MIMO-Sparse Radars for Enhanced DOA Estimation of Spatio-Temporal Correlated Sources

This paper investigates an enhanced direction-of-arrival (DOA) estimation problem of spatio-temporal correlated sources when a multiple-input multiple-output (MIMO) sparse radar is deployed. A virtual array with increased degrees-of-freedom (DOF) is realized within two steps by combining MIMO radar with the Khatri-Rao (KR) product approach. Since the final virtual array is a uniform linear array (ULA), a well-known spatial smoothing algorithm is applied to reinforce the rank of its covariance matrix. Meanwhile, the enhanced DOF results in a higher spatial resolution of the radar in the context of DOA estimation.