Journal of Communications Technology and Electronics最新文献

Abstract

The properties of the models of indexation of administrative subjects according to the compound of socioeconomic indicators are investigated. Interest in the study is caused by the fact that there is no single best method for assessing the state of administrative entities, since the state of the subject is a multifaceted characteristic and various methods of indexation reflect different aspects of its condition. It should also be kept in mind that indexation is only an auxiliary tool that facilitates a comprehensive assessment of the state of the subject. Therefore, there is a need for the study of indexation methods properties that allow objective assessment of the subject’s state on the basis of existing heterogeneous data. This study is limited by the consideration of a group of indexation models based on the principle of ranking. The properties of indexing models are studied on the example of evaluating of the children well-being index. For the analysis and illustrations of the properties of the models under consideration, the indicators for 85 regions of the Russian Federation are used.

Abstract

The phase diagram of a non-centrosymmetric ferromagnet in the presence of a biharmonic light field is constructed. The possibility of helical magnetic structures in instability zones is shown and their properties are analyzed. Practical application of the results is discussed.

Abstract—In this paper, we examine the problem of resource virtualization in 5G wireless networks that employ multiple-access technology using MU-MIMO (Multiple User-Multiple Input Multiple Output). Network resource virtualization is a key approach to allocating network resources in 5G networks while MU‑MIMO complicates the problem of allocating wireless channel resources across virtual subnets, as well as between individual clients. To solve this problem, we use here the DeSlice virtualization architecture and develop a radio resource planning method that takes into account the characteristics of both the resource virtualization problem and MU-MIMO and various types of traffic, including virtual reality application traffic and web traffic. Using simulation, we demonstrate that the developed radio resource planning method significantly improves the quality of service for both types of traffic compared to the standard system. The performance evaluation results demonstrate the effectiveness of the developed method for resource allocation in a MU-MIMO system supporting network resource virtualization technology.

Abstract

The electronics features of a portable infrared Fourier transform spectrometer are considered. A description of its most important components and justification for the use of the corresponding element base are given; structural diagrams are outlined, an analysis of the most significant electronic units of the device and their functioning is carried out. The results of experimental studies are presented.

Abstract

The electrodynamic properties of the plasma of a radio-frequency capacitive discharge with a magnetic field along the capacitor plates are considered. The complex impedance of such a system is calculated. Based on the equivalent electrical circuit of a plasma capacitor, the resonant properties of the discharge are analyzed. The role of ions in the stability of an electron flow drifting in crossed electric and magnetic fields has been demonstrated.

Abstract

The monograph is devoted to research and development of methods for analysis of physical systems based on theories of R- and atomic functions, WA-systems of functions, the construction of processing algorithms, and simulation of remote sensing and radio astronomy processes with the objective of improving the physical characteristics of the transmission, recovery, and recognition of multidimensional signals. The new weight functions (windows) and finite impulse response filters based on them, as well as analytical and orthogonal wavelets are described. The generalized sampling theorem based on atomic functions and its special cases are studied. The algorithm of synthesis of multidimensional functions with a reference area of the complex shape geometry is developed. The generalization of the ambiguity function of time and frequency in relation to the analysis of complex sounding signals is proposed and substantiated. The book is intended for researchers, postgraduates, and students working in the field of digital signal processing as applied to current problems of radio physics and radioengineering.

Abstract

The decomposition of an ultrashort pulse into a sequence of pulses with lower amplitudes in a modal filter on a double-sided PCB is experimentally shown. Quasi-static simulation is performed to confirm the experimental results. In the experiments, the attenuation factor is 5.4 with respect to one half of the EMF and the bandwidth is 120 MHz. Under short circuit (SC) and open circuit (OC) boundary conditions at the ends of the passive conductor, attenuation factor and bandwidth are increased to 6.7 and 150 MHz, respectively. The presence of additional pulses under SC–OC conditions is shown, and the integrity of the useful signal is analyzed.

Abstract—

The results of numerical simulation of a multiple-beam X-band klystron have been presented. The analysis of a new principle of constructing the interaction space that allows us to provide a high efficiency value without using second harmonic resonators has been given. The results of an experimental study of the developed 25-beam KIU-283 klystron with a peak power of 3.0 MW at a frequency of 9300 MHz with an electronic efficiency of 58% have been presented.

Abstract

The features arising from the optimization of strip modal filters (MFs) using a genetic algorithm (GA) and evolutionary strategies (ESs) are considered. Sequential optimization of microstrip MFs and MFs with broad-side coupling was performed according to the criterion of minimizing the maximum amplitude of the output voltage. The results of such optimization with different numbers of calculations are presented, including the values of the optimized parameters, the objective function, the time spent on the calculation, stopping criteria (when optimized by ESs) and the voltage waveforms at the output of the studied MFs. A detailed analysis of the results of the two algorithms is presented. The advantages and disadvantages, as well as differences in the operation of each algorithm, are determined using the example of optimization of two MFs.

Abstract

As alternative wireless channels for widespread notification of miners, the use of electromagnetic waves of infralow frequencies, 0.3–3 kHz and very low frequencies, 3–30 kHz of ranges, is considered. The transmission of the signal using a long-length grounded antenna or loop magnetic antenna is investigated. The influence of the basic physical parameters of rocks on the propagation and absorption of a low-frequency electromagnetic field is investigated. The comparative analysis of the efficiency of radiation using a magnetic frame and a long-length grounded antenna in the frequency range of 0.5–30 kHz is given. The analysis of the maximum depth of penetration of the magnetic field of antennas through rocks and coverage areas to a depth of 1000 m. The results of experiments at the mine in the transmission of a useful signal with frequency and amplitude manipulation are given.