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.
Background: Varicose vein (VV) is a common problem that mostly occurs in legs. This medical condition can influence the quality of life and working condition of nurses. Aim of the study: To estimate the prevalence of lower limbs varicosity and its associated risk factors among nurses. Methods: This a cross-sectional descriptive study was carried out among 100 nurses working Baghdad Teaching Hospital, Surgical Specialties Hospital, and Al- Kidney Teaching Hospital, Baghdad, Iraq from January 1st to May 10th, 2022. The participants were recruited in the study using systematic random sampling. The Occupational Sitting and Physical Activity and Aberdeen Varicose Vein Questionnaires were used for data gathering. Results: The prevalence o
... Show MoreBackground: Sclerotherapy is a simple treatment modality for treatment of infantile hemangioma and slow-flow vascular malformations; Polidocanol is a mild sclerosing agent that is traditionally used in treatment of varicose veins. This study aims to evaluate the effectiveness, treatment outcome, and complications of polidocanol foam sclerotherapy for infantile hemangioma and slow-flow vascular malformations. Materials and methods: Between March 2013 and December 2014, seventeen patients with infantile hemangioma and slow-flow vascular malformations treated with polidocanol 1% foam sclerotherapy. Foam was prepared by Tessari’s method. Injection performed under general or local anesthesia, injections were repeated (if necessary) on mon
... Show MoreSome biological aspects of the zebra mussel, Dreissena polymorpha have been studied at Al-Musayab thermal power plant ,sixty km. south west of Baghdad. Data collected during the period extended from November, 2002 to October, 2003 except for the month of April The population consisted of five age groups; O, I, II, III, and IV which have 0, 1, 2, 3 and 4 annuli respectively. The study also proved the validity of annuli readings for age and growth determination. The average annual growth rates for age groups O,I, II, III, and IV were 5.7, 5.5, 5.4, 5.2 and 5.4 respectively. Average calculated length for laboratory reared mussel was 2.5 mm compared to 5.4 mm in natural environment. Correlation coefficients were very high between age an
... Show MoreObjectives of this project were to study the effect of 60% crude alcoholic extract of the seeds of cyperus esculentuson induced endometritis in the mice . The plant of cyperus esculentuswas extracted by preparing Alcoholic extract 60% . One hundred microliters of saline containing Escherichia coli (104cfu) was used to induce endometritis, by a single intracervicallyinjection, and endometritis developed after 2 days from injection. The mice were divided into five groups, The first group were treated with alcoholic extract of cyperus esculentusextract 150mg/kg body weight, the second group was treated with a daily 3mg per kg body weight of gentamicin given intra peritoneal,The third group was treated by 75mg/kg of cyperus esculentusextract an
... Show MoreThe concept of power despite its implications unclear and unknown was one of the most standards in international relations ambiguity and lack of clarity, however was more standards important and influential in the conduct of international relations, and since that time until today since that ambiguity in the meaning of power and use it as a factor of international relations factors and drive the engines were very different and irony from case to case and from researcher to another, but it may be classified force as the international status enjoyed by the state in the international ocean and here is a structure formed of forces posed by the state, such as economic and political nature of the political system and military power and concept
... Show MoreBack ground: Zygote produce from once a sperm fertilizes an egg cell. Then, the zygote (unicellular) will begin chain of cellular cleavages to produce multicellular mass, its embryo, the differentiated to different tissues and organism. The development of the embryo is called embryogenesis. Coenzyme Q10, is an antioxidant produced in the body. It boosts cellular energy and may enhance the immune system. CoQ10 is present and measurable in seminal fluid, the concentration of CoQ10 directly correlates with both sperm count and motility. It is beneficial in the prevention and treatment a wide range of health problems. Objectives: The present study was aimed to investigate the possibility of using coenzyme Q10 to improve in vitro fertilization (
... Show MoreAim: The aim of this study is to determine the correlation between levels of certain seminal biochemical parameters and serum reproductive hormones, on the one hand, and sperm function tests, on the other hand, in asthenospermic patients. Patients and Methods: Sixty asthenospermic patients and twenty fertile men as a control group were included in this study. Semen samples were collected to perform seminal fluid analysis. Total protein, cholesterol, calcium, creatine kinase, and fructose were measured in the seminal plasma. Blood samples were collected for hormonal assay of serum reproductive hormones: testosterone, prolactin, luteinizing hormone, and follicle-stimulating hormone. Results: The results revealed a significant positive correla
... Show MoreThe aim of this study is to investigate the sedimentation environments and diagenetic processes of the Ibrahim Formation (Oligocene-early Miocene) in Zurbatiya, eastern Iraq. The Ibrahim Formation is comprised mostly of clayey micrite and skeletal grains composed of planktonic foraminifera, calcispheres, radiolaria, and benthic foraminifera. Glauconite and pyrite were documented in some restricted zones of this formation; they reflect quiet and reducing conditions. Radiolaria were identified in Late-Oligocene which was not known previously at this age regionally in carbonate formations of the Arabian Plate (AP). Mudstone, wackestone, and planktonic foraminiferal wackepackstone are the main microfacies that are affected by dissolutio
... Show MoreThis study presents certain modifications done to the conditions set by Searle
(1969: 57) concerning the speech act of promising in order to render them to selected
sayings of Prophet Muhammad (P.B.U.H.) and Jesus Christ (P.B.U.H.) and to
political texts. These modifications make the conditions of the speech act of
promising appropriate for sincere promises made by the Messengers of God since
they deliver their Messages of God but they are unable, as Messengers, to fulfill
God’s promises which they make as part of their Messages and by representatives of
States who deliver speeches on behalf of their Governments. These are the only two
situations where the speakers can make promises and do not fulfill these prom