Relay Selection in Dual-Hop Vehicular Networks

In this letter, we investigate cooperative diversity with relay selection over cascaded Rayleigh fading channels. In particular, we analyze the performance of a relay selection scheme for cooperative vehicular networks with the decode-and-forward (DF) protocol. Only the “best” relay, which satisfies an index of merit, is selected. We ignore the direct transmission between the source (S) and its destination (D), and assume that the destination has perfect knowledge of the S → R and R → D channel gains. We study the performance of the underlying scheme in terms of outage probability and investigate its achievable diversity order.