Receive-beam allocation for multiple target tracking with distributed MIMO radar systems

A distributed multiple-input multiple-output (MIMO) radar system is capable of tracking multiple targets under the "defocused transmit-focused receive" (DTFR) operating mode in which each transmitter forms a completely defocused beam to illuminate the whole surveillance region and each receiver adopts a focused beam to attain a higher resolution. However, when operating in this mode, there exists a resource optimization problem on the allocation of receive-beams. To address this problem, a receive-beam resource allocation (RBRA) strategy is proposed in this paper. The key mechanism is to implement the optimal allocation between receive-beams and targets based on the feedback information in the tracking recursion cycle, for the purpose of improving the worst tracking accuracy with multiple targets. Since the posterior Cramér-Rao lower bound (PCRLB) provides a tight lower bound on the accuracy of target state estimates, it is derived and adopted as an optimization criterion. It is shown that the optimal RBRA is a multidimensional non-convex assignment problem and we propose an effective convex relaxation optimization to solve it. Numerical results demonstrate the superior performance of the proposed strategy.