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
Wed Jul 01 2020
Journal Name
Iraqi Geological Journal
BIOSTRATIGRAPHY OF THE LATE CRETACEOUS/EARLY PALEOCENE SUCCESSIONS AT K.H 5\6 AND K.H 5\8 CORE INTERVAL, WESTERN DESERT OF IRAQ
...Show More Authors

The core interval at the K.H5\6 and K.H5\8 Wells in the West of Rutba provinces reveals a significant succession across the Late Cretaceous–Early Paleocene transition. The sampled interval encompasses a series of carbonates belonging to Digma Formation of Latest Cretaceous age, which underlies the Akashat Formtion of Danian age. Fifty-five species belonging to thirty-five genera were recognized. Based on the distribution of these species, eight biozones were distinguished, three biozones are recorded from the K.H 5\6 studied section and two biozones are documented from the K.H 5\8 studied section which refers to Late Maastrichtian age of Digma Formation. Five biozones are recorded from Akashat Formation in the K.H 5\6 studied section and

... Show More
View Publication
Crossref (2)
Crossref
Publication Date
Wed Sep 01 2021
Journal Name
Iraqi Journal Of Physics (ijp)
Study the Effect of Graphene on the Contact Angle, Water Absorption and Thermal Stability ( TGA ,DSC) for Blend (Epoxy & Repcoat ZR)
...Show More Authors

In this study, polymeric coating was developed by incorporating nano graphene in the polymer blend with applications to oil storage tanks. The oil storage tanks samples were brought from the oil Pipeline Company / Doura refinery in Baghdad. The coating polymer was formed with a blend (epoxy resin and repcoat ZR). The proportion of mixing the mixture was 3:1:1 epoxy resin 21.06 gm: repcoat ZR 10.53 gm: hardener 10.53 gm. The blend/graphene was prepared using in stui-polymerization method with different weight percentage 1, 3, 5, and 7 wt % added to blend. The resulting solution was put in a glass tube on a magnetic stirrer for one hour at a temperature of 40 °C. The result of contact angle and water absorption the best ratio of 3wt

... Show More
View Publication
Crossref (1)
Crossref
Publication Date
Mon Apr 23 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Investigate of the Ability of Cronobacter sakazakii Isolated from Clinical Samples of Children Under Two Years to Induce Swimming, Swarming and Biofilm
...Show More Authors

      The study included 200 samples were collected   from   children  under two   years included (50 samples from each of Cerebrospinal fluid, Blood, Stool and Urine) from, Central Children Hospital and Children's Protections Educational Hospital. Isolates bacterial were obtained cultural, microscopic and biochemical examination and diagnosed to the species by using vitek2 system. The results showed there were contamination in 6.5% of clinical samples. The diagnosed colonies which gave pink color on the MacConkey agar , golden yellow color on the Trypton Soy agar and green color on the Birillent Enterobacter sakazakii agar and gave  a probability of 99% in the vit

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jul 14 2022
Journal Name
Egyptian Journal Of Medical Human Genetics
A single-nucleotide polymorphism of IL12A gene (rs582537 A/C/G) and susceptibility to chronic hepatitis B virus infection among Iraqi patients
...Show More Authors

A case–control study (80 patients with chronic hepatitis B virus [HBV] infection and 96 controls) was performed to evaluate the association of an IL12A gene variant (rs582537 A/C/G) with HBV infection. Allele G showed a signifcantly lower frequency in patients compared to controls (31.2 vs. 46.9%; probability [p]=0.009; corrected p [pc]=0.027) and was associated with a lower risk of HBV infection (odds ratio [OR]=0.49; 95% confdence interval [CI]=0.29–0.83). A similar lower risk was associated with genotypes CG (17.5 vs. 29.2; OR=0.25; 95% CI=0.08–0.81; p=0.02) and GG (10.0 vs. 16.7; OR=0.25; 95% CI=0.07–0.91; p=0.036), but the pc value was not signifcant (0.12 and 0.126, respec‑ tively). Serum IL35 levels showed signifcant difere

... Show More
Publication Date
Mon Dec 28 2020
Journal Name
Journal Of The College Of Education For Women
The Conflict of Active Regional and International Powers over Nagorny Karabakh Region: وداد حسين خضير علي , و مهيمن عبد الحليم طه الوادي
...Show More Authors

