Random jitter elimination from high speed links using Kalman filtering

Abstract

In this paper, a new and simple approach is presented to remove random jitter and intersymbol interference (ISI) effects from NRZ (Non-Return-to-Zero) signals. The method presented uses a Kalman filter to predict and remove the random jitter noise and Intersymbol Interference (ISI). Random jitter is modeled as a Gaussian distribution, with jitter effects on both rise and fall times of the signal. The Kalman filter adapts based on the provided model and predicts the exact position of the rise and fall times of the clock signal and a look-up table, combined with the Kalman filter, predicts the exact level of the signal. Random jitter and ISI simulations in MATLAB are presented and the results obtained are highly promising. The method provides a new approach to remove jitter from high-speed links without the use of clock data recovery circuits, feedforward and feedback equalizers.