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.

目錄
摘要 i
ABSTRACT ii
誌謝 iii
表目錄 iv
圖目錄 v
目錄 vii
一、緒論 1
1.1 可見光通訊( Visible Light Communication, VLC)簡介 1
1.2 研究動機 2
1.3 文獻探討 3
二、可見光通訊與CMOS 感光元件 4
2.1 原理介紹 4
2.2實驗架構 6
2.3解調流程 8
2.4閥值(Thresholding) 11
2.4.1 Bradley Adaptive Thresholding 11
2.4.2 自適應二值化(Quick Adaptive Thresholding) 12
2.4.3 消光比增強(extinction ratio enhancement)[14] 13
2.4.4 極值平均法(Extreme Value Average Thresholding) 14
2.5實驗結果與討論 16
2.5.1 誤碼率(bit-error-rate, BER) 17
2.5.2 處理時間 20
三、可見光與偏振多工 22
3.1 偏振原理 22
3.2 實驗架構 23
3.3 實驗結果與討論 24
四、實際應用 26
4.1 實驗架構 26
4.2 解調流程 28
4.3 實驗結果與討論 29
五、結論 32
5.1 結論 32
5.2 未來展望 32
參考文獻 34
著作列表 36

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[2] http://www.lighting.philips.com/main/systems/themes/led-based-indoor-Position ning

[3] http://www.ledinside.com.tw/news/20160419-32398.html

[4] http://www.infocom.tw/Page_20150301_LiFi.htm

[5] Roberts, Richard D. "Undersampled frequency shift ON-OFF keying (UFSOOK) for camera communications (CamCom)." Wireless and Optical Communication Conference (WOCC), 2013 22nd. IEEE, 2013.

[6] Nguyen, Trang, Nam Tuan Le, and Yeong Min Jang. "Practical design of screen-to-camera based optical camera communication." Information Networking (ICOIN), 2015 International Conference on. IEEE, 2015.

[7] Danakis, Christos, et al. "Using a CMOS camera sensor for visible light communication." Globecom Workshops (GC Wkshps), 2012 IEEE. IEEE, 2012.

[8] http://blog.xuite.net/brian923/getter/3408402-CCD+%E5%92%8C+CMOS
+%E6%84%9F%E5%85%89%E5%85%83%E4%BB%B6%E7%9A%84%E5%8D%80%E5%88%A5

[9] http://www.masters.tw/18871/%E6%80%AA%E7%95%B0%E7%9A%84%E6%
9E%9C%E5%87%8D%E6%95%88%E6%87%89

[10] Chow, Chi-Wai, Chung-Yen Chen, and Shih-Hao Chen. "Visible light communication using mobile-phone camera with data rate higher than frame rate." Optics express 23.20 (2015): 26080-26085.

[11] Bradley, Derek, and Gerhard Roth. "Adaptive thresholding using the integral image." Journal of Graphics Tools 12.2 (2007): 13-21.

[12] Wellner, Pierre D. "Adaptive thresholding for the DigitalDesk." Xerox, EPC1993-110 (1993).

[13] Liu, Yang, et al. "Comparison of thresholding schemes for visible light communication using mobile-phone image sensor." Optics express 24.3 (2016): 1973-1978.

[14] Liu, Yang, et al. "Light encryption scheme using light-emitting diode and camera image sensor." IEEE Photonics Journal 8.1 (2016): 1-7.

[15] https://zh.wikipedia.org/wiki/%E5%81%8F%E6%8C%AF%E7%89%87

[16] http://www.ikinamo.net/

[17] Roberts, Richard D. "Undersampled frequency shift ON-OFF keying (UFSOOK) for camera communications (CamCom)." Wireless and Optical Communication Conference (WOCC), 2013 22nd. IEEE, 2013.

[18] Liang, Kevin, Chi-Wai Chow, and Yang Liu. "Mobile-phone based visible light communication using region-grow light source tracking for unstable light source." Optics express 24.15 (2016): 17505-17510.

[19] Lee, Hui-Yu, et al. "Rollinglight: Enabling line-of-sight light-to-camera communications." Proceedings of the 13th Annual International Conference on Mobile Systems, Applications, and Services. ACM, 2015.