基于LED的室内可见光通信系统的研究与设计

发布时间：2018-04-04 14:07

  本文选题：白光LED　切入点：可见光通信　出处：《华中师范大学》2014年硕士论文

【摘要】：VLC (Visible Light Communication)技术作为一种新的带宽无线通信技术,自2000年横空出世以来,因为具有高速调制特性、不占用无线电频谱资源、安全性高等独特优势,受到的关注度越来越高,已经成为国内外的主流设备商、各大学和科研机构的研究热点,拥有巨大的发展潜力,在未来的实用化前景相当值得期待。目前对VLC技术的研究目前主要分为室内和室外两大领域,本文主要对基于白光LED的室内可见光通信系统的设计与实现进行了研究。 本文首先简要讨论了VLC技术的研究背景与意义和国内外研究现状,接着对白光LED的光源特性进行了研究,是后面LED驱动电路的设计的理论基础,然后重点对室内无线信道特性进行了分析,具体包括室内通信系统的链接方式、光路径、信道冲击响应等,选择了最简单的直射视距作为本系统的链接方式。通过分析相关文献,了解到影响系统通信性能的主要因素是多径效应产生的码间干扰,因此提出引入具有强抗多径时延能力的OFDM (Orthogonal Frequency Division Multiplexing)技术,并详细介绍了它的基本原理,最后设计了一套基于白光LED的室内可见光通信试验系统,其中,PC机用来发送和最终接收数据,调制和解调模块是基于Quartus Ⅱ11.0开发环境通过FPGA (Field Programmable Gate Array)实现的,与传统的通过硬件电路实现相比更简便快捷,且性能更优越。 本文重点是整个系统的设计工作,首先,设计了LED驱动电路、前置放大电路和滤波与主放大电路,同时为了克服调制信号可能存在的变形,在调制模块和驱动模块间加入了高速比较器对信号根据设定的标准电平进行整形处理,得到标准的矩形方波；其次,OFDM系统的设计,具体包括各个小模块到最后调制和解调两大模块的整体实现：最后,完成整个系统的搭建,通过比较PC机发送和接收的数据是否相同来判断系统能否正常工作,该实验系统的实现为后续进一步系统的优化与实用化提供了一定的参考和借鉴价值。
[Abstract]:As a new bandwidth wireless communication technology, VLC visible Light communication technology has attracted more and more attention since its birth in 2000, because of its unique advantages such as high speed modulation, no use of radio spectrum resources, high security and so on.It has become the mainstream equipment at home and abroad, universities and research institutions of research hot spots, has a huge potential for development, in the future practical prospects are worth looking forward to.At present, the research on VLC technology is mainly divided into indoor and outdoor areas. This paper mainly studies the design and implementation of indoor visible light communication system based on white light LED.Firstly, this paper briefly discusses the research background and significance of VLC technology and the current research situation at home and abroad. Then, the characteristics of white light LED are studied, which is the theoretical basis of the design of LED driver circuit.Then the characteristics of indoor wireless channel are analyzed, including the link mode of indoor communication system, optical path, channel impulse response and so on. The most simple direct line-of-sight is chosen as the link mode of the system.By analyzing the related literatures, it is found that the main factor affecting the communication performance of the system is the inter-symbol interference (ISI) caused by the multipath effect. Therefore, the OFDM orthogonal Frequency Division Multiplexing technique with strong anti-multipath delay capability is introduced, and its basic principle is introduced in detail.Finally, a set of indoor visible light communication test system based on white light LED is designed, in which the PC is used to transmit and receive the data, and the modulation and demodulation module is realized by FPGA Field Programmable Gate Arraybased on the development environment of Quartus 鈪，

本文编号：1710282