Blind Oversampling Data Recovery with Low Hardware Complexity

Abstract

The paper is focused on the optimization and implementation of fully digital feed-forward blind oversampling CDR (BO-CDR). Two new phase-decision algorithms are proposed. Their complexity is very low, enabling a very simple and fast implementation even in FPGA, which was used as a development platform as well as a target device for the BO-CDR block. The FPGA-based optimization gave the opportunity to perform on-the-fly optimization under real conditions of target link. This greatly shortened the development time as there were no errors caused by inaccurate simulation models. Measurement results obtained on real links are included showing the jitter tolerance of the proposed algorithms to be comparable to the performance of modern PLL-based CDRs.