Vehicle Ad-Hoc Networks V2X Communication Protocol Based On Channel Propagation Model

With the accelerated development of the automobile industry and artificial intelligence,cars bring convenience and speed to people's lives,but also bring some traffic congestion problems.Vehicles Ad-Hoc Networks(VANETs)technologies are the most important part of Intelligent Transportation System(ITS),which have attracted extensive attention from researchers at home and abroad.The main task of VANETs exchange information between Vehicles to Vehicles(V2V)and Vehicles to Road Side Units(V2R).Through frequent interaction of information,reliable technical support is provided for the realization of unmanned driving on the road.Therefore,designing a good VANETs routing protocol in a complex urban environment is the core issue of this paper.For the complex and variable urban scene,this paper proposes an improved Nakagami-m channel propagation model to simulate the change of environment.The way of information transmission divides into Line of Sight(LOS)and Non-Line of Sight(NLOS)two transmission methods.Based on the constructed urban channel model,this paper proposes a V2 X Communication protocol based on Nakagami-m Outage Probability(VCNOP)based on Nakagami-m outage probability.The main working advantages are as follows:(1)The dynamic beacon mechanism is used to interact between vehicles.The dynamic beacon period is related to the speed of the vehicle and the density of the road where the vehicle is located.This mechanism effectively reduces the occurrence of broadcast storms.(2)Considering the route selection mechanism based on Road Side Units(RSU),the RSU is prioritized as a relay node when transmitting information,and the accuracy and real-time performance of the vehicle passing information is improved by RSU.(3)Consider the three factors of channel outage probability,relative speed,and normalized distance of the vehicle and neighbor nodes when selecting the relay node.The analytic hierarchy process is used to calculate the weight values of the three influencing factors,thereby increasing the probability of selecting the optimal next hop.During the simulation,SUMO is used to process the map of the selected real scene.The improved Nakagami-m channel model is simulated by routing performance,and the relationship between the communication channel outage probability and the channel signal-to-noise ratio is obtained.Then the channel simulation result is set as the simulationparameter of the routing protocol.On the PYNS3 simulation platform,VCNOP is compared with the classic routing protocols GPSR,GPCR,CAR and GSR.After comparison,the packet delivery ratio(PDR)and the average end-to-end delay(Average End to End)are obtained.Delay,AE2ED)routing performance.Through the analysis and comparison of experimental results,the VCNOP protocol proposed in this paper is completely adapted to the complex urban environment.