车辆间的传输干扰在车辆自组织网络中是影响车辆间通信质量的一个重要因素,车辆在同时发送信号过程中会对周围车辆接收的信号产生影响,从而对网络连通性预测产生更大的挑战。根据车辆密度及交通流量,提出一种基于Nakagami的车载网络连通预测模型。该模型采用Nakagami分布特性描述信号传输过程中的衰落信道,通过接收信号功率概率密度函数及信噪比获得车辆间连通概率。仿真结果表明,在传输信号车辆比例达到饱和之前,通过提高传输信号车辆比例可以提高连通概率,但若此比例超过了饱和值则会对车辆连通产生消极的影响。
The inter-vehicle transmission interference is one of the key factors to impact the communication performance of vehicular Ad Hoc networks. When vehicles send signals at the same time, it will inevitably have an impact on the surrounding vehicles, which has a negative effect on network connectivity prediction. According to vehicle density and traffic flow, a vehicular network connectivity prediction model was presented based on Nakagami distribution. The Nakagami distribution was used to describe the fading channel in the signal transmission process.Form expression of the inter-vehicle connectivity probability was also derived with power probability density function and signal to noise ratio of received signals. Simulation results show that connectivity probability can be well improved with larger ratio of vehicles which transmit signals before the ratio reaches the maximum. However, negative effect will take place on vehicular connectivity when the ratio exceeds the maximum value.