Performance analysis of power-domain non-orthogonal multiple access for full-duplex two-way relaying

Non-orthogonal multiple has the potential to improve the connectivity of wireless networks by simultaneously allowing users and devices to access the wireless medium. Meanwhile, full-duplex communication can increase the spectral efficiency of the network as transmission and reception are concurrently performed. This article investigates full-duplex two-way relay communication relying on non-orthogonal multiple access in the power-domain. More specifically, users exchange superimposed signals and perform reception by utilizing echo-cancellation and successive interference cancellation. For this setup, an extensive theoretical analysis is conducted, in terms of outage probability, error probability, ergodic rate, and throughput. Furthermore, by using the Lagrangian multiplier, optimal transmit power, and power allocation coefficients are determined and the relay's position is optimized to improve network performance. Our theoretical findings are verified through Monte-Carlo simulations while significant performance gains in the optimized network case are observed.