Research On Resource Scheduling Algorithm Based On Multi Services In High-speed Railway Environment

The rapid development of high speed railway has brought great convenience to people's life.How to ensure high quality communication service in the fast moving environment has become a hot spot of research.As a new generation of railway communication system,LTE-R can effectively meet the growing demand of users,but the scarcity of wireless spectrum resources still exists.Especially in the case of multi business coexistence,the diversity of business types increases the difficulty of making more rational use of spectrum resources.Therefore,based on cross layer packet scheduling scheme,an improved multi service resource scheduling algorithm is proposed,and the algorithm is verified.The simulation results show that the improved algorithm can effectively reduce the packet transmission delay and improve the frequency band utilization of the system compared to the traditional multi service scheduling algorithm.The main contents of the paper are as follows:(1)The LTE-R system is analyzed,including three aspects,including the architecture,the key technology and the resource structure.The architecture includes access network,core network and protocol stack.The key technologies include multi carrier modulation technology,multi antenna technology and link adaptive technology.The resource structure includes frame structure,resource block and resource allocation mode.(2)The strategy and business analysis of resource scheduling are introduced.Firstly,the content of the concept of packet scheduling,the operation steps of packet scheduler,and the model architecture are expounded.In addition,the 4 most common resource scheduling algorithms are analyzed: polling algorithm,maximum load stem ratio algorithm,positive proportional fair algorithm and improved maximum time delay priority algorithm,and the four algorithms are compared.Point.Then the representative real-time service is analyzed,and the voice group call and voice broadcast are selected in the column control service.The passenger service selects the packet voice and the network TV to analyze its characteristics.At last,the characteristics of non real time service are analyzed.The train control service selects the dispatch command information,train number information and column tail wind pressure information.The passenger service selects text files and e-mail,and analyzes their characteristics.(3)The multi service resource scheduling algorithm is introduced.First,the traditional multi service resource scheduling algorithm is introduced,which provides a contrast basis for the next analysis.Then,on the basis of the packet cross layer scheduling scheme,the priority of the real time service and non real time service is improved,and the factors representing different types of business are introduced to the priority decision.(4)Selecting the representative line control service and passenger service,carry on the simulation analysis to the improved multi service resource scheduling algorithm.By changing the train speed,the improved algorithm is evaluated and analyzed.According to the simulation results,the improved scheduling algorithm can effectively reduce the packet delay when the train speed is different.The band utilization of high system can better adapt to the high speed environment.