Joint User Scheduling, Power Allocation, and Trajectory Design for Joint Synthetic Aperture Radar and Communication UAV Systems

Due to the highly controllable mobility, unmanned aerial vehicles (UAVs) are able to simultaneously provide efficient communication and synthetic aperture radar (SAR) based high-precision sensing. In this paper, we investigate joint user scheduling, power allocation, and trajectory design in a joint SAR and communication (JSARC) UAV system. Two problems, i.e. maximization of minimum user throughput and maximization of sum throughput, are investigated under transmit power, UAV mobility, and SAR-based sensing constraints. We propose two joint user scheduling, power allocation and trajectory design (JUPT) algorithms for solving the non-convex problems via alternating optimization. In particular, to execute power allocation more efficiently, two bi-section searching methods are proposed based on Karush-Kuhn-Tucker (KKT) conditions. Simulation results validate the efficiency of the proposed algorithms by illustrating the convergence behavior. The impacts of various factors on sum/minimum user throughput have been investigated, and distinct user scheduling and power allocation results for the two cases are provided.