Research On Characteristics Of Vehicle Scattering Channel In Vehicular Network

Vehicle-to-vehicle(V2V)communication is regarded as the basic and core technology for road traffic safety and intelligent green transportation,which has attracted attentions from both industry and academia areas.However,the most common scenarios of actual traffic flows,where other vehicles lie between transmitting and receiving vehicles,lack of quantitative research and analysis.Such behavior deviates from the actual channel modeling and has a negative impact on the design of upper-level protocols in the wireless communication system.Focusing on the deterministic channel modeling of the V2 X,this thesis quantitatively studies the influence of vehicle scattering effect on channel characteristics.The main work of this thesis is as follows:Firstly,the thesis introduces the background and research status of V2 V communications and V2 V wireless channel modeling.Then it gives a comprehensive review of the V2 V channel measurement and channel modeling in the case of vehicle obstruction.The similarities and differences between V2 V channels and traditional cellular channels are compared from several aspects.The necessity of V2 V channel modeling is addressed.Secondly,this thesis compares and analyzes the pros and cons of various V2 V channel modeling methods.Hence,the ray-tracing algorithm is selected to simulate vehicle scattering models in V2 V systems.Related theories and traditional algorithms on ray-tracing techniques in vehicular network are further studied.Thirdly,considering three typical V2 V communication scenarios,i.e.,no vehicle obstruction,small vehicle obstruction and large vehicle obstruction,their corresponding deterministic channel models are constructed based on the ray-tracing algorithm.Also,we theoretically analyze the influence of scattering effects of obstructing vehicles on the V2 V channel characteristics,such as path-loss.Simulations verify the correctness of theoretical analysis.In addition,the influence of the change of the relative lateral position between the vehicles on the channel model of large vehicle occlusion is studied.Based on the probability distribution of the relative lateral position between the front and rear vehicles in the same lane,the closed expression of the probability distribution of channel intensity is derived.Finally,researching on single antenna V2 V channel models in cases of no vehicle obstruction,small vehicle obstruction and large vehicle obstruction are extended to their counterpart of multiple-input multiple-output(MIMO)systems.The corresponding MIMO channel capacities are calculated.Based on the simulation results,the influences of the receiving signal-to-noise ratio,adjacent element spacing of an antenna array and the array structure on channel capacities are analyzed theoretically.By comparing our V2 V channel model capacities to other measurement results in similar scenarios,the accuracy of our simulations shows the correctness to certain extend.