Resources Allocation based on Fair Energy Efficiency in Wireless Powered Communications Network

 In this paper, we will try to examine the energy efficiency by allocating resources in wireless powered communications networks (WPCNs). In this study, the several users initially receive energy from the power station and then communicate with the information station. This paper deals with the fairness on the user's energy efficiency while ensuring minimum throughput for users and fulfilling the energy harvesting power constraints. The problem variables are the timing between receiving energy and sending information per user, and the transmit power of each user, whereas in the previous works, it has not been considered as joint allocation. Due to the non-convex nature of the problem, the some simplifications are used for solving it . In order to solve simplified problem, we present an innovative iterative algorithm with far less complexity than exhaustive search algorithms. Simulation results indicate that the proposed method provides better energy efficiency than other WPCN optimization methods and the only time allocation method. Also, the presented algorithm balances the energy efficiency among users and simultaneously guarantees the minimum rate required for each user.