In this paper, we propose a single RF-chain multi-antenna full-duplex (FD) relay built with $b$-bit analog phase shifters and passive self-interference cancellation. The hardware complexity of the proposed FD relay with 2-bit quantized analog phase shifters is on the same order as the hardware complexity of a passive intelligent reflecting surface (IRS). Next, 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. We then 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 IRS. Our results show that the proposed relaying system with 2-bit quantized analog phase shifters can significantly outperform the IRS-assisted system. Intuitively, the IRS system is in disadvantage since there the total transmit power $P_T$ is used entirely by the source, whereas in the FD relaying system the total power $P_T$ is shared by the source and the FD relay in addition to the noise-cleansing process performed by the decode-and-forwarding at the FD relay.

翻译：在本文中,我们提出了一个单一的RF-链-多ANTAN(FD)中继系统,由美元比位模拟相位转换器和被动的自我干预取消。拟议的FD中继系统硬件复杂性与2位四分制模拟相位转换器的硬件复杂性与被动智能反射表面(IRS)的硬件复杂性相同。接着,假设FD中继器只被动地取消自我干预,我们得出一个由源、拟议FD中继器和目的地组成的系统的可实现数据率。然后,我们将拟议的FD中继系统的可实现数据率与同一系统可实现的数据率进行比较,但与理想的被动IRS取代的FD中继系统硬件复杂性相比较。我们的结果显示,2位四分制模拟相位转换器的拟议中继系统可以大大超过IRS辅助系统。直观地说,IRS系统处于劣势,因为由源、拟议中继系统完全使用美元P_T$,而在FD中继系统中继系统,由源和中继器在中继器中由源和中继器中继中继系统共享的美元T$P_T$。