Open Access

Modeling Nonlinear Power Amplifiers in OFDM Systems from Subsampled Data: A Comparative Study Using Real Measurements

  • Ignacio Santamaría1Email author,
  • Jesús Ibáñez1,
  • Marcelino Lázaro1,
  • Carlos Pantaleón1 and
  • Luis Vielva1
EURASIP Journal on Advances in Signal Processing20032003:726748

DOI: 10.1155/S1110865703306067

Received: 19 April 2002

Published: 20 November 2003

Abstract

A comparative study among several nonlinear high-power amplifier (HPA) models using real measurements is carried out. The analysis is focused on specific models for wideband OFDM signals, which are known to be very sensitive to nonlinear distortion. Moreover, unlike conventional techniques, which typically use a single-tone test signal and power measurements, in this study the models are fitted using subsampled time-domain data. The in-band and out-of-band (spectral regrowth) performances of the following models are evaluated and compared: Saleh's model, envelope polynomial model (EPM), Volterra model, the multilayer perceptron (MLP) model, and the smoothed piecewise-linear (SPWL) model. The study shows that the SPWL model provides the best in-band characterization of the HPA. On the other hand, the Volterra model provides a good trade-off between model complexity (number of parameters) and performance.

Keywords

nonlinear modeling high-power amplifiers OFDM signals subsampling techniques

Authors’ Affiliations

(1)
Communications Engineering Department (DICOM), University of Cantabria

Copyright

© Copyright © 2003 Hindawi Publishing Corporation 2003