Hybrid Clock Recovery for a Gigabit POF Transceiver Implemented on FPGA

In this paper, we present a clock recovery system implemented on field programmable gate array and integrated to the Gigabit Ethernet media converter for PMMA SI-POF developed within the framework of the POF-PLUS EU Project. We demonstrate timing synchronizing using only one sample per symbol from a highly distorted and attenuated 2-PAM signal without requiring any sort of preequalization. This is achieved by means of a hybrid analog-digital PLL with a timing error detector based on a modified version of the Müller and Mueller algorithm, a loop filter, and a VCXO.