Resource Allocation for AF Relaying Wireless-Powered Networks with Nonlinear Energy Harvester

This letter considers a relay-based wireless-powered communication network to assist wireless communication between a source and multiple users. In particular, the relay adopts a nonlinear energy model to harvest energy from a power beacon and subsequently uses it for information transmission over timedivision multiple access. Aiming at the maximization of end-toend (e2e) sum throughput, we formulate a novel optimization problem that jointly optimizes the power and time fraction for energy and information transmission. For a simple yet efficient solution for the nonconvex problem, we first convert it to a more computationally tractable problem and then develop an iterative algorithm, in which closed-form solutions are obtained at each iteration. The effectiveness of our proposed approach is verified and demonstrated through simulation results. Moreover, the results reveal that the source should transmit with its maximum allowable power budget to obtain the optimal e2e sum throughput.