Best-Relay Selection for Multi-Hop Vehicular Communication in Highways

Multi-hop relaying is an efficient transmission technique that splits the communication link between the source and the destination into several, possibly shorter, hops for extended coverage, improved reliability, and less power consumption. Previous works on multi-hop communications use the assumption of frequency-flat and quasi-static fading, which can be justified only for narrowband systems in stationary or quasi-static channels. In this paper, we extend multi-hop relaying into vehicular communication in highways.We propose a precoded transmission over multi-hop vehicle-to-vehicle links with time- and frequency-selective fading in highways. We investigate the performance gains where traveling vehicles are allowed to relay signals via neighboring vehicles to the final destination. With the aid of the precoded transmission and best-relaying vehicular selection, we succeeded to extract the rich diversity gains that are inherited in these types of doubly selective fading channels, through time, frequency, and space dimensions. We developed a mathematical model and derived a tight upper-bound expression for the pairwise error probability for future studies and analysis. Computer simulations are used to verify the correctness and accuracy of the derived analytical error.