Design And Research On Comprehensive Bit Error Ratio Test Platform For Multi Rates

With rapid spread of high-bandwidth services and the advent of the IOT era, the existing communication system has failed to meet the growing business needs. 10 G, 40 G and even 100 G optical transmission system becomes the preferred expansion plan to upgrade the existing network bandwidth for infrastructure operators. And the research and development of the BER test platform for optical modules and optical system has a high practical value.After systematically analyzing the principle of BER test and the PCB layout problem of high speed circuit, this thesis presents the simulation and design, develops a comprehensive BER test platform for multi rates, which has 4 parallel channels and covers the rate range of 2.125G~27.952 Gbps for one channel. The platform is mainly used to test the BER performance of 10 G, 40 G, 100 G optical modules, such as SFP, XFP, QSFP, CFP4 optical modules. The major achievements of this thesis are summarized as follows:(1) According to the relevant requirements and principles of BER test, the thesis designs a comprehensive BER test platform for multi rates. For the purpose of achieving wide rate coverage, use the VSC8248 module and Gearbox module to cover the different rate range.(2) According to the design plan, we have designed the hardware circuit and drawn the PCB layout. What's more, the thesis shows the SI problems of impedance matching and channel bandwidth design which should be paid attention to in high speed circuit.(3) Develop the control program for the platform, including system initialization, human-machine interaction, the algorithm of clock output frequency design, the driver program of main chip and clock chip.(4) In this thesis, we have proposed a test plan for the BER platform, introduced the debugging process and result. And we have analyzed and solved the problems found in the test process, evaluated the platform performance by comparing with the actual product.