Throughput Maximization in Bidirectional WPCN with Relay

A wireless powered communication networks (WPCNs) is a network model that transmits a power tranfer signal on a downlink and transmits an information signal on an uplink based on harvested energy through the received signal. In this paper, we assume a WPCN with one hybrid relay and multi-user pairs, and maximize the throughput of users in the network. We apply the harvest then transmit protocol, which is mainly used in the WPCN. We calculate rates of users and formulate sum rate problem. The convex optimization technique proves that the optimal value of the proposed problem can be obtained. Simulation results show that the sum rate through the proposed optimization problem achieves higher performance than the conventional scheme with equal time allocation.