Design And Realization Of Digital Video Optical Transmitter

With the development of optical communication technology, digital optical transceiver as a effective and reliable method of transport signal has been applied more and more widely, and the technique has been becoming maturer and maturer. Due to its characteristics of intuitionistic and convenient and its wide applying range, video surveillance system has been developing rapidly recently. Now, digital video optical transceiver has become indispensable in the video surveillance system..The design of digital video optical transmitter in this paper is used in video surveillance system. It can transmit the video signal received from video camera through fiber. It also can receive the control signal from fiber and transmit the signal to video camera through RS-422 or RS-485 serial interface. The design of the optical transmitter include two main parts: video signal processing and control signal processing. In the part of video signal processing, the design is realized in the methods of analog to digital conversion, linear encoding and serialization. The linear encoding adopts the 8B10B coding scheme and is realized by programming of Verilog HDL in CPLD. The part of control signal is composed of the circuit of demodulation and the circuit of transmission system. The circuit of demodulation uses HC4046 Phase-Locked Loop. The transmission interface use the chip MAX489 which is produced by the company called MAXIM. The transceiver module is NTR-22114T which can transmit video signal and receive control signal simultaneously.Based on the design requirements, this design analyses the system, choose the appropriate device, design the schematic diagram and design the printed circuit board with PCB layout principle and actual experience. There is also the linear coding scheme programming of Verilog HDL in CPLD.