Multipair Massive MIMO Two-Way Full-Duplex Relay Systems with Hardware Impairments

摘要

Hardware impairments, such as phase noise, quantization errors,non-linearities, and noise amplification, have baneful effects on wirelesscommunications. In this paper, we investigate the effect of hardwareimpairments on multipair massive multiple-input multiple-output (MIMO) two-wayfull-duplex relay systems with amplify-and-forward scheme. More specifically,novel closed-form approximate expressions for the spectral efficiency arederived to obtain some important insights into the practical design of theconsidered system. When the number of relay antennas $N$ increases withoutbound, we propose a hardware scaling law, which reveals that the level ofhardware impairments that can be tolerated is roughly proportional to$\sqrt{N}$. This new result inspires us to design low-cost and practicalmultipair massive MIMO two-way full-duplex relay systems. Moreover, the optimalnumber of relay antennas is derived to maximize the energy efficiency. Finally,Motor-Carlo simulation results are provided to validate our analytical results.