Research On The Wireless Communication Interference To CBTC System In Tunnel Scene

At present, China’s Beijing, Shanghai, Guangzhou, Shenzhen and other cities continue toaccelerate the construction of urban rail transport on the existing foundation, some secondand third tier cities are also actively preparing launched urban rail transit construction. Due toits advanced technology, compatibility, strong transport capacity and other characteristics, theCBTC system has become the first choice around the new line of urban rail transport traincontrol system. However, due to the complexity which is the electromagnetic environmentof urban rail transit tunnel, Some extraneous signals easily cause interference to CBTCsystem, which impact on the normal, safe operation of urban rail transit.This paper, Combining interference test which is conducted on the CBTC system byGuangzhou Metro, studied and summarized the interference test of CBTC system. The paperfirst introduces the principle of moving block，the composition and function of CBTC system,described the CBTC system wireless coverage in three ways, the wireless LAN technologyand it’s wireless channel which is used by CBTC system.Secondly, according to the propagation characteristics of wireless electromagnetic waveand Wireless frequency distribution in tunnel, this paper analyzes the reason of the wirelessinterference on CBTC system. With the aid of the WLAN inter channelinterference factors,this paper also stduies the influence degree of the interference which isefefcted on CBTC system by the PIDS system and portable WIFI.Finally, according to the analysis of wireless interference theory,this paper carries outfield test and analysis, the test and analysi are the portable WIFI devices’s wirelessinterference on the CBTC system of antenna, waveguide and leaky coaxialcable three wireless coverages in tunnel scenario.The paper also compare and analysethe interference effects of transmission performance on the above three kind of wirelesscoverageThis paper only focuses on the analysis and research on the current situation of wirelesselectromagnetic environment in the urban rail transit tunnel, there aremany challenging issues to be studied, such as the interference to the CBTC system after theintroduce of commercial WLAN and TDD LTE’s2.3GHz band signal, and so on.