Energy-Efficient Symbiotic Cellular-UAV Communication via aerial RIS: Joint Trajectory Design and Resource Optimization.

Reconfigurable intelligent surface (RIS) enables the wireless propagation environment to be reconstructed intelligently. In this paper, we consider a symbiotic cellular-UAV communication network in which the base station communicates with both its cellular users and an UAV equipped with an aerial RIS. Our objective is to maximize the energy efficiency of this network by jointly optimizing the UAV trajectory, user access indicator factor, the base station's active beamforming and the RIS's passive beamforming. Simulation results show that the proposed dynamic time-division-multiple-access communication scheme can significantly improve the network's energy efficiency compared with the communication-and-hover benchmark.