Self-interference cancellation for frequency-modulated continuous-wave radar

A method for mutual coupling cancellation, comprising:

• sampling, by a circuit, a transmit chirp;
• modulating, by the circuit, the transmit chirp with a continuous-wave (CW) tone having a frequency based on a mutual coupling delay associated with the transmit chirp;
• estimating, by the circuit, a receive chirp based on the modulated transmit chirp and one or more estimated parameters associated with a mutual coupling channel;
• and
• cancelling, by the circuit, a mutual coupling signal from the receive chirp based on the estimated receive chirp.

A method for adaptive delay compensation, comprising:

• obtaining, by a circuit, a beat signal by multiplying a transmitted reference chirp with an interfering signal caused by mutual coupling from a transmitter to a receiver;
• applying, by the circuit, a discrete Fourier transform (DFT) to the beat signal to generate a spectrum representing the beat signal in a frequency domain;
• generating, by the circuit, a continuous-wave (CW) tone having a frequency associated with a maximum peak in the spectrum representing the beat signal;
• and
• providing, by the circuit, the CW tone to a cancellation filter configured to cancel a mutual coupling signal from a receive chirp based on a sampled transmit chirp, the CW tone, and one or more parameters associated with the mutual coupling.