Doppler Robustness Analysis of Orthogonal Sequences for MIMO PMCW Radar

Phase modulated continuous wave (PMCW) radars are gaining attention as an alternative to currently used radar systems such as chirp sequence and orthogonal frequency-division multiplexing (OFDM) in a variety of applications. The use of orthogonal sequences enables multiple-input multiple-output (MIMO) operation, but the achieved orthogonality, measured as separability, suffers from degradation in the presence of moving targets. Orthogonal sequences for MIMO PMCW radars are investigated in terms of the achieved separability and the degradation experienced due to non-zero Doppler shifts. More precisely, m-sequences, Gold sequences, Kasami sequences, ZCZ sequences, and Golay sequences are presented and a correlation performance aware sequence choice is introduced.