Doppler-Range Processing for Enhanced High-Speed Moving Target Detection using LFMCW Automotive Radar

The two well-known problems of high-speed moving target detection in linear frequency-modulated continuous wave (LFMCW) automotive radar applications are range/Doppler migration and velocity ambiguity. We introduce a simple Doppler-Range Processing (DRP) algorithm to mitigate the problems by first performing Doppler processing via fast Fourier transform (FFT) across slow-time chirps, followed by range processing via FFT along Doppler migration lines over fast-time samples. The proposed DRP algorithm can achieve the same range and velocity resolutions, as well as full coherent integration gains, as the conventional Range-Doppler processing (RDP) method in the static trivial case, with comparable computational complexities. We prove that the proposed DRP method can automatically resolve the velocity ambiguity and we also analyze its velocity ambiguity resolving capability in relation to the radar bandwidth and the number of chirps with a CPI. We further present a data-adaptive spotlighting (DAS) algorithm for detecting weak targets shadowed by strong targets or clutter. The effectiveness of the proposed algorithms are demonstrated by numerical examples.

• Algorithms and Theory