Energy Consumption Optimization for UAV-Assisted Communication by Trajectory Design

Unmanned aerial vehicles (UAVs) could be dispatched to areas of interest and act as intermediate relays to transmit information from areas of interest to the ground data center due to their flexible mobility. The UAV-assisted communication network consists of the aerial subnetwork and the ground subnetwork. The aerial subnetwork is forming by UAVs, which aids the ground subnetwork through air-to-air (A2A) and air-to-ground (A2G) communications link. To collect information with the minimum energy consumption of UAVs, in this paper, we jointly optimize the trajectory, the number and locations of UAVs while considering the coverage of the area. The optimization problem is a mixed integer non-convex problem, we decompose it into two sub-problems and solved separately. Firstly, the UAVs deployment (UD) algorithm is used to determine the number and locations of UAVs with the consideration of the coverage. Secondly, the improved shuffled frog-leaping algorithm (ISFLA) based on the Dubins path is proposed to optimize the trajectory of UAVs with obstacle avoidance. Finally, simulation results demonstrate that the proposed algorithm could achieve superior performance compared with algorithms in the literatures.