The Design And Analyse Of Image Signal Transfer Technology Based On A Ten Thousand Meters Coaxial Cable

As the development of industry and economy, the consumption of mineral resource increases quickly. The shortage of land mineral makes people find new resource in the ocean. The task "the development of TV grab bucket -cabled observation and sampling system benthal 6000 meters deep" is belong to Nation "863" plan. This task meets the need of ocean mineral resource reconnaissance.The advantage of The TV grab bucket is directly benthal observation and exactly grab under remote control .In this paper, we address the study thought, design precept and implemental method of the image transform part.This paper is about the study of benthal long distance image transform .We get the image video frequency signal through CCD under water. The signal is transferred to image monitor on the deck through 1000 meters ' coaxial cable. At the same time ,we provide a two direction digital signal passage, which can transmit the command and condition between deck control system and benthal control system.Digital transmit scheme is used in the image transfer part .For the sake of long distance transfer, we select HDB3 as the transfer code. As the attenuation of coaxial cable in high frequency, it's transferring code stream is limited in lMbps,so we use image compress and decompress technology to reduce the data amount .By analyzing several code commutation precepts, we put up the most suitable method: using PLD. We use CPLD as working object, realize the whole design process of HDB3 compress and decompress.