On the Outage Performance of Two-Way Relay-Assisted Multiuser Vehicular Networks Over Double Nakagami-m Fading Channels

Ahstract- This paper investigates the outage performance of two-way relay-assisted vehicular communication systems. In particular, a multiuser vehicular system is considered wherein a source vehicle communicates bidirectionally with one of the several user vehicles via an amplify-and-forward relay vehicle. We opportunistically employ a selection strategy to select the best user vehicle which maximizes the end-to-end signal-to-noise ratio (SNR). By modeling vehicular links as double Nakagami-
$m$
fading, we first derive the distributions of the channel gain associated with the link between relay vehicle and the best selected user vehicle. Further, we deduce the closed-form tight lower bound on the overall outage probability (OOP) to offer an effective computation. We then provide the asymptotic OOP expression in the high SNR regime, and present the system's diversity order which depends on the involved fading severity parameters of communication links and number of user vehicles. Finally, we validate our analytical framework with simulations.