The Design Of Underwater Digital Video Transmission System Based On SOPC

This dissertation aims to design a digital video transmission system for underwater exploration, which combines the functions of video real-time acquisition, video high compression processing and data real-time transmission.Our country has a large range of ocean territory, which covers over 3 million square meters. Oceans contain rich resources, which play an important role in the development of economy of our country. Meanwhile, oceans that are considered as the inner space of the earth play an important role in military affairs.The transmission rate of current acoustic modem is lower than 10kbps. The key technologies of transmitting real time video images through acoustic channel are as follows: efficient video image compression technology; efficient acoustic modem. The efficient video image compression technology can be divided into two components: video image compression algorithm and efficient video compression circuit, which is the research work of this dissertation.Underwater digital video transmission system includes three modules: video capture, video compression and data transmission.Our system design each module by using SOPC technology and following the top to bottom design philosophy, which could benefit the update and maintenance of the system. In the video capture module, the IP core controller of camera and SAA7113 has been finished. In the video compression module, I introduce the current advanced image compression technologies and one efficient underwater video image compression technology, the compression rate of which could be 250:1 to 500:1. Then a DSP development program based on FPGA is proposed after the research of the hardware realization of video compression. Parts of the hardware realization is finished with the EDA tools, like DSP Builder, ModelSim. In the preprocessing step, I have accomplished the model creation and simulation experiment of Daub 5/3 wavelet translation. The model creation and simulation experiment of DPCM coding have been finished in the intra frame coding. The model creation and simulation experiment of block matching are finished in interframe coding. All these work has created a foundation for the further research. After that , according to the characteristics of the collaboration of duel-FPGA and dual-NIOS, we design the transmission interface to provide a software and hardware interface for the acoustic note.In the end, a concludsion of this dissertation and a prospect for the future are given.