Resource Allocation in Full-Duplex Multiuser RIS-Assisted Wireless-Powered IIoT Networks

This article examines radio resource allocation in a full-duplex (FD) reconfigurable intelligent surface (RIS)-assisted wireless-powered (WP) industrial Internet of Things (IIoT) communication network. The system model includes an FD access point (FD-AP) that communicates with FD energy harvesting (EH) mobile users (MUs), referred to as an FD-FD RIS-assisted WP-IIoT network. The FD-AP is equipped with two sets of multiple antennas: one set for downlink (DL) energy beamforming and another for uplink (UL) information signal reception. The FD-MUs have one antenna for DL energy signal reception and another for UL information transmission. This article addresses the UL sum-rate maximization problem for the FD-FD RIS-assisted WP-IIoT system by jointly optimizing the RIS phase shift and power resources. Additionally, this article presents two benchmarks as specific cases of the FD-FD RIS-assisted WP-IIoT system model, namely the following: 1) FD-HD RIS-assisted WP-IIoT network: FD AP and half-duplex (HD) two MUs groups and 2) HD-HD RIS-assisted WP-IIoT network: HD AP and HD MUs. The numerical results demonstrate that the FD-FD system outperforms both benchmarks in the low transmit power regime. Also, compared to the baseline non-RIS-assisted WP-IIoT network, the RIS-assisted WP-IIoT network achieved a significant UL sum-rate gain.