Waveform Design for MIMO Radar Based on Mutual Information and Minimum Mean-Square Error Estimation

This paper addresses the problem of optimum radar waveform design for both radars employing a single transmit and receive antenna and the recently proposed multiple-input multiple-output (MIMO) radar. A random target impulse response is used to model the scattering characteristics of the target, and both point and extended radar targets are considered. Assuming the constraint on waveform power, two radar waveform design problems have been investigated. The first one is to design waveforms that maximize the conditional mutual information (MI) between the random target impulse response and the reflected waveforms given the knowledge of the transmitted waveforms. The second one is to find transmitted waveforms that minimize the minimum mean-square error (MMSE) in estimating the target impulse response. Our analysis indicates that under the same total power constraint, these two criteria lead to the same solution for a matrix which specifies the essential part of the optimum waveform design. The solution employs water-filling to allocate the limited power appropriately. We also present an asymptotic formulation which requires less knowledge of the statistical model of the target.