A Doppler De-aliasing Technique for FMCW-TDM MIMO Automotive Radar

The problem of diminished unambiguous target velocity interval induced by the time-division-multiplex mode (TDM) of multi-input-multi-output (MIMO) frequency-modulated continuous wave (FMCW) automotive radar has been explored. A novel MIMO antenna array activation mode and a parametric approach for Doppler de-aliasing based on a two-step cross-entropy optimization are proposed. The TDM Doppler signal model has been derived, and a novel two-step cost function is proposed to achieve robust and efficient estimation. In contrary to the state-of-the-art method, the method proposed does not need multiple overlapped antennas and can resolve multiple targets in the same range and Doppler bins. The proposed method has been verified with numerical simulations with different parameter settings, as well as experimental data from a radar target simulator.