Road traffic safety is a crucial issue, and more specifically at road intersections. At the same time, vehicular communications (VCs) are attracting a great attention thanks to their useful safety applications. In this paper, we study the performance of VCs at intersections, in the presence of interference when the communication system implements a non-orthogonal multiple access (NOMA) scheme. First, we derive the outage probability and the average achievable rate for a scenario involving a source node and two destination nodes, when the destination nodes can be either on the roads or outside the roads. Then we extend the derivations for K destination nodes. Closed form expressions are obtained for the outage probability and quasi-closed form expressions are obtained for average achievable rate. The analysis takes into account both perfect and imperfect successive interference cancellation (SIC). We show that the outage probability increases and the average achievable rate decreases when vehicles move toward the intersection. We also compare the performance of VCs at intersections and at highways, and show that the performance of VCs at intersections is worse than at highways. We compare NOMA with orthogonal multiple access (OMA) in VCs, and show that NOMA outperforms OMA in terms of outage probability and average achievable rate. We also show that the benefit of NOMA over OMA becomes greater for high data rates. However, we show that NOMA performance decreases drastically when the system parameters do not respect certain conditions. All the analytical results are validated by Monte-Carlo simulations.

道路交通安全是至关重要的问题，尤其是在道路交叉口。同时，由于其有用的安全应用，车辆通信（VC）引起了极大的关注。在本文中，我们研究了在通信系统实施非正交多址（NOMA）方案时存在干扰的情况下，交叉口处VC的性能。首先，当目标节点可以在道路上或道路外时，我们推导涉及一个源节点和两个目标节点的场景的中断概率和平均可实现率。然后我们扩展对K的推导目标节点。对于停机概率，获取封闭形式的表达式；对于平均可实现速率，获取近似封闭的形式的表达式。该分析考虑了完美和不完美的连续干扰消除（SIC）。我们表明，当车辆向十字路口行驶时，停电概率增加，平均可达到率降低。我们还比较了交叉路口和高速公路上的VC的性能，结果表明，交叉路口的VC的性能比高速公路要差。我们将NOMA与VC中的正交多路访问（OMA）进行了比较，并显示出NOMA在中断概率和平均可实现率方面优于OMA。我们还表明，对于高数据速率，NOMA优于OMA的好处变得更大。然而，我们显示，当系统参数不遵守某些条件时，NOMA性能将急剧下降。所有分析结果均通过蒙特卡洛仿真验证。