Performance Comparison of Outage-optimal Opportunistic Relaying
Generally,two single relay selection strategies,namely proactive and reactive opportunistic relay strategy,are included. In the system considered a direct transmission path,the performance comparison of these tw o schemes is less studied. In this paper, these tw o schemes are further investigated based on selective decode-and-forw ard( SDF) protocol. Accurate closed-form expressions for the outage probability of the tw o relay selection schemes are derived in detail. In the high signal-to-noise ratio( SNR) regime,approximate results of the tw o strategies' outage probability are also obtained. Theoretical analysis and numerical simulation results show that the outage probability performance of the reactive opportunistic relaying strategy is better than that of the proactive opportunistic relaying in the case of low SNR or having more the number of the relays in the high SNR regime.