Opportunistic Relaying for Two-Way Relay Transmission with Asymmetric Traffic Requirements

This paper investigates opportunistic relaying of a half-duplex two-way relay network, where two source users exchange information through a shared amplify-and-forward (AF) relay which is opportunistically selected from a set of candidates. Unlike existing works, in our considered network scenario, the two source users have different target rates. A novel protocol for opportunistic relaying is developed, which adaptively switches between the max-min and the pure-max policies according to the information of system traffic. The performance of the new relaying strategy in terms of the system outage probability is analyzed over Rayleigh fading channels. Simulation results demonstrate that the proposed protocol can implement opportunistic relaying efficiently, and can achieve significant performance gains in terms of the outage probability across all traffics.