An efficient radar-target assignment and power allocation strategy for low-angle tracking in the MIMO-multisite radar system

How to utilize limited resources effectively in a multiple-input multiple-output (MIMO) radar network plays a critical role in its tracking capability. In this paper, a joint radar target assignment and power allocation (JRTAPA) strategy is proposed for the MIMO-multisite radar system (MIMO-MSRS) tracking low-angle targets. The MIMO-MSRS integrates the distributed MIMO radar architecture and the digital beamforming (DBF) technique, and hence better tracking performance in low-angle tracking is achievable. The mechanism of JRTAPA strategy is to allocate the limited beam and power resources using the prior target information feedback from the tracking recursive cycle. The location posterior Cramér-Rao lower bound (PCRLB) under the multipath interference (MI) is derived and adopted as the constraint metric. Considering the specific tracking accuracy requirement of each target, a quality of service (QoS)-based optimization model is established to minimize the total power consumption. An efficient two-stage Karush–Kuhn–Tucker (KKT) condition-based solver is proposed for solving such a nonconvex optimization model. The simulation results confirm the superiority of the proposed JRTAPA strategy over the joint scheduling and power allocation (JSPA) strategy, the target assignment and resource optimization (JTARO) strategy, as well as the exhaustive search-based algorithm. The results also reveal that the target geometry and tracking accuracy requirements have important effects on resource allocation.