MIMO radar detection and adaptive design under a phase synchronization mismatch

We consider the problem of target detection for multi-input multi-output radar with widely separated antennas in the presence of a phase synchronization mismatch between the transmitter and receiver pairs. Such mismatch often occurs due to imperfect knowledge of the locations and local oscillator characteristics of the antennas. First, we introduce a data model using a von Mises distribution to represent the phase error terms. Then, we employ an expectation-maximization algorithm to estimate the error distribution parameter, target returns, and noise variance. We develop a generalized likelihood ratio test target detector using these estimates. Based on the mutual information between the radar measurements and received target returns (and hence the phase error), we propose an algorithm to adaptively distribute the total transmitted energy among the transmitters. Using Monte Carlo simulations, we demonstrate that the adaptive energy allocation, increase in the phase information, and realistic measurement modeling improve the detection performance.