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joe-1095
Pilot Based Channel Estimation and Synchronization in OFDM System
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Channel estimation and synchronization are considered the most challenging issues in Orthogonal Frequency Division Multiplexing (OFDM) system. OFDM is highly affected by synchronization errors that cause reduction in subcarriers orthogonality, leading to significant performance degradation. The synchronization errors cause two issues: Symbol Time Offset (STO), which produces inter symbol interference (ISI) and Carrier Frequency Offset (CFO), which results in inter carrier interference (ICI). The aim of the research is to simulate Comb type pilot based channel estimation for OFDM system showing the effect of pilot numbers on the channel estimation performance and propose a modified estimation method for STO with less number of pilot to mitigate ISI effect. Channel estimation is simulated for different pilot number with 16QAM modulation in Ped-A Rayleigh channel. The STO effect assumed less than the cyclic prefix length to minimize ISI and maintain the orthogonality between subcarriers. The simulation results show that the high number of pilots are needed to achieve good channel estimation in case no synchronization used while similar results are achieved with smaller number of pilots if the propose modification on the synchronization method are used aligned with the channel estimation. The proposed system is evaluated in terms of BER and SNR.

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Publication Date
Tue Mar 31 2020
Journal Name
College Of Islamic Sciences
The benefits extracted from Surah of Prophet Mohammed ( peace upon him and on his family) from the beginning of Surah until the end of Ayah 15/ the 1st part
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The current study is concerned  over the  benefits  from  our Prophet  ' Surah , these   benefits  are seven  which are : the first : (  The  losing  , disappointment ,  weakness  in the affairs  of those disbelievers ,the second : showing the affairs of the believers   in respect to integrity ,  forgiveness   and rest, the third :  Indicating  the big difference  between the believers and disbelievers , each team has   his own characteristics that being distinguished from the other,  I have explained  the benefit   that the disbelievers are in a difficult

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Publication Date
Wed Jan 01 2025
Journal Name
Modern Sport
The Effect of Using an Electronic Program with Supplementary Tools on the Development of Futsal Officiating Performance Among Female Students of the College of Physical Education and Sport Sciences
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Due to the numerous motor and performance skills required of female students in futsal refereeing during college lessons, along with the constant need to reposition themselves and move within the playing field, continuous monitoring and repetition are essential to minimize potential errors during performance. These errors may arise from failing to assume the correct position or delays in signalling officiating gestures. Addressing this issue necessitated the implementation of an electronic program and supplementary tools—such as electronic games, scientific posters illustrating officiating signals, and other instructional aids—since these serve as guiding tools that direct individuals toward correct performance by distinguishing

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Publication Date
Fri Sep 20 2024
Journal Name
Journal Of Nano Research
Impact of Copper Doping on Nanocrystalline SnO<sub>2</sub> Thin Films Synthesized by Sol-Gel Coating and Chemical Bath Deposition for Gas Sensor Applications
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This work focuses on the preparation of pure nanocrystalline SnO2 and SnO2:Cu thin films on cleaned glass substrates utilizing a sol-gel spin coating and chemical bath deposition (CBD) procedures. The primary aim of this study is to investigate the possible use of these thin films in the context of gas sensor applications. The films underwent annealing in an air environment at a temperature of 500 C for duration of 60 minutes. The thickness of the film that was deposited may be estimated to be around 300 nm. The investigation included an examination of the structural, optical, electrical, and sensing characteristics, which were explored across various preparation circumstances, specifically focusing on varied

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Publication Date
Tue Jun 01 2021
Journal Name
Baghdad Science Journal
Comparing Weibull Stress – Strength Reliability Bayesian Estimators for Singly Type II Censored Data under Different loss Functions
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     The stress(Y) – strength(X) model reliability Bayesian estimation which defines life of a component with strength X and stress Y (the component fails if and only if at any time the applied stress is greater than its strength) has been studied, then the reliability; R=P(Y<X), can be considered as a measure of the component performance. In this paper, a Bayesian analysis has been considered for R when the two variables X and Y are independent Weibull random variables with common parameter α in order to study the effect of each of the two different scale parameters β and λ; respectively, using three different [weighted, quadratic and entropy] loss functions under two different prior functions [Gamma and extension of Jeffery

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Publication Date
Fri Apr 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
التنبؤ بقيم السلاسل الزمنية بأستعمال أنموذج (ARMAX) مع تطبيق عملي
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Abstract :

