Compensation of correlated autoregressive clock jitter in arrays of Analog-to-Digital Converters

TL;DR

This paper introduces a joint tracking and compensation method for correlated clock jitter in ADC arrays using a VAR(1) model and a Kalman smoother, significantly reducing jitter-induced distortion.

Contribution

It presents a novel joint modeling and compensation approach for correlated jitter in ADC arrays, improving over traditional independent noise models.

Findings

Kalman smoother effectively tracks correlated jitter in ADC arrays.

Simulation results show significant reduction in jitter-induced distortion.

Model captures both temporal and spatial correlations in jitter.

Abstract

In modern communication systems, the fidelity of analog-to-digital converters (ADCs) is limited by sampling clock jitter, i.e., small random timing deviations that undermine ideal sampling. Traditional scalar models often treat jitter as independent Gaussian noise, which makes it essentially untrackable, whereas real ADCs also exhibit temporally correlated (spectrally colored) imperfections. Moreover, spatial cross-correlations between channels in multiple-input multiple-output (MIMO) ADCs are commonly neglected. This paper addresses the joint tracking and compensation of random, cross-correlated timing errors in ADC arrays by modeling jitter as a coupled vector autoregressive process of order one (VAR(1)). We propose a pilot-tone-based Kalman smoother to track and compensate the jitter, and simulations demonstrate substantial reductions in jitter-induced distortion across diverse scenarios.