Massive multiple-input multiple-output (MaMi) systems have attracted much research attention during the last few years. This is because MaMi systems are able to achieve a remarkable improvement in data rate and thus meet the immensely ongoing traffic demands required by the future wireless networks. To date, the downlink training sequence (DTS) for the frequency division duplex (FDD) MaMi communications systems have been designed based on the idealistic assumption of white noise environments. However, it is essential and more practical to consider the colored noise environments when designing an efficient DTS for channel estimation. To this end, this paper proposes a new DTS design by exploring the joint use of spatial channel and noise covariance matrices, when the channel is not reciprocal but the coherence block length remains limited. We derive an analytical solution for the mean square error (MSE) based on the proposed training design with colored noise. In addition, this paper exploits the method of random matrix theory to provide an analytical solution for the downlink (DL) achievable sum rate of the regularized zero forcing beamforming (RZFBF) precoder. Numerical results demonstrate that using the proposed DTS design, the MSE of the channel estimate is significantly reduced compared with the conventional training designs with white noise. Furthermore, the results show that the proposed pilot design markedly improves the DL achievable SR over the conventional training designs, especially at relatively low signal-to-noise-ratio (SNR) levels. This enables FDD MaMi systems to operate under more practical scenarios of colored noise and limited coherence time environments.
Objective: The study aimed to assess Leucine-rich alpha-2-glycoprotein-1 biomarker serum level in hospitalized COVID-19 patients. Methods: The case control study from multi-centers in Baghdad included 45 adult patients (19 females and 26 males) with COVID-19, diagnosed with a positive real-time reverse transcription polymerase chain reaction and excluded negative RT-PCR for COVID-19 and comorbidity conditions. Second group, was 43 control (20 females and 23 males). Results: This study found a decrease Leucine-rich alpha-2-glycoprotein-1 biomarker serum level in these patients and a significant difference in D. dimer, neutrophil count, lymphocyte count, and the neutrophil-lymphocyte ratio between the patients and controls at a P valu
... Show MoreBackground: Neonatal period is a very vulnerable period of life due to many problems, In spite of advances in perinatal and neonatal care still, the mortality rate of neonate high especially in developing country The World Health Organization estimates that globally four million neonatal deaths per year, Developing countries account for around 99% of the neonatal mortality in the world, In Iraq. Neonatal mortality rate about 19 per 1000 live births which represent 56% of child death below 5 years age in 2012. The hospital in the study represents the larger pediatric hospital in Iraq. It contains 400 children's beds and 24 neonatal incubators.
Aims of the study: are to determine the institutional
... Show MoreThis work is devoted to the modeling of streamer discharge, propagation in liquid dielectrics (water) gap using the bubble theory. This of the electrical discharge (streamer) propagating within a dielectric liquid subjected to a divergent electric field, using finite element method (in two dimensions). Solution of Laplace's equation governs the voltage and electric field distributions within the configuration, the electrode configuration a point (pin) - plane configuration, the plasma channels were followed, step to step. The results show that, the electrical discharge (streamer) indicates the breakdown voltage required for a 3mm atmospheric pressure dielectric liquid gap as 13 kV. Also, the electric potential and field distributions sho
... Show MoreAbstract:- Cyberspace is a new arena for conflict between international powers, especially since the cost of cyber-conflict is less than its traditional warfare counterparts regardless of the nature of the weapons used, whether traditional or non-traditional. Cyber conflict is necessarily based on strategies to deter, attack, and defend. The aim of the cybercrime conflict is to ensure the defensive sufficiency of the state, ensuring its national security and safeguarding its supreme interests. Despite Japan-China relations characterized by convergence and cooperation in post-Cold War economic spheres, Japan continues to retain the growing Chinese influence in East Asia. These variables prompted Japan to announce a hedging strategy due to un
... Show MoreBackground: Dental anomalies might occur due to abnormal events during teeth development caused by environmental or genetic factors during histo differentiation or morph differentiation stages of embryological development. Aims of the study: To evaluate the distribution of developmental dental anomalies according to age and gender in relation to nutritional status in children attending College of Dentistry /University of Baghdad. Materials and method: After examination 5760 children aged 5-12 years of both genders only 147child with dental anomalies were found, all developmental dental anomalies that were clinically observable were recorded. The developmental dental anomalies which diagnosed in this study were supernumerary, missing teeth,
... Show MoreBackground: Uncontrolled hyperphosphatemia is the main difficulty facing staff treating patients with end-stage renal disease on hemodialysis. Sevelamer and calcium-containing phosphate binders have been associated with cost burden and tissue calcification, respectively. Therefore, the current trial was targeted to investigate the efficacy of a new phosphate binder, ferric citrate, in a sample of Iraqi patients with end-stage renal disease on hemodialysis. Keywords: Ferric citrate, Hemodialysis Phosphate binder
The objective of this work was to determine and compare the physiological changes in some: blood components (packed cell volume and hemoglobin) and plasma biochemical parameters (glucose, total protein, albumin, cholesterol and triglycerides) under 3 day of different types of stress: water deprivation, starvation, overcrowding and handling stress. Twenty five male Wister rats weighted 100-120 gm, were divided randomly into five groups: control, water deprivation, starvation, overcrowding and handling stress. On the third day of stress the animals anesthetized for blood collection; the results of blood component revealed a significant increase in PCV and a significant decrease in Hb of water deprivation group and starva
... Show MoreThe problem of research is that the colleges of education in general and the College of Education in particular continue to follow traditional administrative patterns and that there is a complaint that the educational outputs do not match the aspirations of the society and its future directions. The aim of the research is to identify the reality of quality assurance standards in the college and to create a future vision for these standards to apply them. The researcher has designed a questionnaire based on the responses of the research sample which consisted of a group of university teachers to identify the quality assurance standards. The findings revealed that it is necessary to find a clear approach to apply the standards of quality i
... Show MoreMyelosuppression is one of the serious adverse effects of cancer chemotherapy that lead to life threatening febrile neutropenia and considered a limiting factor for successful therapy. Cyclophosphamide a widely used anticancer drugs, induces severe bone marrow suppression by damaging hematopoietic stem cells. As cancer incidence expands globally, the demand for an effective myeloprotective therapy during cancer treatment is also increasing.Nigella sativa seed oil, a well-known plant extract that widely used for various health conditions. This study aims to evaluate the myeloprotective activity of Nigella sativa seed oil in cyclophosphamide-induced myelosuppression mice model. Myelosuppression induced by single intraperitoneal injection o
... Show MoreBackground: Hypothyroidism is the most abundant thyroid disorder worldwide. For decades, levothyroxine was the main effective pharmacological treatment for hypothyroidism. A variety of factors can influence levothyroxine dose, such as genetic variations. Studying the impact of genetic polymorphisms on the administration of medications was risen remarkably. Different genetic variations were investigated that might affect levothyroxine dose requirements, especially the deiodinase enzymes. Deiodinase type 2 genetic polymorphisms’ impact on levothyroxine dose was studied in different populations.
Objective: To examine the association of the two single nucleotide polymorphism (SNP)s of deiodinase t
... Show More