Doppler Shifts Mitigation for PMCW Signals

The Doppler shift mitigation for phase-modulated continuous wave (PMCW) of multiple moving targets is studied. As for joint range and Doppler information extraction, the transmitted PMCW signals are split into the slow-time domain and fast-time domain. The Doppler information is usually directly estimated from the Fourier analysis of the slow-time domain. However, such Doppler frequency shift remains in the fast-time domain after mixing with the carrier wave and degrades the orthogonality of the codes, which results in the peak energy loss and high-level side-lobes. This paper analyses the problem mathematically and proposes a novel method for Doppler shift mitigation. The performance of the proposed method is validated by numerical simulations.