      The current study is descriptive; it focuses on studying the contemporary geopolitical problem, and sectarian differences in Caucasus. Nagorno-Karabakh is considered an important disputed region nowadays. Many parties and states participated in this dispute, especially after the conflict had developed into an open war between Armenia and Azerbaijan. Thus, the study aims to examine the causes of the conflict in this region, analyze the international positions on this conflict, and find if Armenia was able to occupy this region. The methodology adopted by the researchers is the functional approach, and the theory of power analysis that Cohen created for analyzing all strengths that drove each of the parties t

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jun 08 2023
Journal Name
Iraqi Journal Of Laser
PDF Lab-On-a-Chip an integrated microfluidic device sensitive low-Cost, and Rapid with a syringe pump for Analysis of Ibuprofen
...Show More Authors

Abstract: Microfluidic devices present unique advantages for the development of efficient drug assay and screening. The microfluidic platforms might offer a more rapid and cost-effective alternative. Fluids are confined in devices that have a significant dimension on the micrometer scale. Due to this extreme confinement, the volumes used for drug assays are tiny (milliliters to femtoliters).

 In this research, a microfluidic chip consists of micro-channels carved on substrate materials built by using Acrylic (Polymethyl Methacrylate, PMMA) chip was designed using a Carbon Dioxide (CO2) laser machine. The CO2 parameters have influence on the width, depth, roughness of the chip. In order to have regular

... Show More
View Publication Preview PDF
Publication Date
Tue Jan 01 2019
Journal Name
Opcion, Año
The effect of the -Zahorik- model on acquiring grammatical concepts among students of the College of Administration and Economics/University of Baghdad
...Show More Authors

Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Comparison of protein — A with clumping factor, hemolysis and coagulase tests for identification of Staphylococci isolated from Nasal swabs of healthy carriers
...Show More Authors

Thirty nine (12.8%) isolates of Staphylococcus aureus were isolated from 304 healthy human (Nasal swabs). It was found that percentage of males that have S. aureus is more than female's percentage. These isolates (39) were tested with different tests. Twenty seven isolates (69.23 %) were positive for Staphylococcus protein —A (SPA) ,thirty seven ( 94.8 %) were positive for tube coagulase , thirty five ( 89.7 % ) were positive with clumping factor and thirty two ( 82.05 %) had 13 — hemolytic on blood agar. It was found that 100% of the isolates (39 isolates) were positive with one, two or three tests (tube coagulase, clumping factor and SPA).

View Publication Preview PDF
Publication Date
Wed Jul 02 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of different palatal vault shapes and woven glass fiber reinforcement on dimensional stability of high impact acrylic denture base [Part I]
...Show More Authors

Background: Change in palatal vault shape and Reinforcement of high impact acrylic denture base resin may in turn affect the dimensional accuracy of acrylic resin and affecting the fitness of the denture.This study evaluated tostudy the effect of fiber reinforcement for high-impact acrylic resin denture base with different palatal vault shapes on adaptation or gap space between the denture base and the stone cast and compare with non-fiber reinforcement and effect of palatal vault shapes on adaptation of non-reinforced and fiber reinforced high impact denture base acrylic resin Material and method: Three different palatal vault shapes were prepared on standard casts using CNC (computer numerical control) machine. 60 samples of heat polymeri

... Show More
View Publication Preview PDF
Publication Date
Thu Jul 20 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Histological and Biochemical Effect of Galangin Conjugated Gold Nanoparticles on the kidneys Damage Induced by Carbon Tetrachloride of Adult Male Albino Mice
...Show More Authors

This study aimed to determine histological and functional effects of Galangin (Gal) conjugated with Gold nanoparticles (AuNPs) on the Kidneys male albino mice treated with CCL4. Gold nanoparticles were prepared chemically by Turkevich Method. Characterizing of the prepared AuNPs and AuNPs+Gal was carried out using UV Spectrophotometry, X-Ray Diffraction (XRD) and particle size,. For the in vivo study, 42 adult male albino mice were used and randomly distributed into seven groups and experiment extended for 14 days, first group (G1) was control group without any treatment, (G2) group injected intra-peritoneal (i.p) with CCl4 once a week to the end of experiments, (G3)  injected with  AuNPs, (G4 and

... Show More
View Publication Preview PDF