Mitigating error propagation in cooperative intervehicular communications

Cooperative wireless communication has attracted intense interest as an alternative way to multiple-antenna systems to obtain spatial diversity. In this paper, we investigate the performance of a vehicle-to-vehicle cooperative scheme where another vehicle in the vicinity of the source vehicle acts as a relay. The underlying source-to-relay, relay-to-destination, and source-to-destination links are modeled as cascaded Nakagami-m fading which provides a realistic description of an intervehicular channel. Unlike the most studies on cooperative intervehicular communications in the literature which are based on analog relaying, we employ digital relaying approach and investigate the performance of the techniques developed for mitigating error propagation in decode and forward based wireless relay systems such as maximum likelihood, cooperative maximal ratio combining, link adaptive relaying, virtual noise based detection and soft information relaying. Simulation results show that detection schemes with these techniques outperform the noncooperative system that involves direct transmission between the source and destination terminals and overcome the diversity gain reduction due to error propagation.