Table of Contents
ISRN Signal Processing
Volume 2011, Article ID 683972, 7 pages
http://dx.doi.org/10.5402/2011/683972
Research Article

Decoding of Turbo Codes in Symmetric Alpha-Stable Noise

1Faculty of Engineering, Multimedia University, Jalan Multimedia, 63100 Cyberjaya, Selangor, Malaysia
2Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB, Canada R3T 5V6
3Faculty of Engineering & Technology, Multimedia University, Jalan Ayer Keroh Lama, 75450 Melaka, Malaysia

Received 7 December 2010; Accepted 27 January 2011

Academic Editors: A. Fernandez-Caballero and K. Sivakumar

Copyright © 2011 Mohammad Shafieipour et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This paper investigates the decoding of turbo codes in impulsive symmetric α-stable (SαS) noise. Due to the nonexistence of a closed-form expression for the probability density function (pdf) of α-stable processes, numerical-based SαS pdf is used to derive branch transition probability (btp) for the maximum a posteriori turbo decoder. Results show that in Gaussian noise, the turbo decoder achieves similar performance using both the conventional and the proposed btps, but in impulsive channels, the turbo decoder with the proposed btp substantially outperforms the turbo decoder utilizing the conventional btp. Results also confirm that the turbo decoder incorporating the proposed btp outperforms the existing Cauchy-based turbo decoder in non-Cauchy impulsive noise, while the two decoders accomplish similar performance in Cauchy noise.