Journal of Communications Technology and Electronics
Journal of Communications Technology and Electronics is a peer-reviewed journal that publishes articles on a broad spectrum of theoretical, fundamental, and applied issues of radio engineering, communication, and electron physics. It publishes original articles from leading scientific and research centers. The journal covers all essential branches of electromagnetics, wave propagation theory, signal processing, transmission lines, telecommunications, physics of semiconductors, and physical processes in electron devices, as well as applications in biology, medicine, microelectronics, nanoelectronics, electron and ion emission, etc. The journal publishes original manuscripts submitted in English, as well as works translated from several other journals. The sources of content are indicated at the article level. The peer review policy of the journal is independent of the manuscript source, ensuring a fair and unbiased evaluation process for all submissions. As part of its aim to become an international publication, the journal welcomes submissions in English from all countries.
Peer review and editorial policy
The journal follows the Springer Nature Peer Review Policy, Process and Guidance, Springer Nature Journal Editors' Code of Conduct, and COPE's Ethical Guidelines for Peer-reviewers.
Approximately 1% of the manuscripts are rejected without review based on formal criteria as they do not comply with the submission guidelines. Each manuscript is assigned to one peer reviewer, who can either be an external expert or a member of the Editorial Board. When the reviewer is a member of the Editorial Board, they will write the review themselves. In special cases (for example, when the topic of the article is interdisciplinary), two reviewers are assigned to the article. The journal follows a single-blind reviewing procedure. The period from submission to the first decision is up to 6 weeks. The approximate rejection rate is 15%. The final decision on the acceptance of a manuscript for publication is mostly made by the responsible editor and sometimes by a meeting of the most active members of the Editorial Board.
If Editors, including the Editor-in-Chief, publish in the journal, they do not participate in the decision-making process for manuscripts where they are listed as co-authors.
Special issues published in the journal follow the same procedures as all other issues. If not stated otherwise, special issues are prepared by the members of the editorial board without guest editors.
Edição corrente
Volume 64, Nº 12 (2019)
- Ano: 2019
- Artigos: 28
- URL: https://journals.rcsi.science/1064-2269/issue/view/12560
Electrodynamics and Wave Propagation
Mathematical Problems of Radiation and Propagation in Electromagnetic Waveguides
Resumo
The radiation problem in a regular waveguide with inhomogeneous filling and the scattering problem in a hollow irregular waveguide are considered. The completeness of the system of waveguide root vectors is proven. The radiation conditions are set and the solvability of the excitation problem is established. The dispersion curves of the waveguide with anisotropic filling are analyzed. The singular points of dispersion curves are considered. The excitation problem for a waveguide in a resonance regimen is investigated. The embedding theorems for the vector fields are proven. The solvability of the scattering problem in a waveguide is established.
Study of Coniferous Forests Using Multifrequency Polarimetric Synthetic-Aperture Radar
Resumo
Specific features of radio reflection of coniferous forest in decimeter- and meter-wavelength ranges are considered. The study is stimulated by the upcoming (in five-to-seven years) spaceborne experiments using synthetic-aperture radars (SARs) working in the P-band (430 MHz), which is important for sounding of forests. Experimental results on the reflection characteristics of pine forests obtained with the aid of multifrequency polarimetric SAR are presented. Reflection from forests is simulated for the meter-wavelength range for horizontal (HH) and vertical (VV) polarizations. It is shown that different effects may determine reflection of meter-wavelength waves with HH and VV polarizations. New results on specific features of airborne and spaceborne radar images (RIs) of forests in the L, P, and VHF bands are obtained. Typical features of the RIs of coniferous forests are revealed. Such features are difficult to interpret and need to be further studied using RI analysis and results of simultaneous measurements of soil and forest parameters. Several examples show that RI interpretations may cause doubts concerning the correctness.
On Plasmon Resonances of a Finite Plate Made from a Metamaterial
Resumo
Abstract—The article considers the two-dimensional problem of diffraction of a cylindrical wave by a dielectric plate of finite size, the medium of which has simultaneously negative relative dielectric permittivity and relative magnetic permeability. For an electrically thin plate made from such a dielectric (metamaterial), it is shown that the near-field features are related to surface wave (plasmon) resonances. The effect of loss of the medium and the position of the source of a cylindrical polarized TM-wave on plasmon resonances is studied.
