Research And Design Of Underwater Dualchannel SDI High-definition Video Optical Transceiver

The ocean is rich in resources,with the increasing depletion of non renewable resources,the development of marine resources is increased.The great development value of the marine resources promotes the development of the marine exploration equipment.The high definition video surveillance is an important part of the marine exploration equipment.Through high-definition video surveillance can be more clearly understand the underwater world,so as to promote the rapid development of deep sea aquaculture,seabed operations,seabed resource development and other industries.In view of the complexity of the marine environment,it is urgent to need an ocean monitoring system with high resolution(such as 720P/1080P),long transmission distance,good real-time performance and strong anti-jamming capability.The system is divided into two parts: the deck receiving system and the underwater transmitting system.The underwater transmitting system is mainly responsible for the collection of video data and sensor data,and complete the data multiplexed.Then the data is sent to the deck receiving system by using the optical fiber.At the same time to complete demultiplexing reverse control data.The deck receiving system is mainly responsible for receiving data and demultiplexing,distinguish the video data and sensor data,and outputs the received data to the HD-SDI video monitor.At the same time to send control commands to the underwater transmission system,.Firstly,through the analysis of the current demand and technical conditions,the thesis demonstrates the research value of underwater high-definition optical transceiver.Then introduces the related principle and system structure of the SDI high-definition optical transmitter,puts forward a development scheme of the underwater dual-channel SDI high-definition video optical transceiver,and introduces the hardware design of the system and the logic design of the FPGA.The system uses the Xilinx Kintex-7 series FPGA as the master chip,uses the HD-SDI equalization/drive circuit to ensure the transmission of HD-SDI signals,uses the clock circuit to configure the system clock,uses the serial transceiver circuit to realize the receiving and sending sensor data and control signals,uses the SFP+ optical module circuit to complete optical-electrical signal conversion.The logic design of FPGA is developed by Verilog language,and uses the internal GTX transceiver + SMPTE SD/HD/ 3G-SDI IP core to receive and send the HD video data;the design of reset module to avoid the system into a metastable state;the design of HD-SDI video synchronization module to ensure effective video data integrity;the design of HD-SDI video timing information extraction module to ensure the video sequence and video data alignment;uses the data encapsulation and encapsulation module to complete the multi-channel data transmission;uses the comma characters control module and data alignment module to ensure the consistency of the data at the receiver and transmitter sequence.The key and difficult point of the design is the design of GTX transceivers,the design of HD-SDI video related modules,the reuse of multiplexed data and the design of demultiplexing.Finally,the thesis describes the debugging process and the result of the system,including HD-SDI receive/send module test,bit error rate test,real-time transmission test,color bar test and video test.And finally realization of real-time transmission of two-channel 25 fps 1080P HD-SDI video and eight-channel business data.The test result show that the underwater dual-channel SDI(Serial Digital Interface)high-definition video optical transceiver has the characteristics of high resolution,long transmission distance,good real-time performance etc.