Research On Field Strength Coverage Predicting Of GSM-R In High-speed Railway Environment

Global system for mobile communication for railway(GSM-R), the train operationcontrol system, provides reliable safety assurance for train movement in high-speed railway.To ensure the flatness of rails, many special engineering structures such as viaducts, cuttingsand tunnels are used in high-speed railway. However, the characteristics of radio wavepropagation are closely related to these engineering structure parameters, so the traditionalway that classifies the propagation environments into urban, rural, suburban and open areas isunsuitable.Drawing lessons from existing relative researches on the theory of radio wavepropagation, this thesis proposes a modeling method for large-scale fading and small-scalefading in viaduct and cutting scenarios based on the measure dates of “Zhengzhou-Xian”high-speed railway. In the study about the modeling method in viaduct scenarios, the impactof two structure parameters, relative antenna height and viaduct height, on the characteristicsof radio wave propagation is discussed.In the study about the characteristics of radio wave propagation in cutting scenarios, thisthesis find that the structure parameters, up width, bottom width and depth of the cuttingsignificantly affect the small-and large-scale channel parameters. Research on small-scalefading characteristics shows that channel envelope statistical always follows riceandistribution and ricean K-factor is a function of the structural parameters of engineeringstructure, both in viaduct and cutting scenarios. When the surrounding scatterers are higherthan the height of viaducts, the scatterers have a significant impact on the field strengthcoverage features and the impacts from viaduct structure parameters can be ignored. Incutting scenario, the surrounding obstacles outside the cutting have a marginal impact on thefield strength coverage features, and a “wide” cutting (with both large up width and largebottom width) tends to reduce the severity of fading.Based on the detailed discussion about the relationship between the characteristics ofradio wave propagation and the structural parameters of engineering, a software packageLabWindows-based for field strength prediction in high-speed railway is developed, whichcan provide some valuable reference for GSM-R network planning and designing, as well assome other engineering applications.