Preferred Language
Articles
/
3xdlUpEBVTCNdQwC8pS3
Optical CDMA Coded STBC Based on Chaotic Technique in FSO Communication Systems
...Show More Authors

Free-Space Optical (FSO) can provide high-speed communications when the effect of turbulence is not serious. However, Space-Time-Block-Code (STBC) is a good candidate to mitigate this seriousness. This paper proposes a hybrid of an Optical Code Division Multiple Access (OCDMA) and STBC in FSO communication for last mile solutions, where access to remote areas is complicated. The main weakness effecting a FSO link is the atmospheric turbulence. The feasibility of employing STBC in OCDMA is to mitigate these effects. The current work evaluates the Bit-Error-Rate (BER) performance of OCDMA operating under the scintillation effect, where this effect can be described by the gamma-gamma model. The most obvious finding to emerge from the analysis is that the BER can be enhanced by orders of magnitude for different numbers of users and different values of scintillation effects using a MIMO

Scopus Crossref
View Publication
Publication Date
Thu Apr 29 2021
Journal Name
Egyptian Journal Of Chemistry
Fabrication and Study of ZnO thin Films using Thermal Evaporation Technique
...Show More Authors

Pure SnSe thin film and doped with S at different percentage (0,3,5,7)% were deposited from alloy by thermal evaporation technique on glass substrate at room temperature with 400±20nm thickness .The influences of S dopant ratio on characterization of SnSe thin film Nano crystalline was investigated by using Atomic force microscopy(AFM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), Hall Effect measurement, UV-Vis absorption spectroscopy to study morphological, structural, electrical and optical properties respectively .The XRD showed that all the films have polycrystalline in nature with orthorhombic structure, with preferred orientation along (111)plane .These films was manufactured of very fine crystalline size in the ra

... Show More
View Publication
Scopus (4)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Tue Sep 01 2020
Journal Name
Acta Polytechnica
COMPLEXITY REDUCTION OF CYCLOSTATIONARY SENSING TECHNIQUE USING IMPROVED HYBRID SENSING METHOD
...Show More Authors

In cognitive radio system, the spectrum sensing has a major challenge in needing a sensing method, which has a high detection capability with reduced complexity. In this paper, a low-cost hybrid spectrum sensing method with an optimized detection performance based on energy and cyclostationary detectors is proposed. The method is designed such that at high signal-to-noise ratio SNR values, energy detector is used alone to perform the detection. At low SNR values, cyclostationary detector with reduced complexity may be employed to support the accurate detection. The complexity reduction is done in two ways: through reducing the number of sensing samples used in the autocorrelation process in the time domain and through using the Slid

... Show More
View Publication
Scopus (8)
Crossref (6)
Scopus Clarivate Crossref
Publication Date
Tue Jun 01 2021
Journal Name
Periodicals Of Engineering And Natural Sciences
Steganography using dual tree complex wavelet transform with LSB indicator technique
...Show More Authors

Image steganography is undoubtedly significant in the field of secure multimedia communication. The undetectability and high payload capacity are two of the important characteristics of any form of steganography. In this paper, the level of image security is improved by combining the steganography and cryptography techniques in order to produce the secured image. The proposed method depends on using LSBs as an indicator for hiding encrypted bits in dual tree complex wavelet coefficient DT-CWT. The cover image is divided into non overlapping blocks of size (3*3). After that, a Key is produced by extracting the center pixel (pc) from each block to encrypt each character in the secret text. The cover image is converted using DT-CWT, then the p

... Show More
Preview PDF
Scopus (6)
Crossref (5)
Scopus Crossref
Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Engineering
Evaluation The Performance Geodetic of the Receivers Using Static Positioning Technique
...Show More Authors

Global Navigation Satellite System (GNSS) is considered to be one of the most crucial tools for different applications, i.e. transportation, geographic information systems, mobile satellite communications, and others. Without a doubt, the GNSS has been widely employed for different scientific applications, such as land surveying, mapping, and precise monitoring for huge structures, etc. Thus, an intense competitive has appeared between companies which produce geodetic GNSS hardware devices to meet all the requirements of GNSS communities. This study aims to assess the performance of different GNSS receivers to provide reliable positions. In this study, three different receivers, which are produced by different manufactur

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Engineering
Evaluation The Performance Geodetic of the Receivers Using Static Positioning Technique
...Show More Authors

Global Navigation Satellite System (GNSS) is considered to be one of the most crucial tools for different applications, i.e. transportation, geographic information systems, mobile satellite communications, and others. Without a doubt, the GNSS has been widely employed for different scientific applications, such as land surveying, mapping, and precise monitoring for huge structures, etc. Thus, an intense competitive has appeared between companies which produce geodetic GNSS hardware devices to meet all the requirements of GNSS communities. This study aims to assess the performance of different GNSS receivers to provide reliable positions. In this study, three different receivers, which are produced by different manufacturers, were fi

... Show More
View Publication
Crossref
Publication Date
Sat Oct 01 2011
Journal Name
Journal Of Engineering
IMPLEMENTATION OF GYPSEOUS SOIL-ASPHALT STABILIZATION TECHNIQUE FOR BASE COURSE CONSTRUCTION
...Show More Authors

The aim of this research work is to study the effect of stabilizing gypseous soil, which covers
vast areas in the middle, west and south parts of Iraq, using liquid asphalt on its strength properties
to be used as a base course layer replacing the traditional materials of coarse aggregate and broken
stones which are scarce at economical prices and hauling distances.
Gypseous soil brought from Al-Ramadi City, west of Iraq, with gypsum content of 66.65%,
medium curing cutback asphalt (MC-30), and hydrated lime are used in this study.
The conducted tests on untreated and treated gypseous soil with different percentages of medium
curing cutback asphalt (MC-30), water, and lime were: unconfined compression strength, and o

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Thu Nov 29 2018
Journal Name
Iraqi Journal Of Science
Application of WDR Technique with different Wavelet Codecs for Image Compression
...Show More Authors

FG Mohammed, HM Al-Dabbas, Iraqi journal of science, 2018 - Cited by 6

View Publication
Scopus (11)
Scopus
Publication Date
Wed Jan 01 2020
Journal Name
Ieee Access
Nondestructive Evaluation of Coatings Delamination Using Microwave Time Domain Reflectometry Technique
...Show More Authors

View Publication
Scopus (26)
Crossref (26)
Scopus Clarivate Crossref
Publication Date
Fri Apr 21 2023
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees22fr
Calculating the modes properties for glass optical fibers at He-Ne laser wavelength
...Show More Authors

View Publication
Scopus (3)
Crossref (1)
Scopus Crossref
Publication Date
Sat May 01 2021
Journal Name
Journal Of Physics: Conference Series
Design of Optical Fibers and Calculate their Guided Modes Properties at 1550 nm
...Show More Authors
Abstract<p>There is no doubt that optical fiber technology is one of the most important stages of the communications revolution at all and it is of utmost importance in our daily life. In this work, five fibers with core radii 2.5, 4.5 and 6.5–8.5 μm were designed. The properties of all guided modes have been calculated at a wavelength of 1550 nm by using RP Fiber Calculator. A single-mode fiber is obtained when the core radius approaches the wavelength. As the core radius is increased, the fiber becomes a multimode. The percentage power in the core increases with increasing core radius. The modes profiles were illustrated and compared with the modern references.</p>
View Publication
Scopus (6)
Crossref (2)
Scopus Crossref