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.
Matthaiou, M., Papadogiannis, A., Björnson, E., & Debbah, M. (2013). Two-Way Relaying under the Presence of Relay Transceiver Hardware Impairments. IEEE Communications Letters, 17(6), 1136-1139. https://doi.org/10.1109/LCOMM.2013.042313.130191