高铁无线通信融合架构下的无线探测技术

发布时间：2017-12-27 11:28

本文关键词：高铁无线通信融合架构下的无线探测技术　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：高铁的不断提速对运行安全提出了更高的需求,尤其是对铁路沿线环境的滑坡、泥石流和异物入侵等监测和安全预警备受关注。相关的铁路监测方法随之产生,如基于GPS(Global Positioning System)的定位监测、无线传感器监测、视频监测等,但这些监测设备易被破坏,且工作性能受到光线、天气等制约。相比之下,毫米波探测有不受光线和自然灾害的影响、可全天候工作的优点。不仅如此,毫米波探测设备简单,而且分辨率较高。另一方面,未来5G无线通信(Fifth-generation Wireless Communication)需要将容量提高 1000 倍才能满足无线业务需求,而毫米波频段频谱资源丰富,毫米波通信势必会成为未来无线通信的趋势。因此,借助未来无线通信的发展趋势以及毫米波探测技术的优势,有必要将上述两种技术集成于一个系统中,使得该融合系统兼具无线传输及灾害监测与预警功能。本文的研究均基于高铁无线通信和探测融合架构。首先,根据实际铁路场景中无线监测和无线通信需求对融合架构进行了设计,为减少小区间的切换次数,系统网络采用云接入架构,BBU(Building Baseband Unit)负责数据处理和资源分配,RRU(Radio Remote Unit)只有收发模块。RRU分为毫米波频段RRU和专网/公网低频授权频段RRU,毫米波频段RRU分时地负责大容量通信和毫米波探测,专网/公网低频授权频段RRU负责低容量可靠数据(环境探测信息和重要信令)的传输。由于本系统中的毫米波频段RRU分时进行通信和探测,列车一旦和源小区中RRU断开连接,则无法连回。基于此,本文提出一种"双保险"的方法,仿真结果表明,本文所提切换方法相比于传统的LTE-R(Long Term Evolution for Railways)硬切换,在切换成功率和链路中断概率上有明显的改进。对于系统探测功能来说,雷达目标检测算法的好坏直接影响系统性能。针对高铁复杂多变的探测环境,本文提出了一种二维VIS-CFAR(Switching Variable Index Constant False Alarm Algorithm)算法,该算法能够根据周边环境,自适应选择相应的目标检测算法,大大降低了系统漏警率。最后,本文仿真了三种不同场景,将本文所提二维VIS-CFAR算法和多种经典恒虚警算法在均匀杂波环境、杂波边缘环境、多目标干扰环境的检测性能进行了对比,结果表明,本文所提二维VIS-CFAR算法高铁场景下具有稳定的性能,可大大提高融合系统的检测效率。
[Abstract]:The increasing speed of high-speed railway has put forward higher demand for operation safety, especially for monitoring and safety warning of landslide along the railway line, debris flow and foreign matter intrusion. Related railway monitoring methods are generated, such as location monitoring, wireless sensor monitoring, video surveillance based on GPS (Global Positioning System), but these monitoring devices are easily destroyed, and their performance is restricted by light and weather. In contrast, millimeter wave detection has the advantages of not affected by light and natural disasters, and can work around the weather all over the world. Not only that, the millimeter wave detection equipment is simple, and the resolution is high. On the other hand, 5G Fifth-generation Wireless Communication needs to increase capacity by 1000 times to meet the needs of wireless business. Millimeter wave band spectrum resources are abundant, and millimeter wave communication is bound to become the trend of future wireless communications. Therefore, with the development trend of the future wireless communication and the advantages of millimeter wave detection technology, it is necessary to integrate the above two technologies into a system, so that the fusion system has the functions of wireless transmission, disaster monitoring and early warning. The research in this paper is based on the architecture of high speed wireless communication and detection fusion. First of all, according to the actual demand of wireless communication and wireless monitoring of railway scene on the fusion of architecture design, in order to reduce the switching frequency of each cell, the system uses cloud access network architecture, BBU (Building Baseband Unit) is responsible for data processing and resource allocation, RRU (Radio Remote Unit) only transceiver module. RRU is divided into millimeter wave band RRU and private network / public network low frequency authorized frequency RRU. Millimeter wave band RRU is responsible for large capacity communication and millimeter wave detection. Private network / public network low frequency authorized frequency RRU is responsible for the transmission of low capacity reliable data (environmental detection information and important signaling). Due to the communication and detection of the millimeter wave band RRU in this system, the train can not be connected once it is disconnected from the RRU in the source area. Based on this, this paper proposes a "double insurance" method. Simulation results show that the proposed handoff method has a significant improvement in handover success rate and link outage probability compared with the traditional LTE-R (Long Term Evolution for Railways) hard handoff. For the system detection function, the radar target detection algorithm directly affects the performance of the system. Aiming at the complicated and changeable detection environment of high-speed railway, a two-dimensional VIS-CFAR (Switching Variable Index Constant False Alarm Algorithm) algorithm is proposed in this paper, which can adaptively select corresponding target detection algorithm according to the surrounding environment, which greatly reduces the miss rate of the system. Finally, three different scenarios, the simulation will be the two-dimensional VIS-CFAR algorithm and several classical CFAR algorithm in homogeneous clutter, clutter edge environment, the detection performance of multi target interference environments were compared. The results show that the proposed 2D VIS-CFAR performance for HSR scenarios with stable, can greatly improve the detection efficiency of the fusion system.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN92;TN957.51

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