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Journal of Computer Networks and Communications
Volume 2011, Article ID 235259, 10 pages
http://dx.doi.org/10.1155/2011/235259
Research Article

A Novel Technique for Transmission of M-Ary Signal through Wireless Fading Channel Using Wavelet Denoising

1EEE Department, ADUST, Dhaka, Bangladesh
2WebSatMedia Pte. Ltd., Technopark, Singapore 469003
3School of Engineering and Computer Science, IUB, Dhaka, Bangladesh

Received 30 March 2011; Accepted 24 June 2011

Academic Editor: Youyun Xu

Copyright © 2011 Md. Zahangir Alam 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

The paper proposes a novel technique for reducing noise in M-ary signal transmission through wireless fading channel using wavelet denoising that play the key role. The paper also explains that the conventional threshold-based technique is not capable of denoising M-ary quadrature amplitude modulated (M-QAM) signals having multilevel wavelet coefficients through wireless fading channels. A detailed step by step wavelet decomposition and reconstruction processes are discussed here to transform a signal function into wavelet coefficients using simulation software like MATLAB. A 16-QAM modulated symbol through a Rician fading channel is weighted by a control variable of complex form to force the mean of each detail coefficient except low frequency component to zero to enhance noiseless property. The bit error rate (BER) performance of the simulation results are furnished to show the effectiveness of the proposed technique. The root mean square of the deviation of the reconstruct signal from the original signal is used to express the effectiveness of the proposed technique. The traditional denoising provides very high value (above 90%) of the percentage root mean square difference (PDR) and the proposed technique provides only 10% PDR value for the symbol through a noisy channel. The result of the simulation study reveals that the BER performance can be increased using an appropriate control variable to force the mean of each detail coefficient to zero.