Optimal Antenna Selection Sequence for MIMO Radar

Operation of the multiple-input multiple-output (MIMO) radar requires orthogonality between signals transmitted from multiple transmitters. A simple way to obtain this orthogonality is by time division multiplexing, where at each time slot the signal is transmitted from one antenna. However, this sequential antenna selection approach introduces a coupling between direction-of-arrival (DOA) and Doppler in the ambiguity function. The sidelobe levels in the ambiguity function depend on the antenna selection sequence. These sidelobe levels increase the threshold signal-to-noise ratio (SNR) for DOA and Doppler estimation. In this paper, we derive the Weiss-Weinstein bound (WWB) for DOA and Doppler estimation in MIMO radar and minimize it for determining the antenna selection sequence. It is shown via simulations that the proposed method outperforms random and linear antenna selection sequences in DOA and Doppler estimation.