An efficient cooperative transmission scheme for vehicular communications

In vehicular communications, the current standards can be applied for safety-related message exchange but in the future world, other new applications like autonomous controlled vehicles require more reliability and capacity with small delay. Moreover, the harsh communication environment is one of the most difficult challenges. The line-of-sight (LOS) component of the signal in inter-vehicle connectivity is often blocked by obstacles. Consequently, the signal attenuation and packet loss rate due to the obstacles are significant. Therefore, this paper proposes a novel cooperative scheme combining distributed space-time block code (STBC), multiple access control and opportunistic routing without complicated routing algorithm for achieving the high reliability and reducing redundant packets for multi-hop vehicular communications on highway. From the simulation results, we can confirm that the proposed method can achieve reducing the redundant packets with keeping the significant improvement of packet loss rate by limiting the number of repetition of the same packet transmission at each node.