Joint Antenna Selection and Beamforming for Multitarget Tracking With Interference Suppression in Colocated MIMO Radar

This paper addresses the joint optimization problem of antenna selection and transmit-receive beamforming design in a colocated multiple-input multiple-output (C-MIMO) radar system used for multi-target tracking (MTT) in the presence of directional interferers. We first derive the mathematical relationships between the predictive posterior Cramér-Rao lower bound (PCRLB) and key C-MIMO radar parameters, including antenna selection vector, transmit signal correlation matrix, and receive beamforming weights. To achieve the best utilization of antenna resources, we then seek to minimize the number of selected antennas employed for MTT while nulling interference and achieving a desired spatial response and target tracking accuracy. Since the formulated optimization problem is an untractable non-convex mixed-integer nonlinear program, we propose a joint antenna selection and beamforming algorithm based on block coordinate descent (BCD) to solve it effectively. Specifically, the optimization problem is decomposed into three iterated subproblems for solving the receive beamforming weights, the transmit signal correlation matrix, and the antenna selection vector. Each subproblem is addressed using either convex optimization techniques or iterative approximate convex methods. Simulation results demonstrate that the proposed algorithm can achieve excellent performance in minimizing antenna resources while reliably satisfying the given beamforming constraints and MTT accuracy requirements.