Design, Implementation And Experimental Research Of Visible Light Communication System

Visible light communication (VLC) technology uses visible light emitting diode (LED) as a light source, which emits light shading and carrying high-speed signals to transmit information. VLC technology is a technology that combines illumination and communication. Its huge bandwidth of spectrum can alleviate the problem of running out of radio frequency (RF) spectrum; Moreover, VLC has the mobility and flexibility of RF wireless communications and the high-speed and high capacity characteristics of optical fiber communications. And it can be applied to the environments which is sensitive to electromagnetic wave and areas concerning information security. These features make it an important research value and broad application prospects.As an emerging wireless communication, there are still some key issues to be resolved in VLC. This paper focuses on theoretical and experimental studies of VLC indoor channel modeling, background noise filtering and setting up optical communication systems. The main achievements are listed as follows:1. By the use of multipath-reflection channel model along with Monte Carlo ray tracing method, the impulse response is built for an indoor VLC channel. The results show that signals of different wavelengths have a similar path loss under the indoor multipath channel environment. The blue spectrum has a smaller root mean square (RMS) delay spread, and green spectrum is with greater3dB channel bandwidth.2. By measuring and analyzing the three main indoor ambient light noise and comparing a variety of digital filter performance, Kaiser window is chosen as the system digital filter. Through experiments, Kaiser window system can effectively reduce the affect from ambient light noise, and the bit error rate (BER) can be reduced by an order of magnitude under the best situation.3. Comprehensive study of the principles of each component of VLC system. LED cooling modules, LED optical design and filters designs are completed. The selected devices are designed to complete the high-speed transmission module and high-speed receiver module. VLC system has been completed, and implementation of high-definition video transmission experiment is successfully done.