Research On Safety Data Transmission Of Vehicle System Under C-V2X

In Cellular Vehicular-to-Everything(C-V2X)systems,vehicle safety-related applications have provided services for drivers such as danger warning and route optimization,which play an important role in improving traffic safety and travel efficiency.Considering strict requirements of delay and reliability for vehicle safety data transmission,we address issues in implementing vehicle safety data transmission under urban and suburban scenarios,respectively.First,the limited bandwidth resources and computing ability of base stations may easily cause base station overload in heavy traffic scenarios and affect delay and reliability for vehicle safety data transmission in the city.Moreover,fast-moving vehicles and complex road networks will lead to frequent reconstruction of net-work topology for vehicle communication,and thus resulting in a large amount of calculation and signaling overhead.In order to improve the performance degradation of data transmission caused by the instability of the vehicle communication network topology in urban scenarios,we establish a vehicular full-duplex device-to-device(FD-D2D)communication model with cluster as the core,and propose a FD-D2D vehicular communication resource management scheme based on hypergraph clustering(HG-C)and interference limited area(ILA)theory.In the proposed scheme,the degree of link dependence(DLD)and computation ability of vehicle users(VUE)are utilized to improve the cluster survival time and reduce the BS overhead.Meanwhile,the dynamic power control and the sharing area mapping are used to assist the BS to allocate resources,reduce co-frequency interference between V-D2D(vehicular device-to-device)links and V-D2D links to the cellular link that reuse the same frequency,and improve spectrum efficiency.Second,the transmission power of the multicast for vehicle safety data is higher in the suburbs.This is because the coverage radius of suburbs base stations is much larger than that of urban areas.The multicast service often wastes resources of the base station attributed to the VUE of the worst channel conditions,which results in reduced base station load capacity.In order to reduce the power consumption of the base station for safety data multicast,we combine the multicast with V-D2D communication to present a two-stage multicast transmission of vehicle security data(TSMT-VSD)scheme under cellular networks.In the relay selection strategy of TSMT-VSD scheme,the selected relay range is first determined on the premise of saving total power consumption.The optimal multicast radius with the lowest BS power consumption is calculated,and then the vehicle closest to the radius is selected as the relay to reduce the power consumption of base stations.Moreover,based on the social attributes of relays,an asymmetric evolutionary game model between BS groups and relay groups is established,and a reward and punishment mechanism for dynamic redistribution of relay entertainment data transmission power without affecting secure data transmission is designed to suppress the selfishness of the relay and ensure the reliability of the TSMT-VSD scheme.Finally,the VISSIM software is used to model urban and suburban traffic scenarios,which generates real-time traffic flow data.Here,the two sets of real-time traffic flow data were utilized to verify the proposed FD-D2D resource management scheme and TSMT-VSD scheme.The simulation results are shown that the resource management scheme for FD-D2D vehicular communication in the city utilizing hypergraph clustering(HG-C)and interference limited area(ILA)theory reduces significantly the network topology management workload of BS and improves effectively the spectrum efficiency.Moreover,the TSMT-VSD scheme utilizing the only optimal relay selection mechanism and the reward and punishment mechanism,which reduces drastically the power consumption of the base station multicast service on the premise of ensuring two-stage multicast reliability of secure data.