Research On Radio Resource Allocation Algorithm For LTE D2D Based V2V Communication

With the congested urban roads and traffic accidents increasing,it has created an increased demand for intelligent transportation and smarter cities.Against this kind of background,this dissertation will carry out research on this communication problem between vehicles and vehicles(V2V).The MAC protocol currently used in VANET is mainly based on IEEE802.11 p protocol.Although the IEEE802.11 p protocol is in line with the requirements of intelligent transportation system,it also has some shortcomings,such as low scalability,poor communication reliability and its delay is not controllable and so on.Through analysis and validation,some scholars have proposed a method based on D2 D communication mode introduced in LTE cellular network to design the vehicular communication networks.However,due to the reuse of radio resources,it will inevitably introduce communication interference,and how to suppress the interference between V2V communication and cellular communication,there are two very important aspects should be considered carefully.One is the problem of radio resources allocation,and the other is the problem of power control.The existing research model is mainly established on static communication scenarios,and the dynamic property of user terminals is seldom considered.However,in the communication scenarios to be studied in this dissertation,the V2V communication request will be a dynamic process.Nevertheless,the existing resource allocation algorithms and power control mechanisms cannot be applied to this kind of scenario.In order to improve the utilization of communication resource s as much as possible,in the third chapter of this dissertation,the traffic flow states on the road are simply modeled,which are divided into three different states: saturated traffic flow,unsaturated traffic flow and sparse traffic flow.Due to the la rge number of vehicles on the road to apply for V2V communication,and the available radio resources of LTE cellular system are very limited.So that,in order to make more V2V links access to radio resources,we will carry out the research on V2V communication resources allocation algorithm in the third chapter.And then we have designed a traffic flow characteristics based on dynamic resource allocation algorithm.Finally,through the comparison of the experimental simulation,we can conclude that the proposed resource allocation algorithm is superior to the greedy algorithm and the random allocation algorithm remarkably in the running time and spectral efficiency aspects.And these two performance indexes are particularly important for the volatile communication environment of V2V links and the status of spectrum scarcity.In the process of V2V links' radio resource allocation,it assumes that the V2V transmit power is determined in advance,and there is no consideration for their power control problems.In this stage,it is mainly to allocate corresponding radio resources to the V2V communication links,and then to realize the information interaction between vehicles and vehicles(V2V).Therefore,based on the research of Chapter 3,the power control problem of V2V communication will be studied in the fourth chapter,and a new power control algorithm is given.Finally,through the simulation experiments,we can conclude that smaller communication interference is introduced by the designed power control algorithm compared to the fixed power control strategy.In addition,under this new power control mechanism,the V2V links can obtain higher communication capacity and power utility value.