Energy-Efficiency Resource Allocation for D2D Communications Under-Laying UAV Networks

Device-to-Device (D2D) communications under-laying Unmanned aerial vehicle (UAV) with its mobility extend the coverage and improve system capacity and flexible networking capabilities. However, the energy-efficiency are major challenge in UAV-assisted D2D networks. In this paper, the joint power and channel optimization problem has been investigated to maximize the system energy efficiency. Using the properties of objective function, the original optimization problem is transformed into two sub-problems. In the first step, the optimal power allocation problem is solved by using the Nash balance point of non-cooperative Game theory. In the second step, the channel allocation problem is constructed into a Bipartite graph, and then the Hungarian algorithm is used to find the best matching. The numerical simulation results show that the proposed scheme not only improves the energy efficiency of the system but also enhances the spectral efficiency.