Outage Probability of Two-Way Full-Duplex AF Relay Systems over Nakagami-m Fading Channels

In this paper, performance of two-way full-duplex cooperative systems under residual loop-interference (LI) is analyzed in terms of outage probability over Nakagami-m fading channels. At the relay node of the proposed system, physical-layer-network-coding technique and variable-gain full-duplex amplify-and-forward relaying method are combined for two-way transmission. End-to-end signal-to-interference-plus-noise-ratio (SINR) expression is derived for different power transmissions at the source and relay nodes. New exact outage probability expression is obtained in a single-integral form by using cumulative distribution function of the end-to-end SINR. The analytical results are verified by Monte-Carlo simulations. We also provide lower-bound and asymptotic expressions in closed-form for the outage performance. It is shown that the outage performance of the system is enhanced as long as either the transmit power or the efficiency of LI cancellation process increases. We also observe that the outage probability converges to an error floor due to the residual LI component at the source and relay nodes.