Doppler Ambiguity Resolution for a PMCW Automotive Radar System

This paper presents a novel method for the identification and resolution of targets with ambiguous velocities within a single measurement cycle of a phase-modulated continuous wave (PMCW) radar system based on multi-hypothesis Doppler shift compensation. The Doppler shift is first compensated by assuming that the velocities of all targets are unambiguous. Since targets with velocity ambiguity cannot be perfectly compensated in their range profiles based on this assumption, ambiguities can be identified after the range correlation processing. The range correlation processing for ambiguous targets is then repeated under multiple velocity hypotheses. The velocity hypothesis with the best sidelobe suppression is considered the correct velocity. As a result, the Doppler shift compensation in the range profile is achieved as well. Simulation results show that the proposed method can simultaneously resolve velocity ambiguities and compensate for the Doppler shift induced increased sidelobe level in the range profile.