Real-time Audio And Video Visible Light Communication System Based On Directshow

As a new green transmission method, Visible Light Communication (VLC) is energy-saving,environmental-friendly, safe to human eye, and produces no electromagnetic pollution, and so on.VLC transmits information by imposing signal with different amplitude onto LED, which makes thelighting function and communication function realized at the same time. Nowadays, with theincreasing dependence on real-time information, the technology of real-time audio and videoacquisition and its transmission over network is becoming more important.Based on the VLC technology, this paper designs a kind of optical transceiver using Ethernetinterface and DirectShow software development kits (SDK), supporting full duplex communication.With the blue LED employed as light source, a point-to-point visible light channel supporting10Mbps adaptive data rate is established between two PCs, and a real-time audio and videotransmission system is also proposed. The work of this paper is mainly reflected on the followingaspects.(1) As the key components in optical communication, the characteristics of LED and PDdevices are studied at first. Combined with Ethernet interface, the optical transmitting circuit andreceiving circuit is designed, and the performance of optical transceiver is tested. The paper alsoanalyzes the feasibility of real-time audio and video data transmission.(2) A transmission link oriented connection is estabilished using DirectShow SDK based onTCP and Socket technology. Meanwhile, the reliability of the developed application is tested.(3) A real-time audio and video communication system based on VLC is built. Thetransmission distance is0.15m, and the network packet loss rate is0, while the bit error rate isbelow10-3. This paper also presents an Ethernet wireless accessing method using VLC.