Patent ID: 8538257
Filing Date: 2013-09-17
Classification: H04B

Abstract:
1. A clock and data recovery (CDR) circuit configured for detecting optical failures in a passive optical network (PON), comprising: an over-sampler for over-sampling an input continuous data signal to generate a bit stream; a phase estimation unit (PEU) for computing from the bit stream a phase position of the input continuous data signal relative to sampling clock signals; a digital filter for computing a phase control code based on the phase position; a statistical accumulation block (SAB) for performing jitter analysis using the phase position and the phase control code and providing a plurality of statistical measures of at least a jitter frequency component and a jitter amplitude component in different frequency ranges; and a processor for analyzing aggregation of the statistical measures to detect optical failures in the PON and determining a root cause of each of the detected optical failures.