On The Study Of Techniques Of Visible Light Video Communications System

Currently, people are in great need for wireless access bandwidth, at the same timetraditional RF technologies are suffering from the lack of enough transmission rate andchannel capacity. The white led light is considered to be the next generation light source due tohigh brightness, low power consumption and long service life. Furthermore, it can providehigh-speed data transmission as visible light communication with wide modulation bandwidth.Because visible light communication can provide high speed wireless access and illuminationsimultaneously, it has an important value and broad prospects for research.Considering the characters of optical wireless transmission, a kind of optical wirelessvideo transmission system based on FPGA is studied and designed. Then key techniques forrealizing it are investigated in this paper. The mainly content is as follows: Firstly, accordingto function and performance requirements, choosing suitable hardware platform, and figuringout a whole designing proposal for this system are done. Secondly, a kind of channel framesuitable for white light communication channel is proposed and the correspondingtransmission mechanism is introduced. Based on this mechanism the designs of signalprocessing which include scrambling, descrambling, framing and de-framing are finished, thenthe development and simulation of program are finished by using VerilogHDL language.Finally, base on the proposed scheme, the designs of video communication interface, whichinclude video capture, video sending, the communication of USB interface, video receivingand video display are presented. The detailed methods of design and implementation areintroduced, and the debugging results of the design are shown to demonstrate that theproposed design is feasibility and validity.This system is developed by C++and VerilogHDL programming language on MicrosoftVisual Studio2010development environment and the FPGA multimedia developmentplatform. The testing results show that this system has a relatively good stability and strongextensibility. This design can realize the video transmission process correctly, which is apositive exploration for practical application of VLC technology.