The Research Of The Digital Video Transmission System Based On Sub Carrier Modulation

With the development of the economy, safety and protection system has been more and more widely used in our daily life. The video monitor system is one of the most important parts of the safety and protection system, currently most of the video monitor product is designed to use in the short range video monitor, we lack an effective way used in the long range video monitor.To solve this problem, we designed a new long range video monitor system, it is not just the monitor distance is very long, the system also solved the two main problems in the present used system: insufficient of the bandwidth and too much cost. The new system has a good performance in the multi-points long range video monitor job; it can also be used as a short range video monitor system.This system is based on an analog video transmission system, it adopts the technique of sub carrier modulation, which is the integration of the optical and the electrical modulation techinique, because of the ingenious design of the modulation mode, the system fully used the advantages of the optical and the electrical modulation, and the use of digital processing in video signal process greatly raises the stability of the system and proof the high quality of the video signal. In this article we finished these jobs: the design of the whole system, it includes the design of the work flow, the determine of the main technique, the design of the three kinds of key points, and also the simulation of the PCB board, the board works at a very high frequency, so we use the method for the high speed circuits in the simulation. With the cadence EDA tools, we focus on the problems of reflection, crosstalk and time sequence, finding the rules to keep signal integrity, and use the results to direct the design of the PCB board.