Research On Information Security Transmission Strategy In Cooperative Vehicular Communication System

With the rapid development of the Internet-of-vehicles technology,more and more devices will be connected to the vehicular network in the future,which will lead to the explosive growth of traffic.The relay cooperative communication in vehicular communication system can reduce traffic congestion and improve the coverage ability and communication quality-of-service through mass network connection.Here,the relay cooperative communication is especially fitted for the complex geographical environment and the occlusion of tall buildings in the urban traffic environment.Moreover,the openness of wireless transmission environment will make the communication system subject to malicious eavesdropping user attack,which seriously affects the security performance of vehicular communication system.Therefore,this is a key issue that how to realize efficient transmission of information in the cooperative vehicular communication system meanwhile ensuring the safety of the communication system,which needs to be solved in the present cooperative vehicular communication system.The main contents of this dissertation are described as follows:First,the basic theory of cooperative vehicular communication system is summarized.It includes the network architecture of vehicular communication system,the technology of relay cooperative communication,non-orthogonal multiple access(NOMA)cooperative communication technology and reconfigurable intelligent surface(RIS)technology.Second,due to the broadcast characteristics of channels in full-duplex(FD)NOMA vehicular cooperative communication network,vehicular communication security is difficult to be effectively guaranteed and network interruption is easy to be caused.A NOMA-FD optimal relay selection scheme is proposed to decrease the secrecy-outage-probability(SOP),which guarantees safe and efficient data transmission for legitimate on-board users by sending noise to the eavesdropping vehicle users through any relay and using residual auto-interference elimination technology for NOMA full-duplex relay.Numerical simulation results also verify the theoretical results.It is worth noting that the proposed scheme can enormously reduce the SOP of the system and effectively improve the security performance of the communication system while ensuring a lower complexity of the system by setting reasonable parameter.Third,increasing the demand of vehicular communication networks slows down the information transmission of vehicular network.In addition,the fixed unmanned aerial vehicle(UAV)relay has limitation on the location.An alternate optimized iterative algorithm is proposed to optimize UAV relay trajectory and thus improving the efficiency of vehicle transmission information.The non-convex optimization problem obtained by the trajectory design with the maximum average transmission rate,the algorithm not only discretizes the whole communication process but also adopts the method of sequential convex programming to solve the non-convex problem by introducing relaxation variables,and thus calculating the flight trajectory of the UAV with the maximum transmission rate.Moreover,in order to ensure the safety of the communication system,the relay scheme of UAV-assisted RIS technology is also adopted.Numerical simulation results shows that,the optimal average transmission rate can be obtained by optimizing the trajectory of UAV and the system SOP is reduced with the assistance of RIS technology,which can effectively improve the transmission rate of the communication system and ensure the safety performance.