Title :
Joint mitigation of nonlinearity and modulator imperfections in dual-band concurrent transmitter using neural networks
Author :
Rawat, Meenakshi ; Rawat, Karun ; Younes, M. ; Ghannouchi, F.
Author_Institution :
Dept. of Electr., iRadio Lab., Calgary, AB, Canada
Abstract :
Reported, for the first time is a predistortion scheme for a concurrent dual-band transmitter with a dual-band concurrent Doherty power amplifier in the presence of modulator I/Q imbalance and DC offsets. Inverse PA modelling for predistortion is achieved using real valued time delayed neural networks. The model has been validated for a 10 W GaN based dual-band concurrent Doherty power amplifier for wideband code division multiple access signals at 1960 and 3500 MHz, respectively, and an adjacent channel power ratio improvement of 18 dB is reported.
Keywords :
III-V semiconductors; code division multiple access; gallium compounds; millimetre wave power amplifiers; neural nets; radio transmitters; DC offset; concurrent dual-band transmitter; dual-band concurrent Doherty power amplifier; dual-band concurrent transmitter; frequency 1960 MHz to 3500 MHz; inverse PA modelling; modulator I-Q imbalance; modulator imperfection; neural network; noise figure 18 dB; nonlinearity joint mitigation; power 10 W; wideband code division multiple access signal;
Journal_Title :
Electronics Letters
DOI :
10.1049/el.2012.3671
