Sum-Rate Maximization for D2D-Enabled UAV Networks With Seamless Coverage Constraint

This article investigates sum-rate maximization while achieving seamless coverage with the minimum number of unmanned aerial vehicles (UAVs) in a device-to-device (D2D)-enabled UAV network. Toward this end, we formulate it as a nonlinear and nonconvex optimization problem, and then propose a max-rate-min-number (MRMN) scheme to solve this optimization problem. First, we derive UAV’s coverage radius which can depict the maximum coverage for user equipments, and then implement the optimal deployment for UAV swarm by exploiting the disk covering theory. Furthermore, we apply the coalitional game theory to design the cooperative strategy between UAV swarm and ground equipments. Finally, a coalition formation algorithm is presented for achieving maximum system sum-rate while reducing the number of UAVs under seamless coverage constraint. Extensive simulation results are provided to validate the effectiveness of our proposed MRMN scheme, and also illustrate that the scheme can improve the system sum-rate and reduce the number of deployed UAVs. Meanwhile, we further conduct a performance comparison between our scheme and the existing benchmark schemes.