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.
The research aims to statement the main obstacles that prevent the application of total quality management (TQM) in a number of Iraqi service organizations, and by one organization in each of the sectors (health, finance, education, higher education, tourism), which are, (Al-Yarmouk Teaching Hospital, Rafidain Bank/ Branch of Hay Al-Arabi Al-Jadid, Al-Karkh/1 Directorate of Education, College of administration and Economics/ Baghdad University, International Palestine Hotel). The research also, tries to classify the priority of the obstacles depending on the type of service organization surveyed. And diagnoses the extent to which or the difference of the research sample members views on the order of obstacles of TQM, and also proposes a
... Show MoreAims: This study was done to investigate the effect of low energy laser therapy on bone healing at the extraction site. Materials and methods:(24) male albino rats were exposed to the extraction procedure of the maxillary first molar on the first day of a seven day experiment and these animals were divided into two main groups; the control group and the laser group. The laser experiment involved using (Ga-As infrared diode laser) from optodent by directing the probe over the extraction site. The control group consisted of 4 rats, and the laser group was subdivided into 5 subgroups of 4 rats each. The laser dose was as follows: B1: a single dose of 5 minutes immediately after extraction.,
... Show MoreInterferon’s plays a role in innate immune responses through upregulation of costimulatory molecules and induction of proinflammatory cytokines. Interferon alpha (IFN α) type of Interferons. The present study characterized IFNα cDNA . The interferon’s play a great role in protection from infections, caused by microorganisms, and have powerful antiproliferative and immunomodulation activity. In this study DNA was isolated from bovine blood leukocyte, which was used in the quality of matrix for amplification of α-interferon gene with the use of PCR, and isolation of gene α-interferon and transformation in vector pUC18 and expression vector pET24b (+). All plasmids contained an additional DNA fragment size corresponding to the gene
... Show MoreThe tax revenues achieved through projects of transition to private sector are regarded as an important source for using in achieving political, economic and social objectives. Since Iraq is heading towards free market economy, new strategies should be adopted to reform the taxation system from by a qualified taxation management office and to activate the taxation policy and to reconsider legislation in relation to the aware of the legible to the importance of disclosure of their taxable real income in order to arrive at contribution of privatization in the taxation revenues for the important role effect on economic activities. In the light of the above, the research is based upon a hypothesis which stipulates that privatization contribu
... Show MoreBackground: Temporomandibular joint disorder (TMD) is a general term that describe a wide variety of conditions that include myogenic pain, internalderangement, arthritic problem, ankylosis of the joint and growth disorders. The aims of study was to evaluate the value of 3 Tesla magnetic resonance imaging in assessment of articular disc position and configuration in patients with temporomandibular joint disorders and to evaluate the correlations of these MRI findings with the clinical signs and symptoms. Materials and methods: A total forty six (30 study and 16 control) participants aged between18 and 49 years, were examined according to Helkimo anamnestic index (questionnaire for anamnesis) and clinical dysfunction index scoring criteria
... Show MoreEleven hymenopterous species: two braconids, seven eulophids and two pteromalids
parasitized the larvae of Phytomyza horticola Goureau. The activity of the parasites began at
the end of April and evidently increased during May. The female of the parasites fed and
parasitized mostly on the second and third larval instars of P. horticola . Diglyphus iseae
Walker and Cirrospilus vittatus Walker were dominant larval parasites. Chrysocharis
pentheus Walker and Pediobius acantha Walker were main pupal parasites.
This study sheds light on various drugs of plant origin which have shown action on thyroid and its functioning as well as on the various factors associated with thyroid dysfunction. Therefore, the aim of this study is to determine the activity of the aqueous extracts of Fucus vesiculosus, Coleus forskohlii, Curcuma longa L., Rosmarinus officinalis L., Camellia sinensis L. and Melissa officinalis L. in regulation of thyroid hormones in serum taken from rats. Fifty-seven female albino rats were divided into 19 groups, each group with 3 rats, and treated orally with an aqueous plant extract in three different doses, except the control group which was treated with normal saline only. Also, a histological s
... Show MoreIn this project we analyze data of a large sample of gas rich dwarfs galaxies including; Low Surface Brightness Galaxies (LSBGs), Blue Compact Galaxies (BCGs), and dwarfs Irregulars (dIr). We then study the difference between properties of these galaxies in the range of radio frequencies (B-band). The data are available in HIPASS catalogue and McGaugh’s Data Page. We depended also NASA/IPACExtragalactic Databes web site http://ned.ipac.caltech.edu in the data reduction. We measured the gas evolution (HI mass), gas mass-to-luminosity ratio, and abundance of the elements such as the oxygen abundance for these galaxies. Our results show a
... Show MoreThis work investigates the effect of earthquakes on the stability of a collective pile subjected to seismic loads in the soil layer. Plaxis 3D 2020 finite element software modeled pile behavior in dry soils with sloping layers. The results showed a remarkable fluctuation between the earthquakes, where the three earthquakes (Halabja, El Centro, and Kobe) and the acceleration peak in the Kobe earthquake had a time of about 11 seconds. Different settlement results were shown, as different values were recorded for the three types of earthquakes. Settlement ratios were increased by increasing the seismic intensity; hence the maximum settlement was observed with the model under the effect of the Kobe earthquake (0.58 g), where
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