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Downlink Training Design for FDD Massive MIMO Systems in the Presence of Colored Noise
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Massive multiple-input multiple-output (MaMi) systems have attracted much research attention during the last few years. This is because MaMi systems are able to achieve a remarkable improvement in data rate and thus meet the immensely ongoing traffic demands required by the future wireless networks. To date, the downlink training sequence (DTS) for the frequency division duplex (FDD) MaMi communications systems have been designed based on the idealistic assumption of white noise environments. However, it is essential and more practical to consider the colored noise environments when designing an efficient DTS for channel estimation. To this end, this paper proposes a new DTS design by exploring the joint use of spatial channel and noise covariance matrices, when the channel is not reciprocal but the coherence block length remains limited. We derive an analytical solution for the mean square error (MSE) based on the proposed training design with colored noise. In addition, this paper exploits the method of random matrix theory to provide an analytical solution for the downlink (DL) achievable sum rate of the regularized zero forcing beamforming (RZFBF) precoder. Numerical results demonstrate that using the proposed DTS design, the MSE of the channel estimate is significantly reduced compared with the conventional training designs with white noise. Furthermore, the results show that the proposed pilot design markedly improves the DL achievable SR over the conventional training designs, especially at relatively low signal-to-noise-ratio (SNR) levels. This enables FDD MaMi systems to operate under more practical scenarios of colored noise and limited coherence time environments.

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Publication Date
Fri Aug 20 2021
Journal Name
Iraqi Journal Of Laser
Design of Tunable Optical Band Pass Filter based on in-Line PM-Mach Zehnder Interferometer
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In this paper, tunable optical band-pass filters based on Polarization Maintaining Fiber –Mach Zehnder Interferometer presented. Tunability of the band-pass filter implemented by applying different mechanical forces N on the micro-cavities splicing regions (MCSRs). The micro-cavity formed by using three variable-lengths of single-mode polarization-maintaining fiber with (8, 16, 24) cm lengths, splice between two segments of (SMF-28) with (26, 13) cm lengths, using the fusion splicing technique.  Ellipsoidal shape micro-cavities experimentally achieved parallel to the propagation axis having dimensions between (12-24) μm of width and   (4-12) μm of length. A micro-cavity with width and length as high as 24 μm and 12 μ

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Publication Date
Tue Jan 30 2024
Journal Name
Iraqi Journal Of Science
Design and Feasibility Study of A Stand-Alone Home Pv Solar System in Baghdad Climate
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     The question asked by all researchers is when solar panels will replace the national grid, especially in the domestic sector. In this study, a rooftop stand-alone solar electric system is designed to provide all the electrical power to a house in Baghdad-Iraq, using a (How to design PV system) simulation program. The feasibility of this system compared to the performance of the national electric grid and the system of private diesel generators is determined. The proposed solar system capacity is (25 kW), and the space required and the energy payback time are (360 m2 and 7.82 years), respectively. By using the current system, the net CO2 mitigation amount is 499,518.2 tons for 30-year. The kilowatt-hour cost

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Publication Date
Fri Apr 01 2022
Journal Name
Separation And Purification Technology
Application of central composite design approach for optimisation of zinc removal from aqueous solution using a Flow-by fixed bed bioelectrochemical reactor
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Publication Date
Fri Apr 01 2022
Journal Name
Separation And Purification Technology
Application of central composite design approach for optimisation of zinc removal from aqueous solution using a Flow-by fixed bed bioelectrochemical reactor
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Publication Date
Wed Jan 15 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Micro CT analysis of amount of dentin removal created by SAF vs. ProTaper systems
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Background: Dentin removed during root canal system instrumentation for creating adequate geometry for the canal and cleaning the canal. A new instrument had been marketed with the aim of optimum shaping of all parts of the canal system, however, no information present about the amount of dentin removal compared to conventional rotary system. This study investigated the amount of dentin removal when the canal instrumented by SAF compared with ProTaper by using high resolution computed tomography (micro CT). Materials and Methods: Twenty extracted single canalled teeth were utilized for this study; and randomly divided into 2 groups. In the first group, the root canals were prepared by using protaper rotary system till F2 and the root canal

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Publication Date
Mon Dec 26 2011
Journal Name
Journal Of Intelligent Material Systems And Structures
Design and modeling magnetorheological directional control valve
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Directional control valves are designed to control direction of flow, while actuators maintain required speeds and precise positions. Magnetorheological (MR) fluid is a controllable fluid. Utilizing the MR fluid properties, direct interface between magnetic fields and fluid power is possible, without the need for mechanical moving parts like spools. This study proposes a design of a four-way three-position MR directional control valve, presents a method of building, and explains the working principle of the valve. An analysis of the design and finite elements using finite element method of magnetism (FEMM) software was performed on each valve. The magnetic circuit of the MR valve was analyzed and the performance was simulated. The

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Publication Date
Fri Sep 22 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Design Active Filter Based on Genetic Algorithm
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The  lossy-FDNR  based  aclive  fil ter has an  important   property among  many  design  realizations. 'This includes  a significant reduction in component count particularly in the number  of OP-AMP which consumes   power.  However  the·  problem  of  this   type  is the  large component spreads  which affect the fdter performance.

In  this  paper   Genetic   Algorithm   is  applied   to  minimize   the component  spread   (capacitance  and  resistance  p,read). The minimization of these spreads allow the fil

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Publication Date
Sat Jan 01 2022
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees21gr
Optical characteristics of simulated design of parabolic trough solar concentrator
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Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
design of cdte photoconductor detector and study of some electrical
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Been manufacturing detector Altosalih optical pattern contact metal semiconductor through deposition poles of aluminum metal on the chips of crystal cadmium Tleraad (CdTe) with directional [111] and growing with laboratory and annealed at a temperature 80c for 30 minutes and eat Study of some electrical properties nailed and scoutNmadj ??????? copper with non ??????? models to see effect Alichoab well research deals impact Alichoab and frequency detector resistance

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Publication Date
Sun May 10 2015
Journal Name
Al-academy
The industrial design aesthetic and its relationship with the recipient: باسم قاسم الغبان، صلاح نوري الجيلاوي
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The research problem lies in determining the beauty ranges between the receiver and the industrial product, The goal of the research, it is the definition of aesthetics in industrial design and its relation to the receiver, and the researcher outcome several conclusions of the, the most important was: 1. The role of accumulated experience, and their interaction with the vision of the artwork in achieving aesthetic perception and levels of artistic and aesthetic values and by the level of growth this taste of the recipient. 2. There are interactive and close relationship be the primary means for the integration of functional and aesthetic meaning the designer meant to get it to the receiver.

 

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