Performance analysis of full-duplex AF relaying with transceiver hardware impairments

G. GONZÁLEZ; F. GREGORIO; J. E. COUSSEAU; T. RIIHONEN; R. WICHMAN

Oulu

Congreso; European Wireless Conference 2016; 2016

We propose a joint widely-linear I/Q imbalancecompensation and self-interference (SI) cancellation scheme foramplify-and-forward (AF) full-duplex (FD) relay transceivers.Furthermore, we study the bit-error rate (BER) performanceof a complete two-hop link considering hardware imperfectionsin transceiver electronics. Especially, if the relay gain increases,the signal-to-noise ratio (SNR) atthe destination becomes higherbut this also increases the SI level due to the FD operationand, as a consequence, the signal-to-interference-plus-noise ratio(SINR) at the relay input decreases. To settle this trade-off, wefind numerically the optimal input back-off (IBO) for the relaypower amplifier (PA) maximizing the BER at the destination.The numerical results show that the optimal IBO depends onthe target BER level and the PA nonlinearity. They also showthat the distortion from the PA dominates the other hardwareimpairments at high SNR. Finally, we show that the proposedcancellation scheme can completely eliminate the I/Q imbalance,even with mixers that have low image rejection ratio.