Research On The Application Of V2X Key Technology In Intelligent Transportation For Urban Road

With the rapid development of urbanization in China,traffic demand is increasing so rapidly that serious social problems have been caused by traffic congestion and accidents.Intelligent Transportation System(ITS)is the best way to solve the problem of urban traffic congestion,improve the efficiency of operation and the urban environment quality,ensure the safety of driving.The foundation of ITS lies in the device interconnection and information exchange.V2X(Vehicle to Everything)as an in-depth research on the D2D(Device to Device)technology,realizes information sharing between vehicles and traffic infrastructure based on D2 D technology,which becomes a research hotspot in ITS.On the basis of summarizing the present situation of technology research and application at home and abroad,the key technology of LTE-V2X(Long Term Evolution-Vehicle to Everything)based on D2 D is studied.In order to solve the problem of destroying the orthogonality of the original internal resources due to the reuse of cell network resource under the LTE-V implementation scheme,the key technology such as Interference control and resource allocation is researched deeply.In order to solve the problem of increasing traffic flow,the interference control under high density is studied.A mathematical method of game theory is introduced.Firstly,the rate calculation of each V2 X user under the resource reuse implementation scheme is converted into the revenue function,and then a rational power control scheme is made by analyzing what other V2 X may do based on the environmental strategy in the game.The simulation experiments show that under the effective constraint of the optimal response strategy,the user can sensibly choose the transmission power,and under the guarantee of the speed and accuracy of the information transmission,the sub-optimal rate performance is obtained by using the appropriate energy expenditure,thus making the V2 X system have better interference control and energy efficiency benefits,and accommodate more V2 X users in a single cell.Therefore,high density transmission between vehicles and infrastructure or between vehicles and vehicles in the road are carried out.In terms of transfer resource allocation implementation of V2 X users,existing research is carried out basically around the goal of optimal throughput performance of single cells.However,optimal system performance does not mean the throughput of each V2 X is optimal,which would create an unfair phenomenon of resources distribution,In order to solve the problem,two aspects is mainly studied as follows:To meet different service requirements for large number of vehicles and traffic accidents in road areas.the first way is to allow a V2 X user to reuse multiple cellular user resources in the application scheme by establishing a one-to-many resource allocation model so as to improve throughput performance gains.In order to meet the different needs of D2 D users for radio resource,the heuristic resource reuse allocation algorithm based on weights of rewards and punishments is designed,thus the quality of service for the different users can be guaranteed.It is shown that the V2 X resource multiplexing allocation algorithm under the weighting mechanism can satisfy quality of service of several users through the adaptive adjustment of the parameters of reward and punishment at the expense of a small amount of system performance,so the algorithm is in relatively fair resource allocation state.Therefore,the demands of different service quality such as the low latency and interaction information of traffic events are satisfied.Secondly,to solve the problem of the mutual explosion of information on urban road traffic,,the graph theory is studied to describe the distribution relationship between V2 X users and cellular network resources.Then a distributed iterative algorithm is proposed to solve the problem of performance bottleneck and incomplete information due to centralized calculation of cellular base stations.In the algorithm,the V2 X user autonomously selects the cellular RB resources according to the dynamic interference environment of the cellular network resource,and the base station selects the optimal V2 X user allocation resource according to the throughput rate gain,thereby collision problem of multiple users for the same cell is avoided.The simulation experiment shows that the bipartite graph algorithm has better throughput and lower computing complexity.Through the distributed collaboration and competition of the resource for each V2 X use,the information interactive throughput of each vehicle in the road area is improved.