Real-Time FPGA Demonstration of PAM-4 Burst-Mode All-Digital Clock and Data Recovery for Single wavelength 50G PON Application

We demonstrate a burst-mode all-digital clock and data recovery for 26.20546-GBaud PAM-4 signal with real-time FPGA processing. With a free-running ADC, clock recovery is achieved with 32 symbols based on the squaring timing recovery algorithm.