Preferred Language
Articles
/
1hdgUpEBVTCNdQwCQ5RF
Optical Power Distributions for 4×4 MIMO Visible Light Communications in Indoor Environment
...Show More Authors

Visible Light Communication (VLC) has emerged as a powerful technique for wireless communication systems. Providing high data rate and increasing capacity are the major problems in VLC. Recent evidence suggests that Multiple Input Multiple Output (MIMO) technique can offers improved data rates and increased link range. This paper describes the design and implementation of visible light communication system in indoor environment exploring the benefits of MIMO. The specific objective of this research was to implement a 4× 4 Multiple Input (LEDs) Multiple Output (photodetectors)-VLC communication system, where a 16 white power LEDs in four arrays are setting up at transmitter and four RX modules are setting up at receiver side without the need for additional power or bandwidth as well as analyze a mathematical model for a VLC-× 4 MIMO with different modes such as the suitable angles to cover the entire room. The research designs practically an electronic circuit for the transmitter and receiver with inexpensive components. The power distribution of different propagation modes is calculated for Single Input Single Output (SISO) and MIMO channels in typical room dimensions. The results in this paper indicate that the power is distributed uniformly for entire room when implemented VLC-MIMO as compared to VLC-SISO. Furthermore, a 4× 4 MIMO implementing VLC is compared in term of BER vs. SINR with SISO communication system for both Line of Sight (LOS) and Non Line of Sight (NLOS) propagation modes. Comparing the two results of LOS and NLOS, it can be seen that a 4× 4 MIMO implementing VLC for LOS perform better …

Scopus Crossref
View Publication
Publication Date
Sun Jun 07 2009
Journal Name
Baghdad Science Journal
Investigation of the Optical Properties of the Achromatic Quadrupole Lens by Using the Rectangular Potential Distribution Model
...Show More Authors

An optimization calculation is made to find the optimum properties of combined quadrupole lens which consists of electrostatic and magnetic lens. Both chromatic and spherical aberration coefficients are reduced to minimum values and the achromatic aberration is found for many cases. These calculations are achieved with the aid of transfer matrices method and using rectangular model of field distribution, where the path of charged-particles beam traversing the field has been determined by solving the trajectory equation of motion and then the optical properties for lens have been computed with the aid of the beam trajectory along the lens axis. The computations have been concentrated on determining the chromatic and spher

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue May 28 2024
Journal Name
Journal Of Optics
Study of the optical properties of aluminum films and the effect of current frequency on plasma parameters
...Show More Authors

View Publication
Scopus Clarivate Crossref
Publication Date
Thu Jan 15 2015
Journal Name
مجلة كلية التربية-المؤتمر العلمي التخصصي لكلية التربية
Investigation the Effect of Irradiation by Gamma-Ray on the Structural and Optical Properties of (CIGS) Films
...Show More Authors

Publication Date
Wed May 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Annealing Effect on the Optical Properties of (ZnO)x (CdO)1-x Films Obtained by Spray Pyrolysis
...Show More Authors

The effect of the annealing on the optical transmission , absorp tion coefficient,
dielectric constants (ε
r
),( ε
i
) ,Skin depth and the optical ener gy gap of (ZnO)x(CdO)1-x thin
films with (x=0.05) deposited on preheated glass substrates at a temperature of (450 C°) by
chemical pyrolysis technique were performed . These f ilms show direct allowed inter band
transition that influenced by annealing at ( 450 C°) for two hours . And it also found that the
optical ener gy gap has been increased fro m about (2.50 eV) before annealing to about (2.65
eV) after annealing , fro m the analysis of the absorp tion and transmission sp ectra in the
wavelength range (380-900nm) . The results show t

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 20 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Study Influence of Substrate Temperature on Optical Properties of CdS Thin Films Prepared by Chemical Spray pyrolysis
...Show More Authors

This study aims to prepare Cadmium Sulphide (CdS) thin films using thermal Chemical Spray Pyrolysis (CSP) on glass of different temperatures substrate from cadmium nitrate solution. Constant thickness was (430 ± 20 nm) and the effect of substrate temperature on the optical properties of prepared thin films.

Optical properties have been studied from transmittance and absorbance spectral within wavelengths range (360 - 900 nm). The results show that all the prepared films have a direct electron transitions and optical energy gap between (2.31-2.44 eV). They also show that the transmittance and optical energy gap of films prepared from nitrate solution increase with increasing of substrate temperature, then transmittance start do

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Tue May 02 2023
Journal Name
Journal Of Optoelectronics And Advanced Materials
Preparation of samarium doped-PMMA composite by casting method to evaluate the optical properties and potential applications
...Show More Authors

Samarium ions (Sm +3), a rare-earth element, have a significant optical emission within the visible spectrum. PMMA samples, mixed with different ratios of SmCl3.6H2O, were prepared via the casting method. The composite was tested using UV-visible, photoluminescence and thermogravimetric analysis (TGA). The FTIR spectrometry of PMMA samples showed some changes, including variation in band intensity, location, and width. Mixed with samarium decreases the intensity of the CO and CH2 stretching bands and band position. A new band appeared corresponding to ionic bonds between samarium cations with negative branches in the polymer. These variations indicate complex links between the Sm +3 ion and oxygen in the ether group. The optical absorption

... Show More
Publication Date
Thu Apr 27 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Thickness on Some Optical Properties of Fe2O3 Thin Films Prepared by Chemical Spray Pyrolysis Technique
...Show More Authors

  The paper reports the influence of the thickness on the some optical properties of Fe2O3 thin films,which were prepared by chemical Spray  pyrolysis technique on glass substrate heated to 400Ëšc.The thickness of thin films (250,280,350)nm were measured by using weighting method. The optical properties include the absorbance and reflectance spectra,extinction coefficient,and real and imaginary part of the dielectric constant.The result  showed that the optical constant(k,εr,εi)decreased with the increase of the thickness.

View Publication Preview PDF
Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
The Effect of annealing temperature on the optical properties of (Cu2S)100-x( SnS2 )x thin films
...Show More Authors

Thin films of (Cu2S)100-x( SnS2 )x at X=[ 30,40, &50)]% with thickness (0.9±0.03)µm , had been prepared by chemical spray pyrolysis method on glass substrates at 573 K. These films were then annealed under low pressure of(10-2) mbar ,373)423&473)K for one hour . This research includes , studying the the optical properties of (Cu2S)100-x-(SnS2)x at X=[ 30,40, &50)]% .Moreover studying the effect of annealing on their optical properties , in order to fabricate films with high stability and transmittance that can be used in solar cells. The transmittance and absorbance spectra had been recorded in the wavelength range (310 - 1100) nm in order to study the optical properties . It was found that these films had direct optical band

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Apr 24 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Influence of Gamma Radiation on Some Optical Properties and Urbach Energy of (PMMA- Doped Red Methyl) Films
...Show More Authors

  We have studied the effect of gamma irradiation on the optical transmission, absorbance, absorption coefficient,  and Urbach energy for (PMMA- doped red methyl) film deposited by using solvent casting method .The optical transmission (T %) in the wavelength range (1901100 ) nm of films was measured , it was seen that all the parameters were affected by gamma irradiation.

View Publication Preview PDF
Publication Date
Sun May 01 2011
Journal Name
Thin Solid Films
Effect of temperature and deposition time on the optical properties of chemically deposited nanostructure PbS thin films
...Show More Authors

View Publication
Scopus (56)
Crossref (52)
Scopus Clarivate Crossref