Performance analysis of two-way opportunistic decode-and-forward based systems in Nakagami-m fading environments

This paper studies the performance of a two-way relay-based communication system with opportunistic relay selection in Nakagami-m fading environments. The authors consider a two-way wireless communication system where two nodes, acting as sources and using different modulation schemes for transmission, are unable to exchange data because of deep fading on their direct link and proceed via L relay terminals. They provide closed-form expression for the probability density function of the link between the 'selected' best relay and each source, and use this result to derive a closed-form expression for the average symbol error probability which, to the best knowledge of the authors, has never been done before. This result is further approximated for the high signal-to-noise ratio regions and used to develop closed-form expressions for the optimised power allocated to each node involved in the communication process. The authors asset their formulae with numerical results and interpretations to complete this work.