Research And Simulation On VANET Wireless Communication Channel Synoptic Model

The vehicle nodes with high-speed mobility,which results in the dynamic change of network topology,is the main characteristic of the inter vehicles communication.As the physical medium of communication,wireless channel influences the performance of wireless communication network.These characteristics make it particularly challenging for vehicle radio signal propagation and channel modeling.The research of wireless channel has received extensive attention.According to the measured data,many researchers have proposed the corresponding channel model.802.11 p offers a standard for the implementation of wireless channels,and some channel models are adopted into the standard.The wireless signal is affected by various aerosol systems when it propagates in the air medium.Special weather also has a great impact on driving safety.Therefore,it is necessary to model and calculate the channel propagation under special weather conditions.Many existing channel models are aimed at conventional weather,because the experimental data in conventional weather conditions are easy to measure.However,it is difficult to obtain actual data in severe weather conditions.Therefore,on the basis of the existing channel model,this paper proposes a channel model which can be used to calculate the special weather conditions.The calculation process of this model is divided into two steps: The first step is to calculate the influence coefficient of the special weather on the 5.9GHz frequency band signal;In the second step,the influence coefficient is introduced into the original conventional weather model to calculate the propagation of the wireless signal power in special weather conditions.After the theoretical model is proposed,the simulation experiments are carried out to illustrate the influence of weather conditions on wireless signals.The simulation experiments in this paper mainly choose two common driving scenes: straight road with line of sight and intersection with no line of sight.The propagation of vehicle wireless signals is affected by many factors,including road conditions,road width,vehicle position,surrounding buildings,roadside signs,vegetation,weather,etc.This paper first choose the simple driving environment,and analyze the influence of different factors on the wireless signal power distribution.Such as,changing the emission coefficient of the road surface,adjusting the width of the road surface and changing the position of the vehicle.Then,the influence of sand and snowfall on the wireless signal are added to the model.This increases the use scope of the model,so that,the channel model can be applied to a wide variety of scenarios.In the meteorological model,this paper chooses the dust charged model and the snowfall model.In the dust model,this paper focuses on the influence of visibility without considering the other factors of the particles.Due to the movement of dust particles,low visibility dust has a great influence on the power of the electromagnetic wave.Moreover,the farther the wireless signal travels,the greater the impact.In the snowfall model,snowfall is the main factor affecting the signal power.The influence of snowfall with different water content on the signal is also different.The effect of dry snow is more pronounced than wet snow.The greater the snowfall in unit time,the more obvious impact on power.