【作者】 张静；

【导师】 步兵；

【作者基本信息】 北京交通大学 ， 交通信息工程与控制， 2010， 硕士

【摘要】 车-地无线通信作为CBTC的重要环节,在很大程度上影响着整个运行控制系统的性能,一直以来都是研究的热点之一。在大量查阅国内外CBTC车地通信系统研究现状的基础上,笔者发现其中关于大铁GSM-R的研究稍多,城轨WLAN无线局域网方面的却较少,且缺少列控、通信相结合的研究。因此,本文在阐述城轨CBTC中车地无线信道特点的基础上,对影响列控系统的主要车地通信性能指标以及列车运行控制对车地通信系统的要求进行分析,并对CBTC系统主要通信参数进行了合理设计,论文在这方面的研究有一定的现实意义。论文根据CBTC中车地无线信道的特点,分析了影响列控系统运行的主要车地通信性能指标,包括：传输错误信息、区间运行出现的连续丢包以及越区切换中断时间；就列车运行控制对车地通信的要求,对列车区间追踪运行对通信中断时间要求进行了分析,并提出了一个合理的系统通信中断时间门限值。论文对CBTC中主要的无线通信参数进行了设计：结合仿真和实测结果,对隧道内无线传播损耗模型进行了修正,并综合阴影衰落、小尺度衰落其他影响通信距离的参数,对城轨CBTC系统区间AP布设进行了设计；利用分析衰落信道的经典GE模型,对区间连续丢包进行了统计分析,指出影响连续丢包个数的主要原因是信号的电平通过率以及平均衰落持续时间；最后分析了越区切换的整个流程,以及影响越区切换时间的主要因素,基于实测统计给出了不同情况下越区切换的时间。论文最后利用OPNET仿真平台,建立了完整的基于802.11g的CBTC车地通信系统仿真模型；利用该仿真平台仿真了列控业务下的通信系统性能,并将之前分析所得参数结果引入具体的列控模型,分析了通信对列车追踪运行的影响。更多还原

【Abstract】 To a large extent, wireless communication affects the performance of the train control system of CBTC. Up to now, there are more studies on GSM-R of railway than those on WLAN (Wireless Local Area Network) of mass transit. In addition, there is no such study about the relationship between train control accuracy and train ground communication performance. For this reason, this thesis analyses the major performance of train ground communication, which influence the train control system. Firstly, the requirements of CBTC on wireless communication are analysed. Secondly, some parameters of the wireless communication system of CBTC are analysed. Furthermore, the major communication parameters in CBTC is designed based on the CBTC requirement. To some extent, these studies may be used for practice.Based on the characteristics of the wireless channel in CBTC, Qos of communication is analyzed. The performance metrics includes:transmission error, continuous packet loss, and interruption time of handoff. The interruption time requirement of CBTC on the interruption time is also analysed. A rational threshold of the interruption time is given.The major parameters of train ground communication system in CBTC is designed in this thesis. The wireless propagation loss model in tunnels is refined based on the simulation results and field measurements. Combined with other many other factors, a suitable interval between AP is suggested. Through GE model, the statistic of continuous packet loss is analyzed, and point out that the main reason that influence the number of continuous packet loss is level passing rate and average duration of fading. The whole process of handoff and the major factors influencing the handoff time is analyzed in the thesis. The handoff time in different circumstances is obtained from field measurements.Using the OPNET simulation tools, the thesis construct a whole train ground communication system simulation model in CBTC based on 802.11g. Based on this model, the thesis simulates the performance of the train-ground communication system under the train control trafic. It also analyze the train ground communication’s effect on train tracing operation with the simulation model and the relative parameters derived before.更多还原