Joint Beamforming and Resource Allocation for Multi-User Full-Duplex Wireless Powered Communication Networks

In this paper, we investigate a wireless powered communication network (WPCN) protocol in which mobile stations (MS) with energy harvesting (EH) communicate with a full-duplex access point (FD- AP). The FD-AP is equipped with multiple antennas, while MSs have a single antenna and operate in half-duplex (HD) mode. The MSs are assigned two groups according to the time slot and their access channel state for either uplink or downlink communication with the FD-AP. Channel assignment, time resource allocation, and power allocation is jointly optimized for maximizing the sum-rate. An iterative algorithm based on the relationship between rate and minimum mean squared error (MMSE) is proposed to maximize the sum-rate by examining the Lagrangian problem. The proposed algorithm for FD-WPCN is compared to its HD counterpart. It is shown from simulation results that the proposed FD-WPCN scheme outperforms the HD mode when low transmit power is used although the FD-WPCN performance is degraded at high transmit power regime due to the presence of residual self- interference (RSI) at the FD-AP node.