FMCW radar signal processing for distance estimation

A method for calibrating a Frequency-Modulated Continuous-Wave (FMCW) radar sensor, the FMCW radar sensor comprising a transmitter, a receiver and a signal processor, the method comprises acquiring a plurality of waveform metrics corresponding to a plurality of known distances to a target, wherein the method comprises, for each distance among the plurality of known distances:

• emitting, by the transmitter, a radio wave, wherein the radio wave frequency is modulated over time;
• obtaining, by the receiver, during said emitting of the radio wave, a time-domain in-phase signal and/or a time-domain quadrature-phase signal indicative of amplitude and phase information of an echo of the emitted radio wave;
• selecting for processing, by the signal processor, the time-domain in-phase signal and/or the time-domain quadrature-phase signal;
• isolating, by the signal processor, a segment of the selected time-domain in-phase signal and/or the time-domain quadrature-phase signal;
• extracting, by the signal processor, a waveform metric from the isolated segment of the selected time-domain in-phase signal and/or the time-domain quadrature-phase signal;
• wherein the method further comprises:
• determining, by the signal processer, a predetermined function by correlating the plurality of acquired waveform metrics with the corresponding plurality of known distances.

A Frequency-Modulated Continuous-Wave FMCW radar sensor, the sensor comprising:

• a transmitter configured to emit a radio wave, wherein the radio wave frequency is modulated over time;
• a receiver configured to obtain, while the transmitter emits the radio wave, a time-domain in-phase signal and/or the time-domain quadrature-phase signal that is indicative of the amplitude and phase information of an echo of the emitted radio wave;
• and,
• a signal processor operatively connected to the receiver, the signal processor being configured to:
• select for processing the time-domain in-phase signal and/or the time-domain quadrature-phase signal;
• isolate a segment within the selected time-domain in-phase signal and/or the time-domain quadrature-phase signal;
• extract a waveform metric from the isolated segment of the selected time-domain in-phase signal and/or the time-domain quadrature-phase signal;
• and
• obtaining, by the signal processor, a predetermined function defining a mapping between a plurality of waveform metrics and a corresponding plurality of distance values;
• obtaining, by the signal processor, a predetermined function defining a mapping between a plurality of waveform metrics and a corresponding plurality of distance values;
• inputting, by the signal processer, the extracted waveform metric to the predetermined function;
• receiving, by the signal processor, a distance outputted by the predetermined function.