Estimating PLL Phase Noise Parameters from Measurements for System-Level Modeling

TL;DR

This paper introduces a least squares method to estimate PLL phase noise parameters from measurements, enabling accurate system-level modeling for MIMO communication systems.

Contribution

It presents a novel LS estimation technique for PLL parameters based on measured spectra, applicable to real chips like MAX2870 and MAX2871.

Findings

Parameter estimates enable accurate time- and frequency-domain simulations

Method applied successfully to real PLL chips

Provides a practical approach for phase noise modeling in systems

Abstract

In current MIMO mobile communication systems, phase noise can significantly impair performance. To allow for compensation of these impairments, accurate phase noise modeling is necessary. Numerical modeling of the phase noise process at a phase-locked loop (PLL) output is established in the literature and commonly represented by an Ornstein-Uhlenbeck (OU) process. The corresponding spectrum can be represented by a multi-pole/zero model. This work presents a least squares (LS) method for estimating the PLL parameters such as oscillator constants or PLL bandwidth from a measured phase noise spectrum. The method is applied on the MAX2870 and MAX2871 PLL chips and parameter estimates such as oscillator constants and PLL bandwidths are provided. The resulting parameter set enables both time- and frequency-domain numerical simulations.