ReMCW: Reduced Bandwidth FMCW Radar for Autonomous Driving

Automotive radar is an all-weather sensing technology that makes direct measurements of target motion thereby aiding in unmanned driving. Continuous-wave (CW) radars which use linear frequency modulation (FM) have been the most popular automotive sensing systems because of lower cost, higher range resolution, and lower transmit power than a pulse Doppler radar. The available spectrum for vehicular systems is limited and, therefore, avoiding mutual interference from multiple automotive radars operating in the same spectrum in a crowded traffic scenario is a major challenge. To address this, we present a Reduced bandwidth FMCW (ReMCW) radar that consumes less spectral resources without decreasing the range resolution and enables interference-free operation. Our CW radar waveform transmits few randomly chosen slopes within the original FMCW sweep. This waveform avoids range- Doppler coupling encountered in conventional FMCW radars. The parameters used for the design of this waveform conform to current automotive radar requirements. Numerical experiments with ReMCW show great savings in spectrum over the conventional FMCW radar.