Outage Equivalence of Opportunistic Relaying and Selection Cooperation in Presence of Co-Channel Interference

In this paper, we investigate two different relay selection schemes, opportunistic relaying (OR) and selection cooperation (SC), for decode-and-forward (DF)-based relay networks consisting of a source, multiple relays, and a destination in the presence of multiple co-channel interferers, where each terminal has a single antenna and operates in a half-duplex mode. For the network, we first extend the conventional OR and SC to relay networks with the direct-path and multiple co-channel interferers, and obtain the exact and closed-form outage probability of the OR. Then, we show that the SC is equivalent to the OR in terms of outage performance for relay networks with the direct-path and multiple co-channel interferers. Finally, we show that the SC and OR are outage-optimal under the aggregate power consumption constraint at the relays for relay networks with the direct-path and multiple co-channel interferers.