Research On The Radio Coverage Planning Of GSM-R In High-speed Railway Environment

The rapid development of high-speed railway has brought new opportunities to GSM-R,but the high reliability requirements of high-speed railway pose a severe challenge to GSM-R,which serves as the platform for carrying train control information.Wireless access part of GSM-R system is a weak link,so the reliability of the wireless part will determine the overall system reliability.At the same time,fast movement of high-speed trains leads to frequent handover failure,which has a serious impact on the communication,so rational radio planning is needed to ensure the continuity and reliability of the communication.In this papar,focused on the high-speed railway scenario,the pros and cons of the different means of radio redundancy coverage scheme are compared.Cell coverage radius and distance between base stations are planned meeting the requirements of train control.The relationship between train speed and the overlap zone is analyzed with performance simulation.Three types of widely used radio redundancy coverage schemes are thoroughly inspected in terms of system reliability,disaster recovery,frequency utilization efficiency,anti-interference ability and the impact on handover.This comparison provides a theoretical basis for engineering design in the choice of a redundancy scheme.Path loss modeling for several typical environments is done using Hata model in high-speed scenario.Cell coverage radiuses are calculated with different base station antenna height satisfying train control needs.On this basis,the formula for calculating the length of overlap zone is derived,which provides a way to research the impact of train speed,length of handover zone,handover margin and handover time on the overlap zone.Lengths of overlap designed for different maximum speeds are compared with results derived from C/I requirement,proves the former is better in C/I ratio. Finally,the distance between the base stations is planned and compared with the required minimum distance imposed by the error free period(Qos parameter),which leads to the conclusion that small and medium-sized city is not a suitable environment for high-speed trains.