Outage performance of dual-hop opportunistic relaying compared to a single-hop SIMO under Rayleigh fading

Cooperative relaying technique has shown potential in enhancing coverage area and reliability of transmission by forming virtual arrays. Opportunistic relaying tries to utilize best available channel between source and destination. Outage performance of relay based system can be improved through proper allocation of power and positioning of relay node. Analytical expression for outage probability for the opportunistic relaying scheme under consideration has been derived and its performance has been compared with an equivalent SIMO system performing selection combining. Results shows that opportunistic relaying outperform single-hop SIMO in high path-loss condition and performance of relay based system can further be improved by proper power allocation and relay positioning. The work presented in this paper is expected to be useful for the deployment of relay based system in various channel conditions.