Clock conversion for burst-mode digital coherent QPSK receivers in a PON upstream transmission with a 100-ppm clock mismatch

This paper presents a clock conversion scheme for burst-mode digital coherent QPSK receivers in an asynchronous PON upstream and confirms its validity. The scheme converts the number of samplings of transmitted signal based on the clock at Rx. We demonstrate the proposed scheme in a realistic environment that emulates a fixed clock difference by two independent synthesizers at Tx and Rx mixed together with clock jitter induced by 20-km fiber transmission. In the real-time demonstration, a digital coherent receiver employing the proposed clock conversion successfully receives 330-mu s burst QPSK frames over 20-km transmission in the presence of a 100-ppm clock mismatch. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

This paper presents a clock conversion scheme for burst-mode digital coherent QPSK receivers in an asynchronous PON upstream and confirms its validity in a realistic environment. The scheme successfully receives burst QPSK frames in the presence of clock mismatch and fiber transmission-induced clock jitter.