Intelligent-Reflecting-Surface-Aided Bidirectional Full-Duplex Communication System With Imperfect Self-Interference Cancellation and Hardware Impairments

In this article, we combine two new technologies [full-duplex (FD) transmission and intelligent reflecting surface (IRS)] in a wireless communication system for investigation. Specifically, we evaluate the performance of an IRS-aided bidirectional FD communication system in a practical scenario where imperfect self-interference (SI) cancellation and hardware impairments (HIs) are taken into consideration. We successfully derive the closed-form expressions of ergodic capacity (EC) and symbol error rate (SER) of the IRS-aided FD-HI system over Rayleigh fading channels. We confirm the correctness of the derived expressions via Monte-Carlo simulations. To clarify the effects of residual SI and HIs, we compare the performance of the IRS-aided FD-HI system with that of the IRS-aided FD-ideal hardware (ID), half-duplex (HD)-HI, and HD-ID systems. Numerical results clarify a strong impact of residual SI and HIs on the EC and SER of the IRS-aided FD-HI system. Thus, the EC and SER of the IRS-aided FD-HI system go to the saturated values in a high signal-to-noise regime even with a large number of reflecting elements in the IRS. Therefore, depending on the residual SI and HI levels as well as the requirements about the EC and SER in practice, we can use appropriately the transmit power of terminals and number of reflecting elements in the IRS for enhancing the performance and saving the energy consumption of the IRS-aided FD-HI system.

Automated summary

This article investigates the combination of two new technologies, full-duplex (FD) transmission and intelligent reflecting surface (IRS), in a wireless communication system. The performance of an IRS-aided bidirectional FD communication system is evaluated in a practical scenario, considering imperfect self-interference (SI) cancellation and hardware impairments (HIs). Closed-form expressions for the ergodic capacity (EC) and symbol error rate (SER) of the IRS-aided FD-HI system over Rayleigh fading channels are derived, and their correctness is verified through Monte-Carlo simulations. The performance of the IRS-aided FD-HI system is compared with that of other systems, including IRS-aided FD-ideal hardware (ID), half-duplex (HD)-HI, and HD-ID systems, to clarify the effects of residual SI and HIs. The numerical results demonstrate that residual SI and HIs have a strong impact on the EC and SER of the IRS-aided FD-HI system. Therefore, depending on the residual SI and HI levels and the requirements for EC and SER in practice, the transmit power of terminals and number of reflecting elements in the IRS can be appropriately adjusted to enhance system performance and save energy consumption.