新式Pre-distorted 4-ASK調變格式之LED可見光通訊技術

Using Pre-distorted 4-ASK Modulation LED-based Visible Light Communication (VLC) Technology

葉建宏(Chien-Hung Yeh) ； 劉彥良(Yen-Liang Liu) ； 劉昱夆(Yu-Feng Liu) ； 鄒志偉(Chi-Wai Chow)

《電腦與通訊》 149期 (2013/02) Pp. 87-93

摘要

由於發光二極體（LED）的高亮度、低成本效益、及較長使用時間等優勢，因此未來將取代照明用螢光燈具成為新一代照明用元件。相對地LED可見光通訊技術也成為近年來最新的通訊領域研究議題，因為LED除了可作為照明用之外，如再經過適當的光信號調變處理後，其同時可提供網路通訊之功能。但因照明用自光LED受自身的Phosphor磷光粉影響，其有效的3 dB頻寬僅約1 MHz左右，此對於未來提供較寬頻的LED可見光通訊將是一大挑戰，因此在本文內我們提出新式Pre-Distorted 4-ASK調變格式與數位信號濾波技術則可達到20倍頻寬使用效率，其信號調變技術、信號輸出效能及光收發模組設計將於本文中作詳細之介紹。

關鍵字

可見光通訊 ； 數位信號處理 ； Pre-distorted ASK調變

並列摘要

Due to the advantages of high brightness, cost-effectiveness and long lifetime for light-emitting diodes (LEDs), the LEDs will be used for lighting in the future to replace the traditional fluorescent light. Hence, the LED not only can provide lighting, but also can supply network communication after properly signal modulation and signal processing. However, the 3 dB bandwidth of LED was around 1-MHz due to its phosphor effect. This issue will be a challenge in LED visible light communication (VLC) system. Here, we propose and demonstrate a novel pre-distorted 4-ASK modulation technique and digital filter technology to increase 20 times enhancement of the direct modulation speed of phosphor LED for VLC. Besides, the signal modulation method, output performance and LED-based transceiver (TRx) have also been discussed in this paper.

並列關鍵字

Visible Light Communication (VLC) ； Digital Signal Processing ； Pre-distorted ASK Modulation