Abstract

Imperfections in quadrature modulators (QMs), such as inphase and quadrature (IQ) imbalance, can severely impact the performance of power amplifier (PA) linearization systems, in particular in adaptive digital predistorters (PDs). In this paper, we first analyze the effect of IQ imbalance on the performance of a memory orthogonal polynomials predistorter (MOP PD), and then we propose a new adaptive algorithm to estimate and compensate the unknown IQ imbalance in QM. Unlike previous compensation techniques, the proposed method was capable of online IQ imbalance compensation with faster convergence, and no special calibration or training signals were needed. The effectiveness of the proposed IQ imbalance compensator was validated by simulations. The results clearly show the performance of the MOP PD to be enhanced significantly by adding the proposed IQ imbalance compensator.

Details

Title
New Adaptive Method for IQ Imbalance Compensation of Quadrature Modulators in Predistortion Systems
Author
Zareian, Hassan; Vahid Tabataba Vakili
Publication year
2009
Publication date
2009
Publisher
Springer Nature B.V.
ISSN
16876172
e-ISSN
16876180
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
855545499
Copyright
Copyright © 2009 Hassan Zareian et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.