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.

I. Introduction

Vehicular ad-hoc networks (VANETs) [1] are a crucial component of the intelligent transportation systems which involve the application of advanced information processing, communications, sensor, and control technologies in an integrated manner to improve the functioning of the transportation system. VANETs have received much attention in recent years with their potential of enormous improvements in the road safety, and elimination of the excessive cost of traffic collisions. Besides safety improvement and traffic management, other applications, such as audio/video streaming, real-time gaming and high-speed internet access are also envisioned.