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Performances of Spectral-Amplitude-Coding Optical CDMA systems
2011 13th International Conference on Transparent Optical Networks, 2011This paper presents the Spectral Amplitude Coding Optical Code Division Multiple Access (SAC-OCDMA) system using Super-imposed Fiber Bragg Grating (S-FBG) with balanced detection. We consider five unipolar families codes, namely the m-sequences, the perfect difference codes, the Balanced Incomplete Block Design (BIBD) codes, the Modified Quadratic ...
Amel Farhat, Mourad Menif, Houria Rezig
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Spectral amplitude coding OCDMA using AND subtraction technique
2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, 2007A new detection scheme, namely AND subtraction technique is proposed and presented in this paper. The theory is being elaborated and the calculated and simulation results have been done by comparing AND subtraction technique against complementary subtraction technique by using DW code.
S.A. Aljunid +5 more
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Security performance of spectral amplitude coding OCDMA systems
2008 International Conference on Electronic Design, 2008This paper presents the security performance of spectral amplitude code OCDMA systems. We examine factors affecting data security such as system capacity and its influences on the eavesdropper SNR. The eavesdropper probability of error-free code detection for Modified Double Weight (MDW) OCDMA scheme is investigated.
Hesham A. Bakarman +2 more
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The Evolution of Double Weight Codes Family in Spectral Amplitude Coding OCDMA
2014This paper presents the review of Double Weight (DW) codes family from perspective of codes evolution since beginning until now. First generation focuses on one-dimensional (1D) code which spreading has been carried out in time. Later, the second generation was introduced known as two-dimensional (2D) code where the encoding of data bit has spread in ...
N. Din Keraf +3 more
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New code for spectral-amplitude coding optical code-division multiple-access systems
International Conference on Electrical, Control and Computer Engineering 2011 (InECCE), 2011In this paper we present a novel code family for SAC-OCDMA system. The new code technique is called Dynamic Cyclic Shift (DCS) code. Which more flexible in selection the code length with variable cross correlation. Furthermore, incase of increasing the number of users there is no need to increase the weight value.
Thanaa H. Abd +4 more
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NLOS UV Communications Using M-ary Spectral-Amplitude-Coding
IEEE Transactions on Communications, 2013We present an M-ary spectral amplitude code (SAC) modulation technique to improve the performance of free-space optical (FSO) communication systems. Although this approach can be used in any dispersive FSO system, in this paper we focus on non-line of sight (NLOS) ultraviolet (UV) systems relying on atmospheric scattering.
Mohammad Noshad +2 more
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DPCM coding of spectral amplitudes without positive slope overload
IEEE Transactions on Signal Processing, 1991The author considers the problem of coding the spectral amplitudes of a sinusoidal transform coding (STC) vocoder operating at 2400 b/s, which was previously considered by R.J. McAulay and T.F. Quatieri (1987). Differential pulse code modulation (DPCM) coding of spectral amplitudes in vocoders can cause formant clipping because of positive slope ...
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Spectral amplitude warping (SAW) for noise spectrum shaping in audio coding
1997 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2002In this paper, we present a new approach to shape the coding noise in speech and audio coders. The approach, called spectral amplitude warping (SAW), consists essentially of a pre- and post-processing which apply a nonlinear transformation to the signal short-term spectrum prior to, and after, encoding.
Roch Lefebvre, Claude Laflamme
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New Code Structure for Enhanced Double Weight (EDW) Code for Spectral Amplitude Coding OCDMA System
2009 International Conference on Future Computer and Communication, 2008This paper presents a new structure for spectral amplitude coding optical code division multiple access systems based on the enhanced double weight (EDW) code. The new structure is based on mathematical model and step sequences. The reconstruction is carried for higher weighted code to build the code matrix by rules which will make high level weight ...
Ali Z. Zahid +2 more
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A New Optical Spectral Amplitude Coding Sequence: Khazani-Syed (KS) Code
2007 International Conference on Information and Communication Technology, 2007Optical transmission technologies are known to provide very high speed data rate. This includes the popular multi-channel dense wavelength division multiplexing (DWDM) technology which allows a straight forward transmission bandwidth enhancement by increasing the number of channels.This, however, will no longer be enough in the near future when the ...
M.K. Abdullah +4 more
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