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 Jan 01 2021
Journal Name
International Journal Of Agricultural And Statistical Sciences
EFFICACY ASSESSMENT OF BLACK PEPPER AND CLOVE EXTRACTS AGAINST SUNFLOWER SEEDS BLACK ROT DISEASE CAUSED BY ASPERGILLUS SPP.
...Show More Authors

Scopus (4)
Scopus
Publication Date
Wed Mar 30 2016
Journal Name
College Of Islamic Sciences
Ibn Al Anbari grammatical inferences On   Abu Hatim al-Sijistani through his book Clarify the stay and start
...Show More Authors

Ibn al-Anbari, however, turned to Abu Hatim al-Sijistani in eleven places of his book ((clarify the endowment and start)). The study showed that the right and right was with the son of Anbari and that what went to Sistani saying uniqueness, and contrary to the vast majority of scientists. The study also showed that the science of grammar affects the endowment and initiation, as the study showed that the science of endowment and initiation is one of the important sciences of the Koran, which must be carefully received, researchers.

View Publication Preview PDF
Publication Date
Sun Jun 06 2010
Journal Name
Baghdad Science Journal
Preparation of Media for Growth and Isolation of Lactic Acid Bacteria by Using the Starch-Industry by- Products
...Show More Authors

By- products of corn starch industry were used to prepare media for propagation the lactic acid bacteria as a natural auxotroph. The by- products used were the corn steep water (S) and gluten extract (G) after a proper treatment to get them ready for media preparation. The results showed that it was possible to replace the peptone and meat extract by gluten extract in MRS medium. The growth was approximately similar to that obtained in standard MRS media. Corn steep water (S) was used as well and the growth enhanced by including Tween – 80 at 1% level. The later media named MZ, which was superior for growing standard and local strains and starters. The MZ medium modified by adding acetate and glacial acetic acid similarly to

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Mar 04 2023
Journal Name
Baghdad Science Journal
Nordhaus-Gaddum Type Relations on Open Support Independence Number of Some Path Related Graphs Under Addition and Multiplication
...Show More Authors

In this paper, Nordhaus-Gaddum type relations on open support independence number of some derived graphs of path related graphs under addition and multiplication are studied.

View Publication Preview PDF
Scopus Clarivate Crossref
Publication Date
Thu Mar 05 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of different acids surface treatments and thermocycling on shear bond strength of composite resin to feldspathic ceramic
...Show More Authors

Background: the aim of this study was to evaluate the effect of different surface acids treatments (37%phospjoric acid, 5%hydrofluoric acid, 1.23 acidulated phosphate fluoride) of feldspathic ceramic VITA 3D MASTER , and the effect of thermocycling on shear bond strength using a ceramic repair kit (ivoclar/vivadent). Material and Methods: sixty Nickel-Chromium metal base plates were prepared(9mm diameter,3mm depth) using lost wax technique, 2mm thick layer of ceramic(VITA 3D MASTER) fused to metal plates, all specimens were embedded in acrylic resin blocks except their examined surfaces and divided into 3 main groups 20 specimens each, Grp A: treatment with 37%phosphoric acid for 2 mins, Grp B: etching with 5% hydrofluoric acid for 2mins,

... Show More
View Publication Preview PDF
Publication Date
Sun Jul 23 2023
Journal Name
University Of Samarra
Synthesis, spectral characterization and thermal ‎study of complexes of ions of some metallic ‎elements with new cyclic ligands
...Show More Authors

The purpose of my thesis is to prepare four new ligands (L1-L4) that have been ‎used to prepare a series of metal complexes by reacting them with metal ions:‎ ‎ M=(Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) ‎ ‎ Where succinyl chloride was used as a raw material for the preparation of ‎bi-dented ligands (L1-L4) by reacting it with potassium thiocyanate as a first ‎step and then reacting with (2-aminobenzothiazole, Benzylamine, 4-‎aminoantipyrine, Sulfamethoxazole) respectively as a second step with the use ‎of dry acetone as a solvent, the chemical formula of the four ligands prepared in ‎succession:‎ N1,N4-bis(benzo[d]thiazol-2-ylcarbamothioyl)succinamide (L1)‎ N1,N4-bis(benzylcarbamothioyl)succinami

... Show More
Publication Date
Fri May 01 2015
Journal Name
Ieee Transactions On Microwave Theory And Techniques
On the Design of Gyroelectric Resonators and Circulators Using a Magnetically Biased 2-D Electron Gas (2-DEG)
...Show More Authors

View Publication
Scopus (3)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Tue Jan 01 2019
Journal Name
Association Of Arab Universities Journal Of Engineering Sciences
Experimental and numerical investigation on the behavior of reinforced reactive powder concrete two-way slabs under static load
...Show More Authors

This paper studied the behaviour of reinforced reactive powder concrete (RPC) two-way slabs under static load. The experimental program included testing three simply supported slabs of 1000 mm length, 1000 mm width, and 70 mm thickness. Tested specimens were of identical properties except their steel fibers volume ratio (0.5 %, 1 %, and 1.5 %). Static test results revealed that, increasing steel fibers volume ratio from 0.5% to 1% and from 1% to 1.5%, led to an increase in: first crack load by (32.2 % and 52.3 %), ultimate load by (36.1 % and 17.0 %), ultimate deflection by (33.6 % and 3.4 %), absorbed energy by (128 % and 20.2 %), and the ultimate strain by (1.1 % and 6.73 %). The stiffness and ductility of the specimens also increased. A

... Show More
View Publication
Publication Date
Thu May 31 2012
Journal Name
Al-khwarizmi Engineering Journal
An Experimental Study on the Effect of Shape and Location of Vortex Generators Ahead of a Heat Exchanger
...Show More Authors

An experimental study is carried out on the effect of vortex generators (Circular and square) on the flow and heat transfer at variable locations at (X = 0.5, 1.5, 2.5 cm) ahead of a heat exchanger with Reynolds number ranging from 62000< Re < 125000 and heat flux from 3000 ≤ q ≤ 8000 W/m2 .

In the experimental investigation, an apparatus is set up to measure the velocity and temperatures around the heat exchanger.                     

The results show that there is an effect for using vortex generators on heat transfer. Also, heat transfer depends on the shape and location. The circular is found t

... Show More
View Publication Preview PDF
Publication Date
Wed Sep 14 2016
Journal Name
Journal Of Baghdad College Of Dentistry
Mechanical Evaluation of Pure Titanium Dental Implants Coated with a Mixture of Nano Titanium Oxide and Nano Hydroxyapatite
...Show More Authors

Background: The type of dental implant surface is one of many factors that determine the success of implant restoration. This study aimed to study the effect of mixture of nano titanium oxide with nanohydroxyapatite coating of screw shaped CPTi dental implant on bond strength at bone implant interface by torque removal test related to two healing periods (2 and 6 weeks). Materials and methods: Dip coating process was performed to get an even coating layer on CPTi screws. X-ray diffraction (XRD) analysis and microscopical examination were performed on the coating surfaces of the CPTi. The tibia of 10 white New Zealand rabbits was chosen as implantation sites. The tibia of each rabbit received two screws, one was coated with mixture of nanoT

... Show More
View Publication Preview PDF
Crossref (5)
Crossref