Throughput Maximization in Dual-Hop Wireless Powered Communication Networks.

In this paper, we study a dual-hop wireless powered communication network, where the communication between a hybrid access point (HAP) and a number of users is assisted by energy-constrained relays, which need to harvest energy from radio-frequency (RF) signals broadcast by the HAP. In order to power the relays for assisting the uplink communication, the HAP broadcasts a dedicated energy signal in the downlink. Each relay harvests energy from this signal and utilizes the harvested energy in forwarding its corresponding user's data to the HAP. In downlink communication, relays exploit a power-splitting strategy and use the information signal broadcast by the HAP for both energy harvesting and information forwarding. Under this setup, we are interested in maximizing the total uplink and downlink throughput. First, we propose an algorithm for solving uplink throughput maximization problem, which optimizes time allocations for energy and information transfer. For downlink throughput maximization, we obtain a near-optimal solution by optimizing time allocations and power splitting ratios iteratively. Finally, we conduct numerical simulations to evaluate the performance of the proposed algorithms. [ABSTRACT FROM PUBLISHER]