Research Of GSM-R System Performance In High-speed Railway Environment

As the digital communication system of China's railway, GSM-R wireless communication system plays a vital role in train communication safety. In order to make sure that GSM-R system can work properly, GSM-R system's performances in different railway environment need to be evaluated. This is always a hot research point in the field of railway communication. Many factors influence GSM-R's performance, tests on railway lines can get the combined effect of different factors, but when it comes to the effects of separate factor to GSM-R system, new research method needs to be brought in. On the other hand, GSM-R system works in various and complex environments, tests on site are limited by many restraints such as expenses and time period, so for improving the situation, a new research way needs to be developed as well.According to the research needs above, this paper introduce the way to imitate railway environment in lab based on hard-in-the-loop simulation, supported by communication system evaluation theory. By analyzing principle of wave propagation and project practice, studies the reason of circuit domain data frame's error in high speed railway environment, the lowest available receive level of GSM-R system and the influences of environment factors to GSM-R system. The main innovation points are shown below:1The way to imitating railway environment in lab is implemented based on hard-in-the-loop simulation. Focusing on the factors that influence GSM-R system performance such as AWGN, coverage level, Doppler frequency shift, a simulation system having4base stations is set up, which can be expended with help of wireless channel simulation platform and GSM-R network equipments.2GSM-R system lowest available receive level in different scenarios is studied, and it is proved that the lowest available receive level is at least lOdB less than the actual GSM-R coverage level. The conclusion is helpful for future GSM-R network planning and optimization.3With the knowledge of factors that influence GSM-R system's performance such as coverage level, mobile speed, interference and small scale model, the features of these factors'effects to GSM-R are studied. And by the in-depth discussion of statistical data processing methods, it is found that the correlation between GSM-R communication quality and coverage level is moderate, the correlation between GSM-R communication quality and mobile speed is strong. Through this paper's research, the combined factors in actual environment that influence GSM-R's performance is separated, the relationships between GSM-R communication quality and factors are fully shown.4Based on the research results, the paper gives a series of suggestion about the network planning and optimization of GSM-R wireless network.