Performance Analysis of Two-Way Selective Amplify-and-Forward Relaying Systems in the Presence of Co-Channel Interference over Nakagami-m Fading Channels

The performance of two-way interference-limited amplify-and-forward selective combining relaying systems over independent and non-identically distributed (i.n.i.d.) Nakagami-m fading channels is investigated. Tight lower bounds on the end-to-end outage probability and symbol error rate are derived in closed-form. An asymptotic analysis at high SNRs is done to derive useful expressions for the diversity order and coding gain. Some practical special cases (for example: interference free, infinite power, and Rayleigh fading channels cases) are also studied. Subsequently, an outage minimization problem for three practical scenarios is formulated and solved, analytically. They are power allocation under fixed relay location, relay position optimization under fixed power allocation and joint power allocation and relay position optimization problems. The numerical results confirm the correctness and accuracy of derivations and provide important physical insights into the impact of model parameters on the system performance. For instance, it is demonstrated that the first and third optimization scenarios offer significant performance enhancement over the second optimization scenario.