Design And Implementation Of Clock Recovery Algorithm For High Speed Optical Transmission System

Flexible optical transmission network FlexO can solve the problem that 100 Gpbs Optical Transport Network(OTN)cannot transmit 400 Gbps services.However,in the specific implementation process.In the 400 Gbps optical transmission network,in the process of recovering OTU4 service data from the line-side OTUC4 service,the customer clock needs to be recovered through the service code stream,and the recovered OTU4 service is sent to the customer-side optical module through the corresponding interface.Based on the phase-locked loop technology,this paper designs and implements a new all-digital clock and data recovery scheme.It controls the way the phase-locked loop frequency synthesizer generates the desired frequency by changing the control output of the algorithm to complete the task of clock recovery,and realizes the re-setting of the data stream by the recovered clock.Through the control output of the algorithm,the frequency synthesizer is controlled to generate the clock to be recovered in real time.The simulation and actual test prove that this solution can effectively meet the clock recovery requirements in FlexO,complete the real-time recovery of OTU4 service data frequency,and can respond to customer frequency deviations of more than 90 ppm.The article mainly discusses:(1)The basic principles of the phase-locked loop are described,and a variety of common clock data recovery techniques and phase-locked loop frequency techniques are introduced.(2)The basic principles of the implementation of the FlexO high-speed optical transmission system.It divides the functions to be implemented in this CDR,establishes the overall design ideas.(3)Establish a model and input model based on the FIFO data transmission system,and transform the design of the clock recovery algorithm into the design of the algorithm.(4)The basic principle of the proportional integral(PID)control algorithm is described,and the algorithm function is verified by Matlab.(5)Complete the CDR digital design based on the FIFO water level control algorithm,and test the performance of the CDR design in this paper...