【作者】 李慧；

【导师】 张淑芳；

【作者基本信息】 大连海事大学 ， 信息与通信工程， 2017， 硕士

【摘要】 随着工作在VHF信道的船舶自动识别系统(AIS:Automatic Identification System)开辟了海上数字通信的新纪元,正在研究的海上甚高频数据交换系统(VDES:Very High Frequency Data Exchange System)会将海上数字通信推向另一个制高点。AIS和VDES都工作在VHF(Very High Frequency)频段,为提高VHF信息传输的可靠性,研究各种环境下VHF信号传播特性具有一定创新性和积极的现实意义。基于此,本文研究了跨海大桥对VHF信号传播影响的特征分析,以助于VDES系统的研究与开发。本文首先设计和实现了 VHF信号采集与分析平台,该平台包括硬件系统和软件系统两部分。其中硬件系统由信号发生器、八木定向天线、功率放大器、信号同步设备和USRP(通用软件无线电外设)组成,其中信号同步设备包括PRS10铷原子振荡器和UM220导航/授时模块。软件系统主要包括:基于Windows的Qt开发平台,用于对信号发生器进行参数配置;基于Ubuntu系统的GUN Radio无线电开发平台,用于接收和保存数据。基于上述信号采集和分析平台,本文设计了三种实际测试系统。具体包括:搭建验证平台稳定性实际测试系统、验证定向天线方向性实际测试系统,跨海大桥对VHF信号传播影响海上实际测试系统。其中,前两个实际测试系统均为验证性测试,为实际海上测试奠定基础。基于实际海上测试采集的数据,本文利用MATLAB工具对采集的数据进行处理,基于无线电波的传播损耗理论对数据进行分析。研究成果给出了跨海大桥对VHF信号传播影响与接收端相对于大桥位置的关系,该成果对于沿海VHF信号工作区和跨海大桥的选址设计具有一定的参考价值。本课题是国家自然科学基金重点项目"基于AIS通信系统的船舶无线自动定位新理论与关键技术研究"(61231006)的部分研究内容。更多还原

【Abstract】 A new era of maritime digital communication is opened up by the automatic identification system(AIS:Automatic Identification System)which is working in the VHF channel.The very high frequency data exchange system(VDES:Very High Frequency Data Exchange System)will push sea digital communications to another commanding point,which is in the stage of development.AIS and VDES are all working in the VHF(Very High frequency)band.In order to improve the reliability of VHF information transmission,the study of the propagation characteristics of VHF signals in a variety of environments has a certain innovation and positive practical significance.Based on this,this paper studies the characteristics of the influence of the cross sea bridge on the VHF signal propagation,which is helpful to the research and development of VDES system.Firstly,this paper designs and implements the VHF signal collection and analysis platform for the feature analysis of the influence of cross sea bridge on VHF signal propagation.The platform includes two parts:hardware system and software system.The hardware system is composed of signal generator,power amplifier,Yagi directional antenna,signal synchronization device and USRP(Universal Software Radio Peripheral).The signal synchronization device includes PRS10 rubidium oscillator and UM220 navigation/timing module.The software system mainly includes:Qt development platform based on Windows which is used for the configuration parameters of the signal generator and GNU Radio open-source development platform based on Linux system which is used for receiving data and storing data.Based on the above signal collection and analysis platform this paper designs three kinds of practical test system which are the test system for verifying the stability of the designed platform,the test system for verifying the directionality of antenna and the practical test system at sea.Among them,the first two test systems are the verification test system,which are the basis for the actual test over the sea.Based on the data collected from the practical test at sea,the MATLAB tool is used for the data processing and the theory of radio wave propagation loss is used for data analysis.The results of this paper give the relationship between the influence of the cross sea bridge on VHF signal and the relative location of the bridge to the mobile VHF signal receiver.The contents of this paper is a part of the project of National Natural Science Foundation of China "Research on new theory and key technology of ship wireless automatic positioning based on AIS communication system"(61231006).更多还原