Performance Comparison Between A Simple Full-Duplex Multi-Antenna Relay And A Passive Intelligent Reflecting Surface

In this paper, we propose a single RF-chain multi-antenna full-duplex (FD) relay built with $b$-bit analog phase shifters. Assuming only passive self-interference cancellation at the FD relay, we derive the achievable data rate of a system comprised of a source, the proposed FD relay, and a destination. Next, we compare the achievable data rate of the proposed FD relaying system with the achievable data rate of the same system but with the FD relay replaced by an ideal passive intelligent reflecting surface (IRS). Our results show that the proposed relaying system with 2-bit quantized analog phase shifters can significantly outperform the IRS-assisted system.