Title :
A transmitter architecture for nonconstant envelope modulation
Author :
Berland, C. ; Hibon, I. ; Bercher, J.-F. ; Villegas, M. ; Belot, D. ; Pache, D. ; Le Goascoz, V.
Author_Institution :
ESYCOM-ESIEE laboratoire systeme de communication, Noisy-Le-Grand
Abstract :
This paper presents a transmitter architecture which is less sensitive to power amplifier AM/AM and AM/PM conversions. Indeed, most radio communication standards employ nonconstant envelope modulation such as in the 802.11 series. Owing to power amplifiers´ nonlinearities, distortions on the modulations degrade the overall transmitter performance. As a consequence, linearization methods, such as envelope elimination and restoration, have to be employed. The architecture relies on the transformation of a nonconstant envelope modulation to a constant or switched one. This signal coding enables the efficient amplification of the signal without undergoing power amplifier distortions. The envelope variation is restored by bandpass filtering just after the power amplifier
Keywords :
band-pass filters; linearisation techniques; modulation; power amplifiers; radio transmitters; radiocommunication; telecommunication standards; AM/AM conversions; AM/PM conversions; bandpass filtering; envelope elimination; envelope restoration; linearization techniques; nonconstant envelope modulation; power amplifiers; radio communication standards; signal coding; transmitter architecture; Band pass filters; Degradation; Filtering; OFDM modulation; Power amplifiers; Pulse amplifiers; Pulse width modulation; Radio transmitters; Signal restoration; Space vector pulse width modulation; Linearization techniques; pulsewidth modulation (PWM); sigma–delta (; transceivers;
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
DOI :
10.1109/TCSII.2005.854594
