【摘要】 研究目的:目前,中、长铁路隧道主要采用漏泄同轴电缆(漏缆)作为载体进行无线信号覆盖。本文针对现有GSM-R漏缆挂设高度对线缆维护和检修的不便,建立隧道环境下的漏缆信号覆盖模型并进行仿真计算,分析隧道中漏缆挂设高度对无线信号覆盖效果的影响;并通过不同场景下的信号覆盖测试验证仿真计算的正确性,确定合适的漏缆挂设高度。研究结论:(1)在双线隧道中,当机车天线位于同侧靠近或异侧远离漏缆时,随着漏缆挂设高度降低,等效耦合损耗逐渐增大,但异侧变化幅度相较于同侧情况小;(2)综合考虑隧道内通信质量和漏缆维护两方面,对于非列控需求线路,可以将漏缆挂设高度降低至2. 5 m;(3)对于列控线路,将漏缆挂设高度降低至2. 5 m应谨慎;(4)增大设备发射功率或减小直放站间距能够弥补降低漏缆挂高后对信号覆盖的影响;(5)本研究成果可为相关铁路规范修编和工程设计提供参考。更多还原

【Abstract】 Research purposes: The leaky coaxial cable( LCX) is used as the main carrier for signal coverage of medium and long railway tunnels. Considering the inconvenience to maintenance and inspection due to the existing GSM-R LCX hanging height in the tunnel,a model of LCX signal coverage under the tunnel environment was proposed and theoretical simulation and calculation are performed in this paper,the influence of signal coverage at different LCX hanging heights was analyzed. And the correctness of simulation was verified by signal coverage test under different scenarios,and the appropriate hanging height of LCX was determined.Research conclusions:( 1) In the double-line tunnel,the equivalent coupling loss increases gradually with lowering the hanging height of LCX when the locomotive antenna is located on the same side near LCX or on the opposite side far from LCX,but the variation amplitude of the opposite side is smaller than that of the same side.( 2) Considering both communication quality and maintenance of LCX,the hanging height of LCX can be reduced to 2. 5 m for those railway lines without train control data bearing by GSM-R network.( 3) For those railway lines with train control data bearing by GSM-R network,lowing the hanging height of LCX to 2. 5 m should be cautious.( 4) Increasing the transmitting power or reducing the distance between optical repeaters can compensate the effect of lowering the hanging height on signal coverage.( 5) The research result can provide reference for revision of the related railway design code and design work.更多还原