可见光通信信道特性与传输方法研究

发布时间：2018-01-06 19:08

本文关键词：可见光通信信道特性与传输方法研究　出处：《中国科学技术大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着近年来无线数字终端市场的迅速发展,无线数据量呈指数增长,已有带宽资源已无法完全满足当前的通信需求,无线频谱资源紧张的问题日益突显。与此同时,发光二极管(Light Emitting Diode,LED)照明技术凭借其更高的电光转换效率和更长的使用寿命等特点,得到了各国政府的推广。基于LED的可见光通信(Visible Light Communication,VLC)技术作为一种新兴的无线通信技术,它的优点包括:巨大的带宽资源;照明的同时提供上网通信功能;无电磁污染;更好的保密性等。本文主要研究了基于正交频分复用技术(Orthogonal Frequency Division MultiPlexing,OFDM)的室内VLC系统。在VLC信道特性分析的基础上,本文提出了一种适用于VLC的自适应OFDM传输方法,并搭建了基于现场可编程门阵列(Field Programmable Gate Array,FPGA)的通信链路进行功能验证和性能分析。本文首先对VLC系统中的关键组成部分LED光源、无线光信道和光电检测器(Photo Detector,PD)进行了介绍和建模。三者共同决定了 VLC系统的通信性能,为了便于在电域对系统进行性能分析,本文提出了广义可见光信道。广义可见光信道的频率响应包括LED光源、无线光信道和PD的频率响应。通过对广义可见光信道的理论分析,提出了广义可见光信道的频谱响应包络不变特性(ResPonse Mask Invariant Characteristic,RMIC)。并通过完整的实验和分析,验证了广义可见光信道的RMIC特性。接着在RMIC的基础上,本文提出了一种应用于VLC系统的自适应OFDM传输方案。在此基础上,通过搭建的实验链路对方案进行性能分析,实验结果表明,该方案具有较低的复杂度,且本文的传输方案能更好地利用可见光信道的带宽资源,提升系统的通信性能。最后在前文的基础上,本文实现了基于FPGA开发板的VLC传输链路的搭建。本文给出了链路的设计目标并对链路的总体结构进行了介绍,通过分析和实验确定了链路的关键参数,并详细介绍了链路的工程实现。本文根据链路功能的不同,将实现的链路分为可见光OFDM基带链路、可见光自适应OFDM链路和可见光OFDM实时通信链路,并依次进行了实验测试分析。
[Abstract]:With the rapid development of wireless digital terminal market in recent years, the wireless data volume has increased exponentially, and the available bandwidth resources can not fully meet the current communication needs. The shortage of wireless spectrum resources is becoming increasingly acute. At the same time, light emitting diodes (LEDs) light Emitting Diode. LED) lighting technology with its higher electro-optic conversion efficiency and longer service life and other characteristics. The visible Light Communication is based on LED. As a new wireless communication technology, VLC technology has the following advantages: huge bandwidth resources; While lighting provides Internet communication function; No electromagnetic pollution; This paper mainly studies orthogonal Frequency Division MultiPlexing based on orthogonal frequency division multiplexing. Based on the analysis of VLC channel characteristics, this paper presents an adaptive OFDM transmission method for VLC. And the field Programmable Gate Array based on field programmable gate array is built. FPGA) communication link function verification and performance analysis. Firstly, the key component of VLC system LED light source. The wireless optical channel and photo detector PDD are introduced and modeled, which together determine the communication performance of VLC system. In order to facilitate the performance analysis of the system in the electrical domain, a generalized visible light channel is proposed. The frequency response of the generalized visible light channel includes the LED light source. Frequency response of wireless optical channel and PD. Theoretical analysis of generalized visible light channel. The spectral response envelope invariance of generalized visible light channel is proposed. The RMIC characteristics of the generalized visible light channel are verified by the complete experiments and analysis. Then, based on the RMIC. In this paper, an adaptive OFDM transmission scheme for VLC system is proposed. Based on this, the performance of the scheme is analyzed through the established experimental link, and the experimental results show that the proposed scheme is based on the proposed scheme. This scheme has lower complexity, and the transmission scheme in this paper can make better use of the bandwidth of the visible light channel, improve the communication performance of the system. Finally, on the basis of the above. This paper realizes the construction of VLC transmission link based on FPGA development board, and gives the design goal of the link and introduces the overall structure of the link. The key parameters of the link are determined through analysis and experiment, and the engineering implementation of the link is introduced in detail. According to the different link functions, the realized link is divided into visible light OFDM baseband link. The visible light adaptive OFDM link and the visible light OFDM real time communication link are tested and analyzed.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.1

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