Research And Design Of Digital Optical Surveillance System Based On FPGA

At present, in the complex industrial control field, the amount of monitoring information to be collected is becoming more and more, traditional twisted-pair cable has not been competent for the task because of its limited capacity, poor anti-interference ability, large delay of long-distance transmission. With further development of optical communication technology in recent years, optical fibers gradually replace the traditional cables for advantages such as wide frequency bandwidth, large capacity, strong anti-interference ability, long relay distance, etc.Combined digitalizing technology and optical fiber communication technology, a high-quality, uncompressed eight-channel optical fiber monitoring system is proposed in this paper. The system is based on Time Division Multiplexing technology. With high-speed serial digital transmission of 8B/10B encoding mode in optical fiber line, it is possible that multiple video, audio, and data signals can be transmitted simultaneously in a single optical fiber. The system is divided into two parts, optical transmitter and receiver. The hardware part includes ten components: video buffer amplifier, video A/D or D/A converter, audio codec, serial/parallel converter, parallel/serial converter, fiber optic transceivers, FPGA controller, data interface, power supplier and LED displayer. At the same time, Multi-stage lightning protection circuits are deployed in every interface. The design uses the industry-specific high-speed circuit design software, Cadence, the PCB board is four-layer wired to ensure integrity of high-speed signals. Software part mainly includes 8B/10B encoding and decoding module, high-speed TLK1501 module, voice processing module. Verilog HDL and schematic is mixed as programming method for hardware circuit description. Simulation, synthesis and download are all has been achieved in Quartus II.The test results indicate that the optical transmission system stably and reliably implements real-time, high-quality transmission of eight-channel video, audio, data signals, which meet industry design standard and can be widely applied to various complex and harsh environments.