Performance analysis of cooperative communications at road intersections using stochastic geometry tools

Vehicular safety communications (VSCs) provide relevant solutions to avoid congestion and road accidents, more particularly at road intersections since these areas are more prone to accidents. In this context, one of the main impairments that can affect the performance of VSCs is interference. In this paper, we study the performance of cooperative transmissions at intersections in presence of interference for VSCs. We use tools from stochastic geometry, and model interferer vehicles locations as a Poisson point process. First, we calculate the outage probability for a direct transmission when the receiving nodes can be on the road (as vehicles), or outside the road (as infrastructures). Then, we analyze the outage probability performance of a cooperative transmission scheme. The analysis takes into account two dimensions: the decoding strategy at the receiving nodes, and the vehicles mobility. We determine the optimal relay position under different traffic densities and for different vehicles mobility models. We also show that the outage probability does not improve after the number of infrastructure relays reach a threshold value. Finally, we show that the outage probability performance of VSCs is higher at intersections than on highways. We validate our analytical results by Monte-Carlo simulations.