Comparison of Feedback and Feedforward Clock Recoveries for Ultra-Fast Synchronization in Passive Optical Networks

Abstract

We compare digital non-data-aided feedback and feedforward clock recoveries for burst-mode operation in high-speed PONs. For 56 GBd NRZ, PAM2, and PAM4, we demonstrate that a clock frequency offset of 20 ppm can be synchronized within 40.96 ns.