Energy Efficient D2D Communications Using Multiple UAV Relays

In this paper, we propose a novel optimization model for multiple Unmanned Aerial Vehicles (UAVs) working simultaneously as relays to help two set of ground users; namely relay users and device-to-device (D2D) users. The are assumed out communication rages from each other use the UAV link their data transmission. While D2D be nearby managing resources without being involved in goal paper is operate UAVs an energy-efficient manner support different by i) optimizing available bandwidth power allocations links, ii) acting when needed maintain links between We formulate problem that maximizes throughput-energy utility while respecting resource availability including UAVs’ energy consumption, UAV-user association, trajectory constraints. Due non-convexity problem, solve it three steps using Taylor series approximation. Firstly, optimize transmit Then, allocation given values. Finally, efficient heuristic algorithm based on recursive shrink-and-realign process proposed trajectories. performance method shows advantages terms average throughput compared fixed solutions.