Two-Way Relaying under the Presence of Relay Transceiver Hardware Impairments

TL;DR

This paper investigates how hardware impairments in transceivers affect two-way relay communication systems, providing analytical expressions for outage and error probabilities, and highlighting the persistent performance limits due to impairments.

Contribution

It offers the first detailed analysis of transceiver impairments in two-way relaying, deriving exact and asymptotic performance metrics under hardware imperfections.

Findings

Non-zero lower bounds on outage and symbol error rates at high power

Impairments prevent error rates from approaching zero, unlike ideal hardware cases

Analytical expressions for outage probabilities and symbol error rates

Abstract

Hardware impairments in physical transceivers are known to have a deleterious effect on communication systems; however, very few contributions have investigated their impact on relaying. This paper quantifies the impact of transceiver impairments in a two-way amplify-and-forward configuration. More specifically, the effective signal-to-noise-and-distortion ratios at both transmitter nodes are obtained. These are used to deduce exact and asymptotic closed-form expressions for the outage probabilities (OPs), as well as tractable formulations for the symbol error rates (SERs). It is explicitly shown that non-zero lower bounds on the OP and SER exist in the high-power regime---this stands in contrast to the special case of ideal hardware, where the OP and SER go asymptotically to zero.