Train-to-train(T2T)communication can provide protection for existing train-to-ground private network communication,and its channel characteristics directly affect the application of upper-layer communication technolog...Train-to-train(T2T)communication can provide protection for existing train-to-ground private network communication,and its channel characteristics directly affect the application of upper-layer communication technologies.In this study,based on the spatial distribution structure of railway operation scenarios and Fresnel zone theory,we propose a frequency allocation scheme for direct communication between tracking trains in flatland and long straight tunnel scenario.Then we use the estimation method of radio wave attenuation caused by rainfall to analyze the large-scale path loss fading of multi-band wireless channels.Furthermore,we derive the calculation equation of max Doppler frequency shift suitable for T2T communication and describe the multipath wave in the tunnel by ray tracing method to analyze small-scale fading.Simulation analysis shows that the Doppler shift value of T2T communication low frequency band is significantly lower than the frequency shift value of the train-to-ground communication under the same speed conditions.展开更多
This paper explores in depth the development history,current status,challenges,and future trends of wireless communication systems for train-to-ground and train-to-train in urban rail transit.The train-to-ground commu...This paper explores in depth the development history,current status,challenges,and future trends of wireless communication systems for train-to-ground and train-to-train in urban rail transit.The train-to-ground communication system enables real-time data transmission between trains and the control center through the collaboration of onboard and ground devices,ensuring safe train operation;the train-to-train communication system focuses on direct information exchange between trains,optimizing operational efficiency.Communication systems have evolved from early dedicated channels,analog clusters,to modern WLAN,LTE-M,and the introduction of 5G technology,continuously upgrading to meet the growing operational demands.However,issues such as limited spectrum resources,multi-mode compatibility,anti-jamming capability,system reliability,network security,and construction and maintenance costs remain to be addressed.In the future,the deeper application of 5G technology,multi-mode integration,intelligent operation and maintenance,network slicing,and the integration of cloud platforms and big data technologies will drive the system toward greater efficiency and intelligence,providing strong support for the modernization of rail transit.展开更多
As the latest research direction of train-to-train communication,virtual coupling train formation technology has attracted the attention of many scholars.This paper studies the influence of time delay on the formation...As the latest research direction of train-to-train communication,virtual coupling train formation technology has attracted the attention of many scholars.This paper studies the influence of time delay on the formation of virtual coupled trains.We proposed a distributed PID controller,which means that trains can still form a stable fleet operation under the influence of communication delay and control delay.After modelling and analysis,the research uses Matlab to conduct simulation,involving two sets of experiments.Factors including speed,acceleration,position,position error,expected distance between adjacent trains and actual distance between adjacent trains are simulated.The results demonstrate that the distributed PID controller can effectively control the impact of time delay on the virtual coupling fleet.展开更多
基金National Natural Science Foundation of China(No.61763023)Lanzhou Jiaotong University-Tianjin University Innovation Fund(No.20180519)。
文摘Train-to-train(T2T)communication can provide protection for existing train-to-ground private network communication,and its channel characteristics directly affect the application of upper-layer communication technologies.In this study,based on the spatial distribution structure of railway operation scenarios and Fresnel zone theory,we propose a frequency allocation scheme for direct communication between tracking trains in flatland and long straight tunnel scenario.Then we use the estimation method of radio wave attenuation caused by rainfall to analyze the large-scale path loss fading of multi-band wireless channels.Furthermore,we derive the calculation equation of max Doppler frequency shift suitable for T2T communication and describe the multipath wave in the tunnel by ray tracing method to analyze small-scale fading.Simulation analysis shows that the Doppler shift value of T2T communication low frequency band is significantly lower than the frequency shift value of the train-to-ground communication under the same speed conditions.
文摘This paper explores in depth the development history,current status,challenges,and future trends of wireless communication systems for train-to-ground and train-to-train in urban rail transit.The train-to-ground communication system enables real-time data transmission between trains and the control center through the collaboration of onboard and ground devices,ensuring safe train operation;the train-to-train communication system focuses on direct information exchange between trains,optimizing operational efficiency.Communication systems have evolved from early dedicated channels,analog clusters,to modern WLAN,LTE-M,and the introduction of 5G technology,continuously upgrading to meet the growing operational demands.However,issues such as limited spectrum resources,multi-mode compatibility,anti-jamming capability,system reliability,network security,and construction and maintenance costs remain to be addressed.In the future,the deeper application of 5G technology,multi-mode integration,intelligent operation and maintenance,network slicing,and the integration of cloud platforms and big data technologies will drive the system toward greater efficiency and intelligence,providing strong support for the modernization of rail transit.
文摘As the latest research direction of train-to-train communication,virtual coupling train formation technology has attracted the attention of many scholars.This paper studies the influence of time delay on the formation of virtual coupled trains.We proposed a distributed PID controller,which means that trains can still form a stable fleet operation under the influence of communication delay and control delay.After modelling and analysis,the research uses Matlab to conduct simulation,involving two sets of experiments.Factors including speed,acceleration,position,position error,expected distance between adjacent trains and actual distance between adjacent trains are simulated.The results demonstrate that the distributed PID controller can effectively control the impact of time delay on the virtual coupling fleet.
