Massive multiple-input multiple-output (m-MIMO) is considered as an essential technique to meet the high data rate requirements of future sixth generation (6G) wireless communications networks. The vast majority of m-MIMO research has assumed that the channels are uncorrelated. However, this assumption seems highly idealistic. Therefore, this study investigates the m-MIMO performance when the channels are correlated and the base station employs different antenna array topologies, namely the uniform linear array (ULA) and uniform rectangular array (URA). In addition, this study develops analyses of the mean square error (MSE) and the regularized zero-forcing (RZF) precoder under imperfect channel state information (CSI) and a realistic physical channel model. To this end, the MSE minimization and the spectral efficiency (SE) maximization are investigated. The results show that the SE is significantly degraded using the URA topology even when the RZF precoder is used. This is because the level of interference is significantly increased in the highly correlated channels even though the MSE is considerably minimized. This implies that using a URA topology with relatively high channel correlations would not be beneficial to the SE unless an interference management scheme is exploited.
Background: Adjustment of any premature occlusal contact of any zirconia restoration requires its polishing or glazing in order to restore the smoothness of the restoration. The objective of this in vitro study was to evaluate the effects of different polishing systems and glazing on the surface roughness of full-contour zirconia. Material and methods: Forty disks (diameter: 8 mm, thickness: 6.4 mm) were prepared from pre-sintered full-contoured zirconia block; they were colored and sintered in a high-temperature furnace at 1500ËšC for 8 hours. The specimens were then leveled and finished using grinding and polishing machine and adjusted using diamond disk. The specimens were then randomly divided into four groups (n=10), group I involves
... Show MoreAn experiment was carried out on the fields of the college of Agriculture - Abu Ghraib, of a silty clay loam soil that has moisture of 15-16%, to study the effect of plowing and pulverization systems on some plant indicators of onion. The experiment included plowing systems with three levels (plowing with a moldboard plow, plowing by chisel plow and zero tillage plowing) as a primary factor. The second factor was that pulverization for only one time and repeating the pulverization twice through the use of the rotary tiller. The plant indicators of onion that are studied: plant length, onion diameter, onion weight and onion neck diameter. The experiment has carried out according to SPLIT PLOT design according to RCBD design by three replicat
... Show MoreThe current study aimed to reveal the role of the high school (boys) in the Governorate of Qurayyat (KSA) in promoting intellectual security of students, and whether there were differences in the estimates of the study sample due to the variables; the current position, academic qualification, teaching specialization and years of experience. This study was conducted by applying the analytical descriptive method, and used questionnaire as a tool for data collection. The survey consisted of (44) ite
... Show MoreInterested in many scholars and reseachers the subject of the media and means varied his roleinfluential in the definition of the public of issues and political, cultural, social and because of its spread wide and ability to address the people of all levels effect them in the formation consciousness of those issues and types of this awareness is an awareness of the tax, contribute to media formation consciousness tax through the definition of people what tax and importance of the role of its revenues to supplement the state budget by posting tax laws and regulations of applied and all what respect process account tax, to be in charge of the tax familiar enough about this, which avoid being cheated taxmisleading when rev
... Show MoreUniversities are among spaces where it's important to ensure thermal comfort in indoor spaces, improving the occupants' well-being and productivity. The problem of the research was to study appropriate glazing systems for the spaces of the University of Baghdad because glazing systems are one of the most important elements of the indoor environments, and it has a major impact on the thermal performance of buildings. Glass is one of the most seasoned materials that are most utilized in the design. Since it is a diaphanous material, it allows sunlight to enter the building, increasing the space's temperature, cooling loads, and energy consumption in summer. The research followed the experimental method by studying and
... Show MoreWomen issues occupy an important place in international and development projects and programs. This is one of the goals of 21 Century announced during universal summit conference in 2000. The goals are : teaching children, reducing the average of the dead, in addition to the main goal which is reducing the poor level in 2015.
The increasing number of countries that adopt democratic policies, economic freedom and openness lead to heighten and develop the role of women in different ways. As a result, many feminism journals have appeared. Since journals help people to make decisions about public issues as well as acquiring new knowledge, it stimulates women to make decisions.
Feminism journalism takes a new trend. It has become specia
It is necessary to examine the nature of the Turkish position and what Turkey seeks to achieve at the international, regional and Iraqi levels. Or is this external role an expression of foreign policy and has not yet reached the level of maturity that reaches the stage of strategy? The answer to this question is the essence of research in the Turkish role. The answer to this question requires the realization of the elements and pillars that guarantee Turkey's continuity and survival. Continuity is a cornerstone of the strategy. The continuity of the role and its interaction with the event and the ability to employ multiple alternatives are what qualify the state to describe its politics. The external strategy has evolved into. In order t
... Show MoreAbstract The aim of this study is to identify the role played by the university in reinforcing the culture of voluntary work in college students and sequencing these roles according to their priority. To achieve this aim, the researcher used the descriptive approach. After being informed of the literature background and of the previous studies related to the core aim of this recent study, the researcher has built up a questionnaire of (20) items investigating the role of university in reinforcing the culture of voluntary work in the college students. The standardized features of the questionnaire have been checked for the purpose of the questionnaire validity (virtual and constructive validity) and stability (reconstruction and Cronbach's A
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