Unitary reduced-dimensional estimation of signal parameters via rotational invariance techniques for angle estimation in monostatic multiple-input–multiple-output radar with rectangular arrays

In this study, the issue of two-dimensional direction of arrival estimation in monostatic multiple-input-multiple-output (MIMO) radar with rectangular arrays is studied and an algorithm based on estimation of signal parameters via rotational invariance techniques (ESPRIT) is proposed. Through the reduced-dimensional transformation and unitary transformation, the proposed algorithm has very low complexity because of the low-dimension and real-valued computations. Meanwhile, the angle estimation performance of the proposed algorithm is improved compared with conventional ESPRIT and Unitary ESPRIT. The real-valued rotational invariance is utilised to achieve automatically paired estimations of the azimuth and elevation angles in monostatic MIMO radar. Error analysis of the angle estimation and Cramér-Rao bound in MIMO radar are derived. Simulation results verify the improvement and usefulness of our algorithm.