Premium
New estimation and compensation method for quadrature modulator and demodulator errors in digital predistortion system
Author(s) -
Zhan Peng,
Qin Kaiyu,
Cai Shunyan
Publication year - 2012
Publication title -
international journal of rf and microwave computer‐aided engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.335
H-Index - 39
eISSN - 1099-047X
pISSN - 1096-4290
DOI - 10.1002/mmce.20597
Subject(s) - predistortion , demodulation , compensation (psychology) , computer science , electronic engineering , quadrature (astronomy) , correctness , control theory (sociology) , quadrature amplitude modulation , compensation methods , bandwidth (computing) , telecommunications , engineering , algorithm , bit error rate , channel (broadcasting) , amplifier , artificial intelligence , psychology , control (management) , psychoanalysis , digital marketing , world wide web , return on marketing investment
This article proposes a new method to estimate and compensate for the in‐phase and quadrature (IQ) imbalance errors of the quadrature modulator (QM) and demodulator (QDM) without interrupting the transmission. It uses two groups of captured signals, which transmit through two feedback loops with different propagation delays, to separate and estimate the IQ imbalance errors. In comparison with the previous methods, the greatest advantage of the proposed method is that both compensators of the QM and QDM can be obtained without additional feedback loop, and then the digital predistorter can be designed without the disturbance of IQ imbalance errors. This method can improve the compensation performance of digital predistortion with lower costs and less complexity. Experimental results show the correctness and effectiveness of the proposed method. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.