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 …
The security environment for Northeast Asia is extremely important, as it includes most of the international actors (United States of America, China, Russian Federation and Japan), which gives the nature of the interactions of these forces a special importance for the region.
Because of the multiplicity of policies and interests of the active forces in the region, the result has been an unstable regional environment where the interests of the major powers often clash repeatedly on many related issues, which is coupled with the growing efforts of many powers to adopt policies that differ from what they did in the past This resulted in different patterns of relations, which were mainly characterized by competition over regional lea
... Show MoreThis research sheds light on the physical environment role in creating the place attachment, by discussing one of the important factors in the attachment creation, it is the concept place dependence, consisting of two important dimensions: the place quality and the place expectation; they contain a number of the supporter physical environment sub-indicators for place attachment. Eight physical indicators were reached; they were found to have a close relationship to the place attachment, including: the open and green spaces existence, land use diversity, diversity of housing types, dwelling / population density, accessibility, transport network development degree, transport multiple mo
The polygamy as a social was known before Islam, has kept Islam on this system after it organized and put his controls and conditions, as justice between wives and the ability to alimony, it was not the purpose of satisfying the instinct of man and enjoyment, but his goal nominal than that, because it addresses problems humanity has goals noble, so the pluralism overlap of the fabric of families belonging to governance and benefits for women and men and society, which leads to increased ties of love between people of the same society and thus increases the cohesion and importance of the topic and its association with financial conditions have emerged as needed so you viewed in the second scientific Conference of the Department social Ser
... Show MoreThe harmonic oscillator (HO) and Gaussian (GS) wave functions within the binary cluster model (BCM) have been employ to investigate the ground state neutron, proton and matter densities as well as the elastic form factors of two- neutron 6He and 16C halo nuclei. The long tail is a property that is clearly revealed in the density of the neutrons since it is found in halo orbits. The existence of a long tail in the neutron density distributions of 6He and 16C indicating that these nuclei have a neutron halo structure. Moreover, the matter rms radii and the reaction cross section (𝜎𝑅 ) of these nuclei have been calculated using the Glauber model.
The aim of this research is to analyze the content of the science textbook for 7th grade Iraqi schools in the light of the educational concepts of sustainable development, the science textbook (1st edition), for the academic year 2017-2018. To this end, the researchers prepared list of issues in the light of the educational concepts of sustainable development, consisted of (13) issues, branched to (51) subissues, presented to a group of arbitrators and specialists in science curriculum and methods of teaching. The researchers analyzed the content of the 7th grade science textbook, in the light of the list that is built, the idea has been adopted as a unit of analysis. One of the most important findings is attention to neglected sub-issues o
... Show MoreIn this paper, we calculate and measure the SNR theoretically and experimental for digital full duplex optical communication systems for different ranges in free space, the system consists of transmitter and receiver in each side. The semiconductor laser (pointer) was used as a carrier wave in free space with the specification is 5mW power and 650nm wavelength. The type of optical detector was used a PIN with area 1mm2 and responsively 0.4A/W for this wavelength. The results show a high quality optical communication system for different range from (300-1300)m with different bit rat (60-140)kbit/sec is achieved with best values of the signal to noise ratio (SNR).
The real and imaginary part of complex dielectric constant for InAs(001) by adsorption of oxsagen atoms has been calculated, using numerical analysis method (non-linear least square fitting). As a result a mathematical model built-up and the final result show a fairly good agreement with other genuine published works.
In this work, chemical oxidation was used to polymerize conjugated polymer "Polypyrrole" at room temperature Graphene nanoparticles were added by in situ-polymerization to get (PPY-GN) nano. Optical and Electrical properties were studied for the nanocomposites. optical properties of the nanocomposites were studied by UV-Vis spectroscopy at wavelength range (200 -800 nm). The result showed optical absorption spectra were normally determined and the result showed that the maximum absorbance wave length at 280nm and 590nm. The optical energy gap has been evaluated by direct transition and the value has decreased from (2.1 eV for pure PPy) to (1.3 eV for 5 %wt. of GN). The optical constants such as the band tail width ΔE was evaluated, the
... Show More<span lang="EN-GB">Transmitting the highest capacity throughput over the longest possible distance without any regeneration stage is an important goal of any long-haul optical network system. Accordingly, Polarization-Multiplexed Quadrature Phase-Shift-Keying (PM-QPSK) was introduced lately to achieve high bit-rate with relatively high spectral efficiency. Unfortunately, the required broad bandwidth of PM-QPSK increases the linear and nonlinear impairments in the physical layer of the optical fiber network. Increased attention has been spent to compensate for these impairments in the last years. In this paper, Single Mode Fiber (SMF), single channel, PM-QPSK transceiver was simulated, with a mix of optical and electrical (Digi
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