Waveform covariance matrix design for robust signal-dependent interference suppression in colocated MIMO radars

In multiple-input multiple-output (MIMO) radars, interference can be properly suppressed by designing transmit waveforms. However, having an error in initial estimation of interferers' locations can result in degradation of signal-to-interference-plus-noise ratio (SINR), significantly. In this paper we consider the problem of robust interference suppression and SINR increment in collocated MIMO radars, in the presence of signal-dependent interference resources. We propose an efficient method to generate transmit waveform covariance matrix with the following properties: (a) robustness in interference suppression, (b) high SINR at the receiver, c) using the same power level for all transmit antennas and (d) suitable for generating BPSK waveforms in a closed-form. We solve the resulted optimization problems with numerical approaches in a short period of time. The proposed covariance matrix, by exploiting the correlated MIMO radar concept and a technique we use in the transmitter, yields to a better SINR level compared to conventional MIMO radars, phased array method and the recent introduced schemes. Simulation results validate our claims and show the advantages of our work. (C) 2018 Elsevier B.V. All rights reserved.