UAV Trajectory Design and Power Allocation for Device-Clustering Covert Communications

We consider an uncrewed aerial vehicle (UAV) covert communication network, where a UAV covertly transmits information to clustered ground devices (GDs) under the warden detection. A joint continuous UAV trajectory and power allocation problem is formulated to maximize the minimum throughput among GDs subject to the covertness and the UAV mobility constraints. Considering the device clustering characteristics and the optimal successive-hover-and-fly (SHF) structure, we propose a two-stage SHF algorithm. Specifically, the UAV's SHF trajectory and cluster-level power allocation are first optimized to maximize the minimum throughput among clusters, and then intra-cluster power coefficients are optimized to maximize the minimum throughput among intra-cluster GDs. Compared with the benchmark SHF algorithm, the proposed algorithm significantly reduces the computation complexity while keeping nearly unchanged performance.