LPI-based optimal power allocation scheme for multiple targets tracking in collocated MIMO radar

In this paper, a low probability of intercept (LPI)-based optimal power allocation (PA) scheme is developed for multiple targets tracking (MTT) in collocated multiple-input-multiple-output (C-MIMO) radar system. The core of the LPI-PA scheme is to adaptively manage the transmit power to improve the LPI performance of the radar, subject to the system resource budget and quality of service (QoS) requirements constraint. The predicted Bayesian Cramér-Rao lower bound (BCRLB) and the overall probability of the radar system being intercepted by enemy targets are derived and employed as the metrics to quantify the target tracking accuracy and LPI performance, respectively. It is shown that the LPI-PA scheme is formulated as a nonlinear and non-convex optimization problem. By assessing whether all targets can meet the predefined QoS requirements, the original problem can be transformed into the following two problems: accelerating the decrease of MTT error under a given total interception probability threshold constraint (when the original problem is infeasible), and minimizing the total interception probability under the QoS threshold constraint (when the original problem is feasible). We fully verify that the total interception probability constraint forms a convex set and subsequently propose two effective methods to address these problems by exploring their unique structures. Simulation results demonstrate the effectiveness of the proposed LPI-PA scheme.