Design Of Optical Transmission System For Digital Video Based On FPGA

With the rapid development of computer and communication technology, digital video plays a more and more important role in information society; video transmission system has been applied to many fields such as industrial surveillance, traffic management, videocast, etc. Meanwhile, the scale of single FPGA continues to expand, the complex digital signal processing system on FPGA has become realizable, and therefore the use of video compression and transmission on FPGA has become an optimum section.Combining digital video compression technology with optical fiber transmission, this thesis presents a multichannel digital video transmission system based on LZW compression. Based on video compression technology, time-division multiplexing technology and the serial digital video transmission, the proposed system can transfer eight channels of standard video signal over a single optical fiber. The system adopts a design scheme based on FPGA, The A/D conversion circuit and D/A conversion circuit adopt AD9280 and AD9708 chip, which are high performance from ADI company; the TDMA module, video compression module, video decompression module and line code/decode module are implemented on FPGA; The photo-electric conversion and the electric-photo conversion are implemented by optic transceiver module. The video compression/decompression module is designed by verilog HDL. The input data and output data of compression/decompression module are storaged in FIFO, which is generated by Core Generator. The system adopts CIMT line code, and CIMT code/decode module is designed by verilog HDL. The frame synchronization is realized by digital phase locked loop. The FPGA modules are simulated under ISE8.2 and Modelsim environment and in the end, the whole debugging and testing of system is done using Spartan-3E starter kit board. Experiment demonatrates that the system is stability and has a good effect of real-time transmission. It is a good practical scheme for security and surveillance systems.The system processing speed is improved greatly with the advantage of FPGA parallel processing, and the system have many characteristics such as high processing speed, high integrated level and strong antijamming ability.