Title :
Neural network applications to satellite nonlinear channel processing
Author :
Abdulkader, H. ; Roviras, D. ; Castanie, F.
Author_Institution :
Dept. of Commun., Univ. of Aleppo, Syria
Abstract :
We investigate applications of neural networks for nonlinear processing of satellite channels. On-board a satellite, a high power amplifier HPA: a travelling wave tube TWT or a solid state power amplifier SSPA, is implemented. In order to get the maximum power efficiency of on-board power sources, the amplifier is designed to operate near the saturation. So it shows a nonlinear performance. Due to the nonlinear amplification, the amplified signal suffers from a complex distortion. A good model of this amplifier is a nonlinear complex gain which can be split to an amplitude nonlinearity, or AM/AM conversion, and a phase nonlinearity, or AM/PM conversion. We present a NN based predistortion scheme, in the baseband, and two methods for updating weights and bias of the predistorter.
Keywords :
channel estimation; distortion; equalisers; neural nets; power amplifiers; quadrature amplitude modulation; satellite communication; travelling wave tubes; TWT; equalization; neural networks; nonlinear high power amplifier; nonlinear satellite channels; on-board power sources; predistortion scheme; regenerative payload; satellite nonlinear channel processing; solid state power amplifier; travelling wave tube; Artificial satellites; Constellation diagram; Equalizers; High power amplifiers; Linearity; Neural networks; Nonlinear distortion; Payloads; Power amplifiers; Predistortion;
Conference_Titel :
Information and Communication Technologies: From Theory to Applications, 2004. Proceedings. 2004 International Conference on
Print_ISBN :
0-7803-8482-2
DOI :
10.1109/ICTTA.2004.1307658
