Research On Transmission Security And Reliability Of D2D Communication In Internet Of Vehicles

With the development of wireless communication and digital intelligent vehicle technology,vehicles are developing in the direction of networked and intelligent connected and autonomous vehicles(CAVs).Based on mobile data communication and equipped with advanced vehicle sensors and intelligent control equipment,CAVs can realize portable and reliable data interchange between vehicles to vehicles(V2V),vehicles to infrastructure,vehicles to pedestrians,and vehicles to cloud in the internet of vehicles(Io Vs)environment.It has become the basic condition for ensuring driving safety,improving traffic efficiency and providing driving services.Therefore,exploring the Io V-based data transmission technology is of great significance to promote the development of CAVs.Device-to-device(D2D)communication technology,as one of the primary techniques in V2 V,enables the vehicle to communicate directly for reducing the transmission delay and the load of the Io V base station.Therefore,it can effectively enhance the transmission performance of the Io Vs while ensuring the quality of communication transmission.By introducing technologies such as simultaneous wireless information and power transfer(SWIPT),cooperative transmission,physical layer security and orthogonal frequency division multiplexing into D2 D communication to meet the requirements in different Io V scenarios,it can improve the security and reliability of the Io V communication.The main work of this paper is as follows:(1)Considering that the Io V environment with eavesdropping or interference,this paper focuses on the D2 D communication under the overlay mode,which improves the network security performance by adopting relay cooperation and physical layer security technology.Firstly,this paper proposes an adaptive time allocation relay scheme for one-way Io V model under eavesdropping,and analyzes the system security performance via time-varying channel in present of channel estimation error;secondly,for the two-way Io V with eavesdropping,this paper adopts SWIPT-based relay scheme to improve energy utilization for prolonging network lifetime.Furthermore,an adaptive hybrid power splitting(PS)and time allocation(TA)strategy is introduced to further optimize energy efficiency;finally,for the Io V model under the interference,this paper proposes a D2 D and visible light communication(VLC)combined data transmission scheme.The interfered vehicles can receive the information via the RF or VLC link through the relay vehicle,which,in turn,will reduce the impact of interference.(2)In view of the shortage of spectrum resources faced by the Io V,this paper studies the D2 D communication in the underlay mode and proposes a cognitive Io V model to realize the D2 D two-way communication.In this model,the vehicle can not only be used as a relay to assist cellular users for data transmition to improve communication reliability,but also can use the corresponding base station spectrum resources for V2 V communication to meet the requirements of the Io V.In addition,according to the SWIPT-based relay technology,this paper analyzes the network under different relay modes and channel models by using a hybrid PS and TA energy harvesting scheme.Then,the network performance is evaluated by deriving the exact expressions of outage performance and throughput,and the system parameter values under the optimal performance are given.Finally,the simulation verifies the correctness and effectiveness of the strategy used in the proposed network model.(3)As for the distortion caused by the high peak to average power ratio(PAPR)of the Io V transmitted signal through the power amplifier(PA),multi-objective optimization based selected mapping and immune-based tone injection schemes are proposed.Through multiobjective fitness optimization,angle increment update and feature information processing,signal distortion in these two schemes can be effectively reduced.Simulation results show that the two schemes can significantly improve the Io V performance.By analyzing the limitations of typical indexes(bit error rate and complementary cumulative distribution function of PAPR)in distortion technology,bit error rate of different power consumption under given PA and channel noises level is introduced to further evaluate the impact of signal distortion on the the Io V system performance.The effectiveness of the index is finally verified by simulation.