Research On Trunking Transmission Strategy Based On Clustering In Cooperative Vehicle Communication System

Since With the accelerated development of automobile industry and artificial intelligence network,automobiles not only bring convenience to people's life,but also bring a series of urban traffic problems.Vehicles ad-hoc Networks(VANETs)is an important part of Intelligent Transportation System(ITS)and has attracted the attention of scholars at home and abroad.Due to the characteristics of vehicle network,such as strong node mobility,rapid change of network topology,and limited path of nodes,the previous VANETs clustering algorithm is no longer applicable to vehicle network.In this case,in order to make the vehicle network have an efficient,stable and reliable clustering algorithm,the main research contents of this paper are as follows:First,the fundamental theories of cooperative vehicular communication system are outlined,including clustering algorithm and cooperative communication technology.Second,although D2D(Device-to-Device)cooperative vehicular communication in the cellular network can improve the communication system capacity,it fails to fully consider the difference of vehicle speed and thus limit the data transmission rate.In this paper,a cooperative relay transmission strategy for D2 D vehicular communication based on speed clustering is proposed.The strategy divides the velocity intervals according to the vehicle speed,vehicles in each interval forms a cluster,and the cluster head is selected through the vehicle average speed and weighted values.In the case,D2 D relay cooperative communication transmission with AF/DF protocol is adopted for each vehicle in the cluster.Simulation results show that within a certain speed range,the replacement frequency of cluster-head vehicles decreases,the stability within the cluster increases,and the transmission rate can be improved by using D2 D relay AF/DF cooperative transmission.Third,to solve the problem of unstable link and low reliability in vehicle ad hoc network,we propose a relay forwarding scheme based on weighted clustering.In the scheme,we first present the weighted cluster algorithm to improve the stability of the communication link.We introduce the relative vehicular confidence distance,relative achievable rate and connectivity as clustering properties and select the optimal cluster head as a relay in the ascending order of their property weight.And then,we adopt the bidirectional DF protocol to enhance the reliability of vehicle to vehicle communication under the Na Kagami-m channel.Numerical results show that the stability of the proposed algorithm cloud improve 8 seconds compared by the lane based cluster algorithm.The outage probability of bidirectional DF protocol reduces 6% compared by AF protocol.