Research On Inter-vehicle Communication Channel Modeling In Vehicular Ad Hoc Networks

Vehicle-to-Vehicle(V2V)communication is an important foundation of Vehicular Ad hoc Network(VANET),so the researches into its wireless channel characteristics will play a great role in guiding the design of V2V communication system.There are some similarity between V2V communication and traditional cellular communication,such as multipath fading.However,there are many differences which can not be ignored among them,such as the height of transmitting antenna and the range of communication distance.Moreover,both transmitting terminal and receiving terminal of V2V communication are in motion.As a result,the traditional channel modeling methods can not be adopted directly.Instead,a proper channel model based on its specific characteristics need to be established.Firstly,the differences in wireless channel between V2V communication and the traditional cellular communication as well as the usual channel modeling methods were summarized in the thesis.Knowledge of ray-tracing was also introduced.Besides,a Vertical-Plane-Launch(VPL)technique was introduced in detail,which was utilized to model the wireless channel to gain the space-time-frequency characteristic of wireless channel in V2V communication.Secondly,the simulations and of wireless channel under urban environment and high way environment were completed in the thesis.Moreover,the dispersion parameter information of time,angle and frequency which were acquired from the established channel model were analyzed.This work were completed respectively in three typical scenes under urban environment,which were scene of crossroad,scene of one same street and scene of being separated by a block.The influence of buildings on the propagation of radio were mainly considered under urban environment and the influence of different building materials on signal intensity was also simulated.Under the high way environment,the influence of vehicles in the mobility model which had been set,especially the big vehicles,were considered.Moreover,the power loss of different effects,such as reflection and diffraction was compared.The upper limit of the times of reflection and diffraction was also figured out to reduce the unnecessary ray branches and improve the running efficiency of algorithm.In the last,the three important modules of implementation of channel modeling were introduced in detail in the thesis.Multi-thread programing was used to improve running speed of algorithm and the relationship between running speed and the numbers of thread was simulated.