Research On Interference Wireless Communication System Suffered In High-speed Train

In recent years,with the railway speeding and a series of high-speed railway to be built, Chinese railway industry develop rapidly. To meet the technical requirements of mobile communication system in high-speed railway, the International Union of Railways (UIC) put forward the concept of LTE-R (LTE for railways) during the study of LTE/SAE, the railway department also expect to achieve the signals covering widely in a cost-effective way. Existing standards are not fully applicable to LTE-R system, based on this case, it is necessary to study the disturbance source which may affect LTE-R system to work in high-speed rail environment, judge all kinds of disturbance’s impact on LTE-R system on the train, analyze anti-electromagnetic interference characteristics of LTE-R system.This paper studies how wireless vehicle communication system is affected by disturbance produced by electric railway when it is applied to the high-speed railway, and corresponding anti-electromagnetic interference, take a new generation of railway broadband mobile communications technology LTE-R as an example, analyse how railway radio noise interfere it. Firstly it introduces the evolution of the existing railway radio communication system to the next generation of railway communication systems LTE-R. Secondly it analyzes electromagnetic environment which LTE-R high-speed rail vehicle system is in, based on basics of three electromagnetic compatibility elements, and introduces our EMC standard railway GB/T24338-2009"Rail EMC." Then it introduces a very important disturbance source-noise when pantograph is off line in electric railway. Finally, through high-speed railway field tests, we collect a large number of pantograph offline disturbance signal, use simulation software to process these data and make intuitive characteristic diagram of time domain and frequency domain, the results show, radiant energy generated by pantograph offline signal mainly distribute in the frequency range from300MHz to1GHz, the radiation field energy generated by pantograph offline signal is very small in the frequency range of1.88GHz～2.6GHz which LTE-R vehicle system of high-speed rail work in, it is not enough to affect the LTE-R signal device. On the other hand, the impact on its normal work which the radiation field generates is very weak through LTE-R signal device’s slit, the impact on the antenna is also small, but we still need to combine specific equipment for further study. End of the article also analyses the device its own resistance to electromagnetic interference, which is based on LTE-R system characteristics, we consider comprehensively from three EMC factors (the disturbance source, coupling path and sensitive equipment), and provide the corresponding interference suppression measures.