基于白光LED的室内光载FM广播通信系统的研究

发布时间：2018-03-20 05:33

本文选题：可见光通信　切入点：白光LED　出处：《华北电力大学(北京)》2016年硕士论文　论文类型：学位论文

【摘要】：可见光通信(Visible Light Communication,简称VLC)是基于白光LED新兴的一种无线光通信技术。通常分为：室内可见光通信和室外可见光通信。VLC技术有很多优点,它可以解决射频(Radio Frequency, RF)通信快速发展导致的频谱资源短缺问题,还可应用于射频信号不能到达或使用受限的环境中,满足人们特定的通信需求。调频(Frequency Modulation)广播自出世就受到各国的重视和广泛的应用,技术日益成熟。调频广播利用高频电磁波将信号发射出去,覆盖范围广、设备简单,但目前面临一些问题。例如接收容易受到其他设备的电磁干扰、高大建筑物的电磁屏蔽、医院和飞机等环境使用受限等。针对以上问题,本文给出了基于可见光通信的解决方法。本文主要在学习白光LED的物理特性和调制特性的基础上,利用光载波调制方式,建立室内光载FM广播通信系统,在提供照明的同时实现室内FM广播通信。在信道通信链路和信道建模研究的基础上,分析了室内照度分布。论文研究的一个创新点是提出LED非线性对FM广播信号的影响,通过实验数据测量出LED输入电流和输出光功率的非线性曲线拟合出传输函数,首次给出了LED非线性对光载FM广播信号的理论分析。本文给出的可见光载FM广播可以充分利用现有调频广播设备,利用可见光通信本身的优点,克服射频广播的电磁干扰和使用受限等缺点进行室内通信。基于系统设计、理论分析和计算机软件MATLAB对系统进行仿真和论证,得出调频指数和调制指数对载噪比和信噪比的影响程度和此系统更适合传输宽带调频信号的结论。最后在实验室的环境下,搭建了基于白光LED的室内可见光载FM调频广播通信系统实验平台,通过实验论证系统可行性。
[Abstract]:Visible Light Communication (VLC) is a new wireless optical communication technology based on white light LED. It can solve the problem of spectrum resource shortage caused by the rapid development of radio frequency frequency (RF) communication, and it can also be applied in the environment where radio frequency signal can not reach or use is limited. To meet the specific communication needs of people, FM Frequency Modulation (FM) broadcasting has been paid attention to and widely used in many countries since its birth, and the technology is becoming more and more mature. FM broadcasting uses high frequency electromagnetic waves to transmit signals, which has a wide range of coverage and simple equipment. But at present there are some problems. For example, the reception is vulnerable to electromagnetic interference from other equipment, the electromagnetic shielding of tall buildings, the restriction of environmental use such as hospitals and aircraft, etc. In view of the above problems, This paper presents a solution based on visible light communication. Based on the study of the physical and modulation characteristics of white light LED, an indoor optical FM broadcast communication system is established by means of optical carrier modulation. The indoor FM broadcast communication is realized while providing illumination. Based on the research of channel communication link and channel modeling, the indoor illumination distribution is analyzed. One innovation of this paper is to propose the influence of LED nonlinearity on FM broadcast signal. The nonlinear curves of the input current and output optical power of LED are measured by experimental data to fit the transfer function. The theoretical analysis of LED nonlinear FM broadcasting signal is presented for the first time. The visible light FM broadcast can make full use of the existing FM broadcasting equipment and make use of the advantages of visible light communication. The system is simulated and demonstrated based on system design, theoretical analysis and computer software MATLAB. The influence of FM index and modulation index on carrier noise ratio and signal-to-noise ratio and the conclusion that this system is more suitable for transmitting wideband FM signal are obtained. Finally, in the laboratory environment, The experiment platform of indoor visible FM broadcasting communication system based on white light LED is built, and the feasibility of the system is proved by experiment.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN929.1;TN934.2

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