가시광 무선통신을 위한 PWM 디밍기반 NRZ 신호전송방식 연구

Abstract

Recently, the visible light communication is being developed for some potential applications in the field of indoor communication system and intelligent transportation system covering vehicle to vehicle / road to vehicle communication, information display, and home networking. Illumination industry incorporating LED is growing up rapidly. It is expected that the market relating to the visible light communication will also grow up with LED development. And application technologies such as visible light communication using LED have been researched in the world. The objective of this study is to propose and experimentally demonstrate a signaling scheme using NRZ coding for visible light communication. The signal format is based on PWM for dimming control and NRZ-OOK signals. The signal waveform is generated using LabVIEW for experiments. The signal format increases slot utilization since the signaling scheme utilizes the off-state of the PWM dimming period. Thereby, the data rate can be increased compared with the case without data pulses during the off-state of the PWM period, at the cost of dimming level. The proposed technique is simple and effective in providing the data transmission with the dimming simultaneously.