          Researchers have great interest in studying the black box models this thesis has been focused in the study one of the black box models , a ARMAX model which is one of the important models and can be accessed through a number of special cases which models (AR , MA , ARMA, ARX) , which combines method of the time series that depend on historical data and and regression method as explanatory variables addition to that past errors , ARMAX model importance has appeared in many areas of application that direct contact with our daily lives , it consists of constructing ARMAX model several traditional stages of the process , a iden

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Publication Date
Fri Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
Measuring the speed of response of the exported quantity of crude oil to the increase in its prices using the model Impulse Response Functions (IRF) (Iraq case study) for the period (1978-2017)
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Abstract

     Oil is considered a commodity and is still an important and prominent role in drawing and shaping the Iraqi economic scene. The revenues generated from the export of oil are considered the main source of the general budget in cash flows.  

     Since the revenues consist of quantity and price and the latter is an external factor which is difficult to predict, The effect of any commodity on its price, which is proven in the theory of micro-economic, but it is observed through the research that the response is slow, which means not to take advantage of the rise in prices, by increasing the quantity exported, the result of several facto

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Publication Date
Wed Jun 17 2026
Journal Name
Al–bahith Al–a'alami
Graduate Media Students’ Satisfaction Level in Their Program of Study:  The level of Satisfaction about the Study Programs of the masters of Media students / Case Study of Media faculties’ students at “Yarmouk University,
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The current study is considered a field study to measure the level of satisfaction of the academic programs of Media Masters students. That was accomplished through surveying the attitudes of the students who are enrolled in the faculties of media at the following universities: (Petra University, The Middle East University (MEU), and Al-Yarmouk University). Those students were enrolled in the master’s program within the formal educational system during the second semester of the academic year (2015 – 2016). This survey aims to identify the services, facilities and academic programs provided by the concerned faculties. It, also, aims to identify the public relations, administrative, educational and services aspects of those faculties.

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Publication Date
Tue May 16 2023
Journal Name
Political Sciences Journal
The Impact of Putinism on the Russian-Ukrainian Conflict: an analysis of the contents of the speeches of Russian President Vladimir Putin on the causes of the Russian war on Ukraine in 2022
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this research seeks to shed light on the study of the impact of Putinism on the Russian-Ukrainian war that broke out in early 2022, by studying the contents of the speeches of Russian President Vladimir Putin before the start of the war. This research uses the structural approach in analyzing the components of the Russian political regime. The research tools used in this research include case studies, content analysis of Russian speeches, and personal meetings of researchers and specialists in Russian affairs. It sums up a number of important conclusions, most notably are : 1) Putinism is a totalitarian regime that includes the political doctrine during the era of Russian President Vladimir Putin. 2) Duginism represents the totality of t

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Publication Date
Mon Jan 01 2018
Journal Name
International Journal Of Science And Research (ijsr)
Optimal Economic Design of Diversion Structures during Construction of a Dam by Particle Swarm Optimization
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Diverting river flow during construction of a main dam involves the construction of cofferdams, and tunnels, channels or other temporary passages. Diversion channels are commonly used in wide valleys where the high flow makes tunnels or culverts uneconomic. The diversion works must form part of the overall project design since it will have a major impact on its cost, as well as on the design, construction program and overall cost of the permanent works. Construction costs contain of excavation, lining of the channel, and construction of upstream and downstream cofferdams. The optimization model was applied to obtain optimalchannel cross section, height of upstream cofferdam, and height of downstream cofferdamwith minimum construction cost

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Publication Date
Thu Dec 28 2023
Journal Name
Journal Of Physical Education
The effect of preventive exercises using the (isometric) method and aids to help develop the strength of the thigh muscles of the first-class referees of the Iraqi Premier League
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The aim of the research is to identify the values of the level of muscular strength of the thighs, as well as to identify the significance of the differences between the pre-tests and the post-tests for the first-class football referees in the Iraqi Premier League. The researchers used the one-group experimental approach for its suitability to the nature of the study problem, and the research sample was from first-class referees in the Iraqi Premier League for the sports season (2022/2023), and their number was (15) referees. They took the comprehensive enumeration method, and special tests were conducted on them in the stadium and the private hall at the Ministry of Youth and Sports Center. After analyzing and discussing the result

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