Energy-Efficient Power Allocation for Multi-user D2D Underlay Communications in Distributed Antenna System

In this paper, the energy-efficient power allocation (PA) for multi-user Device-to-Device (D2D) underlay communications in distribu-ted antenna system is presented. The optimization problem of maximizing the energy efficiency (EE) of all D2D links is formulated with the minimum rate requirements and maximum transmit power constraints. To solve the non-linear and non-convex optimization problem with low complexity, the original problem is decomposed into two subproblems using the block coordinate descent algorithm. The non-convex subproblems are solved by the concave-convex procedure and successive convex approximation methods. Simulation results show that the EE performance improvement is achieved by the proposed PA scheme compared with the benchmark algorithm.