Reliability Analysis And Research Of Wireless Communication System Based On LTE-R

The railway system is an extremely complicated and large system.Any subsystems,facilities,equipment,weather changes,human factors,etc.in the system may affect the railway system.If the treatment at the prevention and control stage is unreasonable,the quality and safety of the railway operation will be affected.The impact will endanger the safety of train operation,even in extreme cases,the consequences are unimaginable.The communication system in the railway subsystem serves as the information bearing platform of the railway Internet of Things,and its safety and reliability are directly related to the safe operation of the train.In recent years,due to the rapid development of high-speed railways,the services provided by the existing GSM-R communication system can no longer meet the communication needs.Therefore,the International Railway Union has proposed the LTE-R railway dedicated mobile communication system because of its low latency,high speed,flexible carrier bandwidth,high security and high reliability,etc.,more suitable for high-speed use.The LTE-R wireless communication system is a relatively complicated system.Once the LTE-R network fails,it is likely to cause serious security accidents,and it is necessary to perform reliability analysis on its system.Firstly,the thesis introduces the system characteristics,system services,system network structure,wireless access network coverage and core network redundancy of the LTE-R wireless communication system,and uses the system RAMS as the theoretical basis to identify the RAMS that affects the railway system.Factors,it is determined to use the combination of Fault Tree Analysis method and Neural Network method as the reliability evaluation method of LTE-R wireless communication system.In view of the difficulty in selecting smooth factors of traditional Generalized Regression Neural Network,this paper proposes to use the fruit fly algorithm in swarm intelligence algorithm to optimize the smooth factors of GRNN Neural Networks and establish FOA-GRNN model.Secondly,the thesis takes the Beijing-Shenyang LTE-R test section as the research object,and analyzes the factors related to the reliability of the LTE-R wireless communication system according to the network structure of the Beijing-Shenyang LTE-R test section and the impact of the QoS index on train operation And use the Fault Tree method to establish a Fault Tree model;use Neural Networks to predict the reliability of the entire system based on experimental data,and compare with the prediction results of traditional BP model,GRNN model and improvedFOA-BPNN model The final prediction results and prediction errors indicate that the FOA-GRNN model's prediction is better than the other three models,thus establishing the relationship between the reliability of the LTE-R wireless communication system and the use time.Finally,according to the reasons analyzed,the reliability and security measures of the LTE-R wireless communication system are proposed.The equipment proposes to improve the reliability through the use of dual-machine hot backup technology and cluster technology;The core network proposes to adopt the network Function virtualization cloud technology platform to improve reliability;Terminals propose to use terminal pass-through technology to allow direct communication between trains to improve reliability;E-NodeB proposes to use Radio Remote Unit inter-frequency redundant interleaving groups Network mode to improve reliability;Propose the use of artificial intelligence-based communication system fault intelligent analysis and early warning technology for the entire communication system to improve the reliability of the LTE-R wireless communication system.In this thesis,the method of combining Fault Tree Analysis and FOA-GRNN Neural Network is proposed.According to the reliability historical data of different devices and links,the FOA-GRNN Neural Network method is used to process,thereby establishing the reliability of LTE-R wireless communication system.With the change of the use time,it can help the research and production personnel in the actual engineering to improve the reliability of the LTE-R wireless communication system,and perform timely detection and maintenance of the LTE-R communication system.