System Design And Implementation Of Circuits And Test Analysis Of Wireless Optical Communication

Wireless optical communication is a new type of optical communication technology, the signal is spread in free space. WOC features large capacity, flexible networking, mobile communication, no electromagnetic radiation and anti-electromagnetic interference, which make it become a new hot research direction in the research of optical communication research in recent years.Wireless optical communication mentioned in this paper includes ultraviolet and visible light communication, which uses light emitting diode (LED) as the light source. Currently, the research of the non-strict alignment of wireless optical communication is still in its initial stage. And the research mainly focuses in the study of channel analysis, modulation and off-line experiments. Reports on online real-time communication system are few. So the research on theoretical and experimental of online system in this paper is significant meaningful.Based on the National Natural Science Foundation of China (NSFC) and863program, our main work focuses on the system design of ultravilot and visible light commucication. The main work is as follows.Firstly, according to the characteristics of solar blind ultraviolet channel, we designed and implemented transmit and receive circuits. With the help of the system composed by the circuits, we tested the bit error rate under three cases:without FEC code, with LDPC code and with RS code. The result showed that the channel code can enhance the effectiveness of system performance in wireless optical communications.Sencodly, the paper presents the analysis of characteristics of the white LED and the link classification of indoor visible light. We designed the tranmit circuit and receive circuit based on LED. The circuits mainly include a voltage amplifier, a power amplifier, a photoelectric conversion, a signal amplification and a clock-data restore module. Based on this system, we achieved the longest distance of3.6m, the highest rate of12.5Mbps high-definition video in real time transmission.Lastly, we designed and implemented transmit and receive circuit of a visible light communication stereo audio system. The circuit was tested and the result shows that the system can achieve to transmit and receive HiFi stereo audio in a LOS distance of1.5m.