Outage Analysis of N^{th}-Best DF Relay Systems in the Presence of CCI over Rayleigh Fading Channels

This letter investigates the outage behavior of a dual-hop N^th-best decode-and-forward (DF) relay system in which the relay and the destination undergo independent sources of co-channel interference (CCI). The fading envelopes associated with the desired and interfering users are assumed to follow independent but non-identically distributed (i.n.d.) Rayleigh fading models. Through the analysis, exact and approximate outage probability are derived based on which the diversity order and coding gain are obtained. Our findings suggest that the diversity order linearly increases with the number of relays and decreases with the order of the relay. Furthermore, results reveal that the system is still able to achieve full diversity gain in the presence of finite number of interferers with finite powers. The analytical results are supported and validated by Monte-Carlo simulations.