Reliable Transmission of Energy Harvesting Full-Duplex Relay Systems with Short-Packet Communications

Energy harvesting (EH) from radio frequency (RF) signals provides a promising approach for supplying sustainable and convenient energy to low-power Internet of Things (IoT) devices. In this work, we investigate short-packet communications in a full-duplex (FD) relay system, where RF signals from a source are utilized to power an energy-constrained relay through the time switching protocol. Specifically, hardware impairments in each node and residual self-interference caused by FD are jointly considered. To ensure reliable transmission, two antennas are symmetrically arranged according to the position of the relay station, both of which are used for energy harvesting. Furthermore, we explored two practical schemes based on symmetric channel correlation, i.e., an independent channel for energy harvesting and an identical channel for energy harvesting. For both scenarios, we derive closed-form approximations for the overall average block error rate (BLER) and effective throughput. The validity of our analysis is confirmed through computer simulations, demonstrating that the proposed scheme enhances the reliability and throughput of the system compared with the existing scheme in the literature at low transmission rates and transmit signal-to-noise-ratios (SNRs).