Preferred Language
Articles
/
joe-1095
Pilot Based Channel Estimation and Synchronization in OFDM System
...Show More Authors

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.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Dec 30 2022
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Comparison of Estimation Sonic Shear Wave Time Using Empirical Correlations and Artificial Neural Network
...Show More Authors

Wellbore instability and sand production onset modeling are very affected by Sonic Shear Wave Time (SSW). In any field, SSW is not available for all wells due to the high cost of measuring. Many authors developed empirical correlations using information from selected worldwide fields for SSW prediction. Recently, researchers have used different Artificial Intelligence methods for estimating SSW. Three existing empirical correlations of Carroll, Freund, and Brocher are used to estimate SSW in this paper, while a fourth new empirical correlation is established. For comparing with the empirical correlation results, another study's Artificial Neural Network (ANN) was used. The same data t

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sat Jun 20 2020
Journal Name
International Journal Of Pharmaceutical Research
Synthesis , Physicochemical Studies and biological estimation of new mixed ligand complexes from hetrocyclic compounds
...Show More Authors

The purpose of this research is to synthesize a new mixed ligand Schiff base complexes of Co(II),Ni(II),Cu(II), Zn(II), Cd(II), and Hg(II),which are formulated from the Schiff base (L) that resulted from orthophathalaldehyde (2-PA) with 4-chloroaniline(4-NA). Diagnosis of prepared Ligand and its complexes is done by spectral methods as 1H–NMR, mass spectrometer, FTIR, UV-Vis, molar conductance, elemental microanalyses, atomic absoption and magnetic susceptibility. The analytical studyofall new complexes has shown octahedral geometries. Organic performance study of ligand Schiff base and its complexes reveals different activities agansit four types of bactria; two gram (+) and two gram (-) .

Publication Date
Wed Aug 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Comparison Some Estimation Methods Of GM(1,1) Model With Missing Data and Practical Application
...Show More Authors

This paper presents a grey model GM(1,1) of the first rank and a variable one and is the basis of the grey system theory , This research dealt  properties of grey model and a set of methods to estimate parameters of the grey model GM(1,1)  is the least square Method (LS) , weighted least square method (WLS), total least square method (TLS) and gradient descent method  (DS). These methods were compared based on two types of standards: Mean square error (MSE), mean absolute percentage error (MAPE), and after comparison using simulation the best method was applied to real data represented by the rate of consumption of the two types of oils a Heavy fuel (HFO) and diesel fuel (D.O) and has been applied several tests to

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Mar 30 2021
Journal Name
Journal Of Economics And Administrative Sciences
Some Estimation for the Parameters and Hazard Function of Kummer Beta Generalized Normal Distribution
...Show More Authors

Transforming the common normal distribution through the generated Kummer Beta model to the Kummer Beta Generalized Normal Distribution (KBGND) had been achieved. Then, estimating the distribution parameters and hazard function using the MLE method, and improving these estimations by employing the genetic algorithm. Simulation is used by assuming a number of models and different sample sizes. The main finding was that the common maximum likelihood (MLE) method is the best in estimating the parameters of the Kummer Beta Generalized Normal Distribution (KBGND) compared to the common maximum likelihood according to Mean Squares Error (MSE) and Mean squares Error Integral (IMSE) criteria in estimating the hazard function. While the pr

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Dec 30 2015
Journal Name
College Of Islamic Sciences
Estimation of the names and verbs of some letters to consider the grammatical industry
...Show More Authors

Estimation of the names and verbs of some letters to consider the grammatical industry

View Publication Preview PDF
Publication Date
Tue Sep 15 2020
Journal Name
International Journal Of Energy Research
Effect of airflow channel arrangement on the discharge of a composite metal foam‐phase change material heat exchanger
...Show More Authors

View Publication
Scopus (45)
Crossref (41)
Scopus Clarivate Crossref
Publication Date
Fri Mar 30 2007
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Drop Interface Coalescence in Liquid-Liquid System
...Show More Authors

This investigation is a study of the length of time where drops can exist at an oil-water interface before coalescence take place with a bulk of the same phase as the drops. Many factors affecting the time of coalescence were studied in is investigation which included: dispersed phase flow rate, continuous phase height, hole size in distributor, density difference between phases, and viscosity ratio of oil/water systems, employing three liquid/liquid systems; kerosene/water, gasoil/water, and hexane/water. Higher value of coalescence time was 8.26 s at 0.7ml/ s flow rate, 30cm height and 7mm diameter of hole for gas oil/water system, and lower value was 0.5s at 0.3ml/s flow rate, 10 cm height and 3mm diameter of hole for  hexane

... Show More
View Publication Preview PDF
Publication Date
Sat Dec 30 2023
Journal Name
Al-kindy College Medical Journal
Health System in Iraq Post 2003 War
...Show More Authors

Background: War represents a major human crisis; it destroys communities and results in ingrained consequences for public health and well-being

Objective: We set this study to shed light on the public health status in Iraq after the successive wars, sanctions, sectarian conflicts, and terrorism, in light of certain health indicators.

Design: The primary source of data for this analysis comes from the Iraqi Ministry of Health, and The World Health Organization disease surveillance.

Results: Most of the morbidity indicators are high, even those that are relatively declining recently, are still higher than those repor

... Show More
View Publication Preview PDF
Scopus (16)
Crossref (11)
Scopus Crossref
Publication Date
Sat Jun 30 2018
Journal Name
Proceedings Of The International Conference On Intelligent Science And Technology
The nature of intelligent system in buildings
...Show More Authors

View Publication
Scopus (1)
Scopus Crossref
Publication Date
Thu Aug 01 2024
Journal Name
Al-kindy College Medical Journal
Automation of the Healthcare System in Iraq
...Show More Authors

In the last few years, following the relative stability of the political, economic, and security environments, Iraq has embarked on a transformation towards an ambitious program of automation across various sectors. However, this automation program faces numerous challenges, including significant investments in technology and training, addressing social impacts, and combating widespread illiteracy

View Publication Preview PDF
Scopus Crossref