增加LED 可見光通訊傳輸速率的方法

Abstract

本篇論文在探討如何利用數種方式來使LED傳輸速率達到更函快速的效果。LED近來成為未來照明的主流之一，由於特殊的構造可以經由調變電流、電壓的方式來傳輸資訊，但由於元件本身的限制還有經過開放空間傳輸所造成波形失真等問題讓其傳輸速度無法達到我們的需求。本論文第一章會概述可見光通訊發展起因以及將來的可能性。第二章介紹LED發光原理以及現有使用LED做傳輸光源的塑膠光纖，另外在結尾我們將會提到用來結合LED的通訊調變格式。在第三章中我們會說明關於其他實驗室所提出來有關改善LED傳輸速率的方法。第四章提到我們實驗的三個主軸，利用預先改變波形以及結合電路設計來達到改善傳輸速度的效果和提出結合調變格式的架構，讓速度可以增數倍以上。第五章將展示我們三個主軸實驗所做出來的結果並深入探討其中的細節，最後在第六章會做一個總結論並且提到未來我們還需要努力的方向。

In this thesis, we present several methods to improve the data rate of the LED visible light communication (VLC). In the near future, LED will be the major source of lighting. Hence combining LED with communication system can be desirable for future LED market. LED can be directly modulated at a relatively high speed when compared with the present fluorescent lamps. However, it is still not high enough for the ever-increase bandwidth demands for in-door communication. In this thesis, we will present several methods to improve the modulation data rate of the commercially available high-brightness white LED. A brief introduction of VLC is given in chapter 1. The principle of LED, plastic optical fiber and communication modulations are described in chapter 2. LED VLC results by other research groups will be presented in chapter 3. The experiential descriptions for improving the data rate of LED VLC by pre-distortion, post-equalization are shown in chapter 4. In chapter 5, we will show our experimental results. At last, a brief conclusion and future works will be given in chapter 6.