Design Of Resource Allocation Mechanism Based On The Service Requirement In LTE-V2V

Vehicle-to-Vehicle(V2V)communication is considered to be the key technology to realize intelligent transportation system,which can improve traffic safety and traffic efficiency,reduce energy consumption and support new services in the intelligent transportation system,etc.However,comparing with the traditional communication,V2 V communication has stricter performance requirements on reliability and latency.Therefore,different communication standardization organizations proposed their own protocol standards of system architecture in Internet of Vehicles.Among them,the 3rd Generation Partnership Project(3GPP)proposed that V2 V technology can be realized by modifying D2D(Device-to-Device)technology standardized in LTE-A.The modified aspects include V2 V resource pool design and resource allocation mechanism,etc.Regarding the resource allocation mechanism in V2 V,this thesis focuses on the resource collision when VehicleUser Equipment(V-UE)selects the resources in resource pool without base station scheduling.Then,it proposes the solution schemes and the simulation verification.In this thesis,the main research and innovation are as following:1.LTE-V2 V resource selection algorithm based on the resource pool: First,it is analyzed that V-UE selects the resources in resource pool based on both non pre-configured and pre-configured strategies,established a resource collision probability model and summarized a pre-configured resource selection algorithm based on the number of occupied,which can adjust the selection probability of different resources in order to reduce resource collision probability.Then,according to the different reliability requirements of different LTE-V2 V services,a resource selection algorithm based on resource segmentation is proposed,which can segment the resource pool according to the volume and priority of services and make the different services select the resources that meet their own reliability requirement.Through the simulation,this algorithm can improve the reliability of higher priority service.2.LTE-V2 V Resource pool channel detection mechanism: By introducing the Listen Before Talk(LBT)mechanism,combined with the characteristic of LTE-V2 V channel resources,a new channel detection mechanism suitable for LTE-V2 V is given.This mechanism can realize the collision avoidance by detecting the conflicts and retreating;Meanwhile,it discusses two different contention windows setting of LBT algorithm and compare the influence of the probability of channel occupancy.From the theory and simulation,it is proved that the detection number of idle times is more suitable to be the contention window for the LTE-V2 V resource pool channel detection mechanism.The mechanism can improve the package receiving rate of the system and reduce the influence of the average delay of higher delay priority service.