铁路数字移动通信系统的传输干扰性能分析与改善

Analysis and Improvement of on Transmission Interference Performance of Railway Digital Mobile Communication System

传输干扰率是铁路数字移动通信系统的服务质量指标中重要的一项,其描述铁路数字移动通信系统误码性能对列车控制信息传输的影响程度。在介绍铁路数字移动通信系统传输干扰基本概念的基础上,分析影响铁路数字移动通信系统传输干扰性能的重要因素,包括列车控制系统信息传输特性、列车控制系统链路层数据传输协议、通信系统越区切换等。基于列车运行速度与传输干扰间的关系,提出采用分布式天线扩大小区覆盖范围的方案,降低数据传输与越区切换发生的碰撞概率,以改善传输干扰性能。通过对分布式天线系统覆盖范围以及对其同频干扰、载波干扰比等性能指标的理论分析,证明了分布式天线覆盖方案可以有效地扩大广义小区的覆盖面积以改善铁路数字移动通信系统传输干扰性能。

Transmission interference is the important one of the quality of service（QoS） of the railway digital mobile communication system indice,which describes the influence of the bit error of the GSM-R system on train control message transmission.The concept of transmission interference of the railway digital mobile communication system is introduced.Then,the factors that influence transmission interference of the railway digital mobile communication system are analyzed,which include the characteristics of train control message transmission,data transmission protocol in the MAC layer and handover of the the communication system.The scheme of the cell coverage area expanded by the distributed antennas system is proposed on the basis of the relationship between the train movement speed and transmission interference performance.This scheme can reduce the collision probability between data transmission and handover improve performance of the co-channel interference and carrier interference ratio.Effectiveness of the proposed scheme is verified by theoretical analysis.