New Approach for DOA Estimation in MIMO Radar With Nonorthogonal Waveforms

It is desirable to emit orthogonal waveforms in multiple-input multiple-output (MIMO) radar systems. Unfortunately, the waveform orthogonality may not be always guaranteed in practice. Nonorthogonal transmit waveforms will incur two challenges i.e., spatially colored noise and nonideal virtual direction matrix, for direction-of-arrival (DOA) estimation in colocated MIMO radar. In this article, a temporal cross-correlation matrix-based algorithm is proposed to overcome the above drawbacks. Also, the stochastic Cramér-Rao bound (CRB) is derived. The proposed algorithm does not require the prior knowledge of the waveform correlation matrix. Moreover, it is attractive from the perspective of efficiency as well as accuracy. Numerical experiments demonstrate the effectiveness of our algorithm.