Research On Dynamic Adaptive Cooperative Communication Scheme In VANET

The related applications of VANET have great influence on the development of intelligent transportation.It can solve the efficiency and safety of vehicle travel,but also provide on-board entertainment.The distribution characteristics of Road Side Unit and the limitations of its communication range are not enough to meet the requirements of vehicle users to connect to the network.The cooperative communication scheme based on content download in VANET not only meets the needs of vehicle users for security information services,facilitates the implementation of network value-added services,but also improves the performance of VANET.In intermittently connected vehicular network,how to meet the needs of users for reliable and stable network has become a current research hotspot.However,it is worth pointing out that the application of 5G promotes the integration of new communication technologies and VANET.In addition,the cooperative communication strategies in vehicle networks are based on DSRC technology.The technology is difficult to implement under the condition of perfect base station deployment in our country,which l im its the development of domestic intelligent network vehicles.Moreover,considering that the signals of vehicles are shielded or disturbed under the actual road environment(overpass,culvert and other building occlusion,etc.)in our country,which causes vehicles unable to connect to the network in real time.Firstly,this thesis divides the current cooperative communication schemes in VANET into three categories,analyzes and compares the schemes in the aspects of cooperative conditions,communication modes and cooperative strategies,and points out the advantages and disadvantages of different schemes.Secondly,the classical cooperation scheme and system model are introduced.Then this thesis designs a new cooperation scheme and verifies the proposed cooperation scheme through VANET system simulation platform built by MATLAB.The main contributions of this thesis include:For the single system model,this thesis proposes a BCDS.According to the detailed planning of backward-backward-forward assistance vehicles for the blind area between the RSUs.At the same time,it provides detailed theoretical analysis and derives the expression of user achievable throughput.Simulation and numerical results show that the scheme is feasible and improves the throughput of user acquisition.Aiming at the problem of signal shielding or interference caused by actual road environment in our country.On the basis of the above research,we propose a DABCCS.The establishment of the system model takes into account the fading and interference in the channel,which can meet the research needs of real road scenarios in China.The scheme focuses on wireless access technology and assist in vehicle selection strategies,and use ultra-dense networking technology to construct dynamic self-organizing network topology of the vehicle network.Vehicles are assisted by vehicle distribution characteristics and mobility planning,and the optimal SINR value of vehicle communication link is used as the basis for selecting the best assisted vehicle.The simulation results show that the proposed DABCCS can effectively satisfy the requirement of stable and reliable network connection for driving vehicles at anytime and anywhere.