Outage Probability Equivalency of Three Typical Relay Selection Schemes for Selective DF Relay Networks with Selection Combining

Outage probability of selective decode-and-forward (DF) relay networks with different relay selection schemes are usually analyzed separately in the literature. In this paper, for selective DF relay networks with selection combining technique, we show that, the three typical relay selection schemes (named as proactive, reactive, and backward reactive relay selection scheme, respectively) are all equivalent with each other in term of outage probability of the networks. Furthermore, this outage probability equivalency is valid even when the wireless channels in the networks are non-identical, interrelated, and with different fading models. Hence, outage probability of a selective DF relay network with one particular relay selection scheme could be obtained indirectly, if necessary, by obtaining the outage probability of the network with another equivalent relay selection scheme but with lower computing complexity.