Title :
A highly efficient adaptive digital predistortion amplifier for IMT-2000 base stations
Author :
Kubo, Tokuro ; Fudaba, Nobukazu ; Ishikawa, Hiroyoshi ; Hamada, Hajime ; Nagatani, Kazuo ; Hayashi, Hiroyuki ; Maniwa, Toru ; Oishi, Yasuyuki
Author_Institution :
Mobile Commun. Dev. Laboratories, Fujitsu Labs. Ltd., Kanagawa, Japan
Abstract :
We have developed the world´s most compact, energy-efficient transmitter amplifier for IMT-2000 base station systems that uses an adaptive digital predistorter (DPD). The power efficiency is improved by reducing the output back-off (the margin from the saturation point) of power amplifiers and by suppressing the resulting increase in nonlinear distortion with the DPD. This method uses a predistortion technique that estimates the distortion characteristics of amplifiers by using the least mean square (LMS) algorithm, and it adds a complementary signal to the digital baseband signal with a reverse-characteristic of the distortion. The power amplifiers we have developed achieve twice the power efficiency of conventional types. In this paper, we describe the DPD equipment and the experimental results of a DPD transmitter prototype. Currently, IMT-2000 base station systems equipped with the DPD are being shipped worldwide.
Keywords :
3G mobile communication; interference suppression; least mean squares methods; nonlinear distortion; power amplifiers; radio transmitters; transceivers; IMT-2000 base station systems; adaptive digital predistorter; adaptive digital predistortion amplifier; base transceiver stations; least mean square algorithm; nonlinear distortion; power efficiency; Base stations; Baseband; Delay lines; Energy consumption; Laboratories; Multiaccess communication; Nonlinear distortion; Power amplifiers; Predistortion; Transmitters;
Conference_Titel :
Vehicular Technology Conference, 2003. VTC 2003-Spring. The 57th IEEE Semiannual
Print_ISBN :
0-7803-7757-5
DOI :
10.1109/VETECS.2003.1208780
