Fairness enhancement in dual-hop wireless powered communication networks

This paper considers a dual-hop wireless powered communication network (DH-WPCN), where the communication between a hybrid access point (HAP) and a number of users is assisted by energy-limited relays. In order to power relays for assisting the 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 with an amplify-and-forward (AF) relaying approach. Under this setup, we study the problem of maximizing the minimum throughput among network users. The objective is to optimize time allocations for energy and information transfer so as to ensure throughput fairness and at the same time optimize the sum-throughput. Simulation results confirm the effectiveness of our proposed fairness enhancement algorithm and reveal the trade-off between sum-throughput and fairness.