DocumentCode :
871935
Title :
Digital Predistortion for Envelope-Tracking Power Amplifiers Using Decomposed Piecewise Volterra Series
Author :
Zhu, Anding ; Draxler, Paul J. ; Hsia, Chin ; Brazil, Thomas J. ; Kimball, Donald F. ; Asbeck, Peter M.
Author_Institution :
Sch. of Electr., Univ. Coll. Dublin, Dublin
Volume :
56
Issue :
10
fYear :
2008
Firstpage :
2237
Lastpage :
2247
Abstract :
Due to dynamic changes of supply voltage, envelope-tracking (ET) power amplifiers (PAs) exhibit very distinct characteristics in different power regions. It is very difficult to compensate the distortion induced by these amplifiers by employing conventional digital predistortion techniques. In this paper, by introducing a new piecewise Volterra model based on a vector threshold decomposition technique, we first set several thresholds in the input power level according to the PA characteristics, and decompose the input complex envelope signal into several sub-signals by using these thresholds. We then process each sub-signal separately by employing the dynamic deviation reduction-based Volterra series, and finally recombine them together to produce the predistorted output. Experimental results show that by using this new decomposed piecewise digital predistorter model, the distinct characteristics of the ET system at different signal power levels can be accurately modeled, and thus, the distortion, including both static nonlinearities and memory effects, caused by the amplifier nonlinear behavior can be effectively compensated.
Keywords :
UHF power amplifiers; Volterra series; piecewise linear techniques; RF power amplifiers; amplifier nonlinear behavior; complex envelope signal decomposition; digital predistortion techniques; dynamic deviation reduction; envelope-tracking power amplifiers; frequency 2.14 GHz; memory effects; piecewise Volterra series; static nonlinearities; vector threshold decomposition technique; Behavioral modeling; Volterra series; envelope tracking (ET); linearization; power amplifier (PA); predistorter;
fLanguage :
English
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9480
Type :
jour
DOI :
10.1109/TMTT.2008.2003529
Filename :
4631463
Link To Document :
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