identify a velocity associated with a signal amplitude in the Doppler-FFT that exceeds a noise floor with respect to the Doppler-FFT data, determine a set of correction values, each associated with a return signal of a chirp in a frame of chirps, as
• e
• 4
• ⁢
• π
• ⁢
• ⁢
• jv
• 1
• ⁢
• Δ
• n
• λ
• ,
• where v1 is the velocity associated with the signal amplitude that exceeds the noise floor, Δn is the dither in the timing between the n−1th and the nth chirp in the frame, and λ is a wavelength associated with a carrier frequency of the transmitted chirp, and modify the range-gate data by applying phase rotations to the range-gate data based on the determined set of correction values to provide modified range-gate data.