以相機為可見光通訊接收器之應用與研究

Abstract

LED的調變頻寬足夠做為訊號源來傳遞訊號。可見光通訊在LED的普及和日漸高升的無線通訊的需求，但無線電波的頻譜短缺下，可見光通訊提供了一個新的解決辦法。除此之外，相機可以說是手機的基本配備了，以相機鏡頭作為接收器，比起(photodiode)PD更容易取得。 本文在第二章，從相機的滾動式快門效應如何應用在可見光通訊，到解調流程時，如何從二維的圖像資料轉為一維的陣列，並以兩種從影像處理法改良而來的二值化方法，搭配消光比增強，與一個全新的閥值演算法比較處理時間和誤碼率。第三章是關於一種增加傳輸速率的以相機為接收器的偏振多工可見光通訊系統。第四章介紹以手機APP進行的實時可見光通訊應用，並針對測試結果進行分析討論。最後第五章為總結及未來工作。

As wireless communication is becoming more and more important in our daily lives, the traditional radio-frequency (RF) communication spectrum is nearly occupied. And the light emitting diode (LED) is replacing the traditional lighting sources in now days. For these two reason, visible light communication (VLC) is the proper solution.Besides, the mobile phone embedded with complementary-metal-oxide-semiconductor (CMOS) camera become common. It is more easy to get camera than photodiode(PD) as receiver. In this thesis, we proposed and demonstrated different techniques to enhance the performance of VLC. In Chapter 2, we introduce using the rolling-shutter effect of the mobile-phone camera for the VLC. We also show how to demodulate and compare different thresholding schemes for defining the logics of the rolling shutter pattern obtained by the mobile phone camera. In Chapter 3, in order to increase transmission data rate, we propose a polarization multiplexing visible light communication system using camera as receiver. In Chapter 4, we implement a real-time communication system by using APP on mobile phone. And we discuss for the experiment result. Finally, conclusion and future works are presented in.