Performance analysis and optimization of two-way cooperative communications in inter-vehicular networks

In this paper, we investigate a bidirectional communication between two vehicles where there is no direct link between them and other vehicles or roadside access points (AP) act as relays employed to help the communication. The statistical model of source-relay and relay-destination links are assumed cascaded Nakagami under vehicle-assisted scenario, and is assumed Nakagami under AP-assisted scenario. In both scenarios source-destination channel model is considered cascaded Nakagami and the relaying protocol is amplify and forward (AF). We derive a closed form expression for symbol error rate (SER) and present diversity analysis. We demonstrate that the cooperative scheme is able to achieve maximum diversity order in multi-relay cascaded Nakagami fading channels then we analyze and optimize the power allocated to the broadcasting and relaying phases. Optimum power allocation yields performance improvement 2dB to 7dB depending on the relay location and deployed modulation scheme.