节点文献
GSM-R高速运行环境下通信分析
GSM-R Communication Analysis under High-speed Movement Enviroment
【作者】 吴砥柱;
【导师】 金心宇;
【作者基本信息】 浙江大学 , 电路与系统, 2010, 硕士
【摘要】 随着高速铁路的快速发展,基于GSM-R网络的CTCS3系统将逐步开始使用,由于国内的测试标准和建设标准还不够完善,为了评估所建GSM-R网络设施和网络性能是否满足高速运动下CTCS3语音业务运行要求,特别是多普勒频偏对于网络性能的影响,为GSM-R网络语音业务性能测试和网络建设提供一定的参考依据,本文结合国内外GSM-R语音业务测试指标评估要求,研究高速运动下多普勒频偏与接收电平、接收质量之间的关系,建立仿真模型预测高速运动下接收电平、误码率的演变规律。从GSM-R系统CSD语音业务要求出发,分析了GSM-R网络体系结构,总结了高速铁路CSD语音业务评估指标的要求;基于高速运动下多普勒频偏的公式,推导出高铁沿线多普勒频偏的仿真计算方法,利用灰色关联度的基本原理,分析了合武线多普勒频偏与接收电平、接收质量之间的关系,仿真结果表明,网络正常运行状态下,接收电平与接收质量相关性很大;分析无线传播多径信道的特点,结合多径衰落条件下高速运动传输误码率分析模型,模拟了速度对误码率的影响,仿真结果表明,速度越高误码率越大;研究了多种电波传播损耗模型,在McGeeHan-Griffiths模型基础上,提出了一种新的修正型MG模型,利用京津线场强实测数据仿真比较,结果表明,修正型MG模型更接近实测数据。
【Abstract】 With rapid development of high-speed railway, CTCS3 system based on GSM-R network would be used progressively, but domestic test standards and construction standards are still not perfect enough. A test is needed to guarantee that the GSM-R network infrastructure and network performance meet requirements of CTCS3 system under the high-speed mobile environment, and to provide a certain reference to GSM-R network voice testing and network construction. This article combines some testing standards and requirements both at home and abroad to study correlation of RxQual, RxLevel, and Doppler Frequency offset under high speed motion and create a simulation model to predict the evolutional trace of SNR and BER under high-speed motion.Beginning with the CSD voice service requirements of GSM-R system, analyzed the GSM-R network architecture and summarized the requirements and test methods of CSD voice evaluation standards of high-speed railway, puts forward the simulation calculation methods of Doppler frequency offset along high-speed railway line on the basis of the formula of the Doppler frequency offset under the high-speed motion, and analyze the relationship of RxQual and RxLevel to the Hefei-Wuhan-line Doppler Frequency offset according to the basic theory of gray correlation, the simulation results show that RxQual and RxLevel have great correlation under the state of normal working network. Through analysis of characteristics of wireless transmission of multi-path channels, the analysis model of high speed transmission BER with multi-path fading conditions is proposed to simulate the effect of speed to BER, and simulation results show that the higher speed cause the higher BER. Four kinds of radio wave propagation loss models were studied, and a new modified MG model based on McGeeHan-Griffiths model was proposed. By stimulation comparison of actual measured data of the Beijing-Tianjin line field, the results show that the modified MG model is more close to actual measured data.
【Key words】 GSM-R; Field strength prediction; Doppler shift; Multi-path fading;