System and method of obtaining random jitter estimates from measured signal data

Abstract

A method of estimating random jitter from measured samples of a transmitted data signal includes a first step of obtaining a plurality of measurements (e.g., pulse widths) for selected signal edges within a transmitted data stream, where the data stream comprises a repeating data pattern having a known bit length and known number of rising edges, and wherein the time difference between adjacent measurements is determined by an event count increment equal to an integer multiple of the known number of rising edges. A time interval error (TIE) value is then computed for each measured signal edge and transformed into corresponding frequency components that are representative of both noise floor and multiple distinct frequency peaks. Noise floor is isolated and the power of the noise floor may be computed to provide an estimate of random jitter variance, from which the standard deviation may be calculated.