Simulation And Analyzation The Resource Allocation Algorithm Of LTE Based On Vehicular Network

Vehicular communication network is an important infrastructure of modern intelligent transportation system.Its core functions include V2V(Vehicle to Vehicle),V2I(Vehicle,to Infrastructure)and other communication applications.The earliest technology standard of vehicular networking is IEEE 802.11p which is put forward by the international society of electrical and Electronic Engineers(IEEE),and further developes the technology of vehicular ad hoc networks.Because IEEE 801.11p has not carried on large-scale network deployment and the investment is huge.its application prospect has certain uncertainty.The LTE technology proposed by 3 GPP has been widely used and become the mainstream technology in the world.LTE technology has many advantages,such as wide coverage,high communication speed,low transmission delay and so on.It is necessary to realize the data transmission service needed by vehicular networking.Therefore,the technology of vehicular networking based on LTE has received extensive attention.Due to the LTE technical standards don't consider the requirements of vehicular communication technology,there are still some technical difficulties in vehicular networking technology based on LTE,such as high speed vehicle mobility support,services priority guarantee,reliable transmission of mission critical services,etc.According to the Requirements for reliable transfer of mission critical data for vehicular networking,this paper presents a vehicular safety data transmission scheme based on LTE technology.Combining of service QoS and service priority requirements,the downlink wireless resource management is studied and the system architecture of LTE vehicular network is studied,including access layer,network layer and application layer.The thesis studies two typical communication scenarios.they are the highway communication and the urban dense road.In the communication scene of freeway,the influence of Doppler shift and fast channel change on the reliability and delay of data transmission is considered.In the urban dense road communication scene,the reliable access technology of high density vehicular networking service is mainly considered.In view of the above two typical vehicle communication scenarios,two improved downlink radio resource allocation algorithms are proposed to meet the requirements of QoS and service priority for critical data transmission.(1)Aiming at the communication scene of freeway,an improved algorithm of exponential proportion fairness is proposed.By introducing the optimization parameters of transmission rate,the QoS requirements of real-time services such as vehicular security applications are guaranteed.(2)In view of the tense situation of communication resources in urban road scenes,an exponential proportional fair algorithm based on differentiation function is proposed.the algorithm realizes the hierarchical transmission of different priority services by introducing differentiated functions,so as to ensure the reliable transmission of the critical data of the vehicular network task.In this paper,the above resource allocation algorithms are simulated based on LTE-sim system level simulation platform.Simulation results show that the exponential proportional fairness algorithm based on the transmission rate algorithm can guarantee the reliable data transfer of mission critical data in high speed mobile environment.Simulation results also show the exponential proportional fair algorithm based on differentiation function can meet the requirements of reliable transmission of mission critical data under the condition of guaranteeing system throughput and user fairness in a business intensive urban road environment.