基于ROF技术的高速铁路客车无线接入网络构建研究

发布时间：2018-03-12 12:47

本文选题：无线通信系统　切入点：基站　出处：《兰州交通大学》2016年硕士论文　论文类型：学位论文

【摘要】：高铁无线通信网络,有效地改进了高速移动环境下通话质量下降、容易掉话、数据速率严重下降等通信质量问题,促进了高铁信息化和通信高速化的发展,满足了人们在高速移动环境中对无线通信网络的需求,使无线通信走进了高铁列车,开辟了新的市场。ROF(光载无线通信,radio-over-fiber)技术是无线通信与光纤通信结合的产物,具有无线通信和光纤通信的优势。ROF系统中运用光纤作为基站与中心站之间的传输链路,直接利用光载波来传输射频信号。光纤仅起到传输的作用,交换、控制和信号的再生都集中在中心站,基站仅实现光电转换。把复杂昂贵的设备集中到中心站点,让多个远端基站共享这些设备,减少基站的功耗和成本。高铁通信与传统通信不同之处主要表现在:针对对象、网络结构、建设基站地理环境等。自由空间传播模型是一种理想环境下的通用模型;Okumura-Hata模型适用于频率为150~1000MHz的网络;COST123-Hata模型适用于1500~2000MHz频段、基站高度高于周围建筑物的大/小宏蜂窝环境;KeenanMotley模型适用于室内环境。多普勒效应、频繁的小区切换、严重的车体穿透损耗、高铁沿线特殊环境下建设基站困难等因素都会造成高铁无线接入网络存在弱覆盖区域,甚至盲区。通过对这几种影响因素进行分析研究,提出了使用低频段频率和AFC算法、“移动小区”原理、列车中继天线以及电磁波传播特性这几种关键技术分别解决多普勒效应、频繁的小区切换、严重的车体穿透损耗、高铁沿线特殊路段建设基站困难四种主要困难问题。高铁无线接入网络的构建主要分四个环节完成,第一,规划网络类型,其中包括确定目标和思路、规划频率、规划市区和市区外网络拓扑结构;第二,规划设计基站的站址,其中分基站与基站之间距离的横向规划和基站与铁轨距离的纵向规划;第三,单基站的规划设计,其中包括基站类型的设计、设备的选择以及设备参数的设计;第四,列车上的无线网络设计,其中包括车厢网络的构建原理和组网方式。结合京福高铁铜陵段具体工程,从覆盖目标、经济、技术三个方面进行了可行性分析。根据设计流程规划了京福高铁铜陵段的基站站址,从设备的选择和相应的参数设计两个方面进行了基站设计。通过基站机房和天馈两方面施工,将理论设计与工程施工进行结合。从覆盖率、RSRP(参考信号接收功率,Reference Signal Receiving Power)、SINR(信号与干扰加噪声比,Signal to Interference plus Noise Ratio)以及系统安全性四个方面对工程项目的成果进行了验证。
[Abstract]:The high-speed railway wireless communication network has effectively improved the communication quality problems such as the decline in the quality of the communication in the high-speed mobile environment, easy to drop calls and serious decline in the data rate, and has promoted the development of high-speed rail information and high-speed communication. It satisfies people's demand for wireless communication network in high-speed mobile environment, makes wireless communication enter high-speed train, opens up a new market, radio-over-fibertechnology is the result of the combination of wireless communication and optical fiber communication. In ROF system, optical fiber is used as the transmission link between base station and central station, and optical carrier is directly used to transmit radio frequency signal. Control and signal regeneration are concentrated in the central station, the base station only realizes photoelectric conversion. The complex and expensive equipment is centralized to the central station, so that many remote base stations share these devices. Reducing the power consumption and cost of base station. The difference between high-speed communication and traditional communication is that: for the object, network structure, The free space propagation model is a universal model in ideal environment. The Okumura-Hata model is suitable for the network COST123-Hata model with a frequency of 150 ~ 1000MHz. The Keenan Motley model with the base station height higher than the surrounding building is suitable for indoor environment. Doppler effect, frequent cell switching, severe car body penetration loss, etc. Some factors, such as the difficulty of constructing base station in the special environment along the high-speed railway line, will result in the existence of weak coverage area or even blind area in the high-speed rail wireless access network. Through the analysis and study of these influencing factors, Several key technologies, such as low frequency band frequency and AFC algorithm, "mobile cell" principle, train relay antenna and electromagnetic wave propagation characteristics, are proposed to solve the Doppler effect, frequent cell switching, and severe body penetration loss, respectively. There are four main difficulties in the construction of base stations along special sections of high-speed rail. The construction of high-speed railway wireless access network is mainly divided into four links. First, planning network types, including determining objectives and ideas, planning frequency, Planning the topological structure of the urban area and the network outside the urban area; second, planning and designing the site of the base station, including the horizontal planning of the distance between the base station and the base station and the longitudinal planning of the distance between the base station and the rail; third, the planning and design of the single base station, These include the design of base station type, the selection of equipment and the design of equipment parameters; 4th, the wireless network design on the train, including the construction principle and networking mode of the carriage network, combined with the concrete project of Tongling section of Jingfu high-speed railway, The feasibility analysis is carried out from three aspects of coverage target, economy and technology. According to the design process, the base station site of Tongling section of Beijing-Fu high-speed railway is planned. The base station is designed from the selection of equipment and the corresponding parameter design. Through the construction of the base station computer room and the sky feed, This paper combines the theory design with the engineering construction, and verifies the results of the project from four aspects: the coverage ratio of the reference Signal Receiving (signal to interference plus noise ratio) and the system security.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN929.11;TN92;U285.5

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