Digital Signal Processing

Samir Abd Elghafar ¹, Salaheldin M. Diab ², Bassiouny M. Sallam ³, S. El-Rabaie ⁴, Moawad I. Dessouky ⁵, Fathi E. Abd El-Samie ⁶

Affiliations
1 Jazan University, SA
2 Helwan University, Cairo, EG
3 Menoufia University, Menou, EG
4 Menoufia University, EG
5 Dept. Electronics and Electrical Communications, Menoufia University, EG
6 Menoufia University, Menouf, EG

Abstract

This paper presents a new implementation of Discrete Multi-Tone (DMT) systems based on the Discrete Wavelet Transform (DWT) and time-domain equalization to maximize the bit rate. The objective of the proposed DWT-DMT system is to make use of the sub-band decomposition property of the DWT to reduce the channel effects on the transmitted signals. The mathematical model of the Time-domain Equalizer (TEQ) utilized in this paper is presented. This equalizer is tested in the Fast Fourier Transform Discrete Multi-Tone (FFT-DMT) system, and in the proposed DWT-DMT system for comparison. Simulation experiments shows that the performance of the proposed DWT-DMT system with the TEQ filter bank is better than that of the FFT-DMT system with the TEQ filter bank over the eight standard Carrier Serving Area (CSA) loops. The results show that employing the TEQ filter bank in the proposed DWT-DMT system can achieve high bit rates ranging from 2.899 Mbps to 5.369 Mbps.

Keywords

DMT System, DWT, FFT, TEQ.

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Bidaa Mortada ¹, El-Sayed M. El-Rabaie ², Mohamad F. El-Kordy ³, Osama Zahran ³, Fathi E. Abd El-Samie ²

Affiliations
1 Al-Menofia University, EG
2 Menoufia University, EG
3 Menoufia University, Menouf, EG

Abstract

Intrinsic Raman spectroscopy (IRS) is a technique to correct turbidity-induced Raman spectral distortions, resulting in the intrinsic Raman spectrum that would be observed in the absence of scattering and absorption. In this paper, we develop a closed form expression relating the observed and intrinsic Raman spectra through diffuse reflectance using a numerical technique. Also, we study the dependence of this expression on sample size and elastic scattering anisotropy. We compare the behavior   at various turbidities, at various collection spot radii, for different sample sizes and for various values of elastic scattering anisotropy () to get best fitting with minimum error and to have an accurate relation between observed and intrinsic Raman spectra.

Keywords

Diffuse Reflectance (R_d), Observed Raman Spectrum (Ram_OBS), Elastic Scattering Anisotropy(g) and Intrinsic Raman Spectrum(Ram_int).

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Safaa Elgazar ¹, El-Dolil Sami ¹, Alaa M. Abbas ¹, Fathi E. Abd El-Samie ²

Affiliations
1 Menoufia University, Menouf, EG
2 Electronic Engineering, Menoufia University, Menouf, EG

Abstract

This paper presents a comparative study between the watermark encryption algorithms that are applied for audio signals. The chaotic Baker map and DES with its four modes are used as watermark encryption algorithms. Encrypted watermark is embedded in audio signal using both SVD and block based SVD methods. Experimental results show that the OFB mode is the least sensitive to attacks compared with the chaotic Baker map.

Keywords

SVD, OFB, Signal-to-Noise Ratio.

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Eman A.Elshehaly ¹, Ibrahim M. Eldokany ¹, Sami A. El-Dolil ¹, Fathi E. Abd El-Samie ¹

Affiliations
1 Menoufia University, Menouf, EG

Abstract

This paper presents a speech enhancement approach using Wiener filter and wavelet transform techniques, optimized to deal with real-world noisy speech. The developed hybrid approach is tested for performance evaluation in terms of improvement in estimated Signal-to-Noise Ratio (SNR) and other objective quality measures for enhanced speech.

Keywords

Wavelet Transform, SNR, DWT.

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