Research For Data Transmission System Based On Analog Video Channel

Analog video technology is the most mature video transmission and displaytechnology in the world, which has the highest penetration. In recent years, althoughthe analog video technology is gradually being replaced by digital video technology,but analog video transmission equipment penetration is still far ahead of the othertechnologies. Since many reasons such as television programs off the air in themidnight, the analog video channels often have idle period, which is a huge waste ofchannel resources. Technology transmitting data through the idle period of the analogvideo channels, like teletext, greatly improves the utilization of analog video channels.Especially people can realize these features without additional equipment, which alsohas a great cost savings.Firstly, research the traditional teletext and PAL analog video transmission theory.Describe the scheme of data transmission through PAL analog video channel.According to PAL analog video channel features and Nyquist sampling theorem, comeup with the modulation scheme forced on the amplitude value of the pixel luminance,while based on the amplitude modulation method, design the judgment schemeaccording to the actual situation.Because FPGA chips used in this article, this paper do a brief introduction SOPCand NIOS II soft-core technology and features. Then paper describes the functiondesign of analog video channel data transmission system, including: design sense,design methods and realization process of main function module on sending circuit andreceiving circuitFinally, this paper introduces the design of hardware platforms, including: themain chip selection and function introduction. Using hardware platform do thetransmission experiments. By analyzing the data of experimental results, obtained theimprovement scheme to achieve this indicator.