Theoretical Performance Analysis of Vehicular Broadcast Communications at Intersection and Their Optimization

Cooperative vehicle safety (CVS) systems are a key application of intelligent transportation systems using vehicle-to-vehicle (V2V) communications because they include many applications, such as cooperative collision warning. In CVS systems, vehicles periodically broadcast their information, e.g., position and speed, so that vehicles can track the positions of other vehicles. In this paper, we propose an optimization method for the broadcast rate in V2V broadcast communications at an intersection on the basis of theoretical analysis. We consider a model in which locations of vehicles are modeled separately as queuing and running segments and derive key performance metrics of V2V broadcast communications via a stochastic geometry approach. Since these theoretical expressions are mathematically intractable, we develop closed-form approximate formulae for them. Using them, we optimize the broadcast rate such that the mean number of successful receivers per unit time is maximized. Because of the closed form approximation, the optimal rate can be used as a guideline for a real-time control-method. We evaluated our method through numerical examples and demonstrated the effectiveness of our method.