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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
Sun Jun 02 2019
Journal Name
Baghdad Science Journal
Assessing of Some Toxic Heavy Metals Levels and Using Geo Accumulation Index in Sediment of Shatt Al-Arab and the Iraqi Marine Region
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Mercury, arsenic, cadmium and lead, were measured in sediment samples of river and marine environmental of Basra governorate in southern of Iraq. Sixteen sites of sediment were selected and distributed along Shatt Al-Arab River and the Iraqi marine environment. The samples were distributed among one station on Euphrates River before its confluence with Tigris River and Shatt Al-Arab formation, seven stations along Shatt Al-Arab River and eight stations were selected from the Iraqi marine region. All samples were collected from surface sediment in low tide time. ICP technique was used for the determination of mercury and arsenic for all samples, while cadmium and lead were measured for the same samples by using Atomic Absorption Spectrosc

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Publication Date
Sat May 23 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Caries severity in relation to oral health knowledge and behavior of third and fifth year dental students / University of Baghdad (A comparative study)
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Background: Tooth wear is one of the most common problems in the older dentate population which results from the interaction of three processes (attrition, abrasion and erosion) and it affects all societies, different age groups, and all cultures. This study was achieved to evaluate the prevalence and distribution of tooth wear among institutionalized residents in Baghdad city\ Iraq. Subjects and Methods: This survey was accomplished on four private and one governmental institution in Baghdad city. One-hundred twenty three (61 males, 62 females) aged 50-89 years were participated in this study. The diagnosis and recording of tooth wear were according to criteria of Smith and Knight. Results: The prevalence of tooth wear was 100% with a mean

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Publication Date
Tue Jan 01 2019
Journal Name
African Journal Of Hospitality, Tourism And Leisure
Employing marketing information systems for the success of small and medium enterprises: A field study of some Tourism and Travel companies in Baghdad
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Scopus (6)
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Publication Date
Sun Sep 06 2015
Journal Name
Baghdad Science Journal
Calculation of Radial Electron-Electron Distribution function and Expectation Values for Li-Atom in Excited States 1s 2p, 1s 3p and 1s 3d
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The electron correlation for inter-shells (1s 2p), (1s 3p) and (1s 3d) was described by the inter-particle radial distribution function f(r12). It was evaluated for Li-atom in the different excited states (1s2 2p), (1s2 3p) and (1s2 3d) using Hartree-Fock approximation (HF). The inter particle expectation values for these shells were also evaluated. The calculations were performed using Mathcad 14 program.

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Publication Date
Mon Jan 01 2018
Journal Name
Journal Of Biodiversity And Environmental Sciences (jbes)
Effect of potassium fertilization and organic nutrient (Reef Amirich) in the population density of Bemisia tabaci (Genn.) and Thrips tabaci (L.) on cucumber
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A field study was conducted at the college of Agriculture, Baghdad University-Jadiriyah to investigate the effect of adding potassium fertilizer and organic nutrient (Reef Amirich) on the population density of two sucking pests of cucumber, cotton whitefly, Bemisia tabaci and onion thrips, Thrips tabaci during the spring season/2016. Results indicated that potassium sulphate (50, 100 and 150 kg/ha) and organic nutrient (0.8 and 1.6ml/l) reduced both the population density of B. tabaci and T. tabaci nymphs depending on the fertilizer level of the user, the treatment 150 kg/ha for the potassium fertilizer and 1.6 ml/L for organic nutrient was the highest among others when minimized density of nymphs by 1.62 nymphs of B. tabaci/disk leaf and 0

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Publication Date
Sat May 23 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Immunohistochemical expression of D2-40, VEGF and PCNA as biological markers of lymphangiogenesis, angiogenesis and proliferation in pleomorphic adenoma of salivary gland origin
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Background: Pleomorphic adenoma is the most common benign salivary gland tumor and shows a pronounced morphological complexity and diversity; for this The immunoprofiles and clinical course of PA differed according to cellular differentiation. Therefore, it is important to assess potential biomarkers in diagnostic and therapeutic trials. This study evaluates the immunohistochemical expression of D2-40, VEGF and PCNA as markers of lymphangiogenesis, angiogenesis and proliferation of PA and their correlation with clinicpathological parameters and with each other. Materials and Methods: Twenty five formalin – fixed, paraffin – embedded tissue blocks were included in this study. After histopathological reassessment of haematoxylin & eosin

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Publication Date
Sat Mar 02 2019
Journal Name
Biochem. Cell.arch.
EVALUATION OF PRIMARY IMPLANTS STABILITY IN IMMEDIATE AND DELAYED TREATMENT PROTOCOLS ACCORDING TO BONE DENSITY, JAWS, GENDER AND AGE UTILIZING PERIOTEST M DEVICE
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Publication Date
Fri Jan 01 2021
Journal Name
Revista Iberoamericana De PsicologÍa Del Ejercicio Y El Deporte
SPECIAL EXERCISES IN THE HIERARCHICAL OPPOSING TRAINING METHOD AND ITS EFFECT ON DEVELOPING PHYSICAL ABILITIES AND ACCURACY OF SOCCER SCORING FOR ADVANCED PLAYERS
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Scopus
Publication Date
Sun Oct 10 2021
Journal Name
Journal Of Kirkuk University For Agricultural Sciences
Effect of Drought Stress (Water Deficit) and Plant Density on Productivity of Water and Zea mays (Baghdad Varieties) in Middle Region of Iraq
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The objective of this study was to investigate the drought stress and plant density possibility on water productivity and grain yield of maize (Zea mays L.) (Planting Baghdad 3 synthetic varieties), Field experiment was conducted at Abu Ghraib Research Station (Baghdad) during spring and Autumn seasons of 2016 using a randomized complete block design arranged in split plot with three replications. Three irrigation treatment included: irrigation after depletion 50% of available water (T1), irrigation after depletion 75% of available water (T2) and irrigation after depletion 90% of available water (T3) in the main plots and three plant density which were: 1 seeds hill-1 (D1) giving a uniform plant density of 66666 plants ha-1 , 2 seeds hill1

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Publication Date
Thu Mar 25 1993
Journal Name
كلية العلوم. / جامعة بغداد
ISOLATION AND CHARACTERIZATION OF EXTREMELY HALOPHILIC BACTERIA FROM SADDAM RIVER REGIONS AND THE RULE OF MEMBRANE PROTEINS IN THE RESISTANCE TO HIGH SALINITY
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This study included isolation and characterization of extremely halophilic bacteria from Al-Massab Al-Aam region in South of Iraq Fifty isolates were identified by using numerical taxonomy 40 strains belonged to the genus Halobacterium which inclucted Hb. halobium Hb. cutirubrum Hb. salinarium Hb. saccharovorum Hb. valismortis and Hb. volcanii. Ten strains belonged to the genus Halococcus which included Hc. morrhuae Hc. saccharolyticus. Growth curves were sensitive mutants determined for wild type and salt Generation time in logarthmic phase was measured and found to be (10.37 2hr 7 0.59) for Hb. salinarium / 18 (6.490 hr 0.24) for Hb. cutirubrum / 32, (6.700 hr + 0.488) for Hb. valismortis / 20, (11.243 hr + 0.96) for Hb. volcanii / 7. (7

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