Exploration of Coherent Detection Technology for 100G Optical Energy Signal under FPGA Design

Major equipment manufacturers are increasing their research and development investment, and have successively launched solutions for 100G (Gigabyte) fiber optic transmission systems. However, the 100G DP-QPSK (Dual-polarization Quadrature Phase Shift Keying) optical transmission system is an ultra long distance transmission project, and its implementation is very difficult. This article provided a detailed explanation of the specific modulation and coherent reception theory of DP-QPSK, and briefly explored its application in the digital domain. This article provided the hardware design of the coherent detection system, including the overall design of the system, power supply design, clock design, monitoring design, etc. It focused on the core power design of DSP (Digital Signal Process), the design of RF (Radio Frequency) analog-to-digital converter clock, and the design of DSP clock. In different rounds of testing, the bit error rate was 0.09% for the 10th round and 0.06% for the 20th round. This article laid a solid foundation for the research on high-precision clock design and FPGA (Field Programmable Gate Array) design of high-speed analog-to-digital converters.