Theory and Methods of Signal Processing
Detection of Groups of Point Objects in Spaces of Different Dimensions Based upon Spatial Compactness Criterion
Resumo
Images of groups of point objects (GPOs) specified in one-, two-, and three-dimensional spaces are considered. We show that the introduction of an associated continuous image (ACI) as an abstract mathematical object relating the elements of the GPO makes possible use of a measure of spatial compactness invariant to the configuration of the GPO. The problem of detecting compact GPOs, including the partially disguised, is reduced to a computationally simple observation-invariant procedure for detecting contrasting areal objects or a structural analysis of a graph of hierarchical grouping of the elements of the GPOs in the scene, which gives similar results. We then find the GPO detection characteristics for various observation conditions.
Computationally Efficient Algorithm for Estimating the Frequency of Signals at the Output of a Channel with White Gaussian Noise and Narrowband Interference
Resumo
Abstract—A computationally efficient algorithm is proposed for estimating the frequency of a quasi-harmonic signal in the presence of narrowband interference based on iterative calculation of the autocorrelation sequence. A feature of the algorithm is the use of an additional filtering procedure that improves its stability. Simulation results have confirmed the proximity of the estimates obtained to the theoretical boundaries.
A High-Frequency Acoustic Pulse Modulator-Splitter with Controllable Polarizations of the Output Channels
Resumo
Abstract—A two-channel high-frequency acousto-optic (AO) modulator-splitter has been developed, which splits optical radiation into two equal optical channels and modulates the intensities of the output channels at double the sound frequency. The modulator makes it possible to simply change the polarization of the output beams. A model of a modulator made of a TeO2 single crystal was used to modulate and split radiation with a wavelength of 0.63 × 10–4 cm. Intensity modulation of the output channels at a frequency of ~200 MHz was achieved.
Spectral Phase Estimation Based on Deep Neural Networks for Single Channel Speech Enhancement
Resumo
Majority of speech processing algorithms operate only with the spectral magnitude, leaving spectral phase unstructured and unexplored. With recent advancement in deep neural networks (DNNs), the phase processing became more important as an innovative and emergent prospective of the DNN based speech enhancement. In this paper, a speech enhancement method based on DNN combined with spectral phase estimation is proposed to improve the quality and intelligibility of the noisy speech. During training, DNNs are trained to learn a mapping from the noisy speech utterances and predict the coefficient to construct an ideal ratio mask for the spectral magnitude. The temporal smoothing unwrapped spectral phase estimation is incorporated as a target and transformed into a structured spectral phase during signal reconstruction. In enhancement stage, the enhanced speech magnitude is reconstructed with estimated structured spectral phase. Experimental results demonstrate success of the proposed method for speech enhancement in terms of the speech quality and intelligibility.
Two Dimensional Direction of Arrival Estimation Algorithm for Coherent Signals Using Three Parallel Uniform Linear Arrays
Resumo
The problem of two dimensional direction of arrival estimation of coherent signals using three parallel uniform linear arrays is investigated. In the proposed method a pre-processing technique, forward and backward spatial smoothing is employed to resolve the coherency. Then the propagator method is exploited for estimating the two dimensional angles with automatic pairing for three parallel uniform linear arrays. Numerical simulations are done to show the efficacy of the proposed method. It validates the estimation accuracy, resolution and robustness of the proposed method.
Position-Aided Fast Beam Training in mm-Wave Multiuser MIMO Systems
Resumo
A position-aided fast beam training in mm-Wave multiuser MIMO systems (PAFBT) method is proposed, in the case of inexact position information. Position information can be used to compute the pointing direction and essentially eliminate the beam alignment overhead. But the incorrect position information will introduce the beam misalignment. To solve the estimated received nodes location uncertainty problem, a beam training scheme is conducted by transmitting the beams to cover critical areas of the received nodes to find out the best transmitter and receiver beams for establishing the links in mm-Wave multiuser MIMO systems. Mathematical and simulation analysis confirm the superiority of the proposed method over the conventional ones in performance.
Radio Phenomena in Solids and Plasma
The Influence of Strains on the Ferromagnetic Resonance Spectrum of Submicron Yttrium Iron Garnet Films Obtained by Ion Beam Sputtering
Resumo
The influence of strains on the ferromagnetic resonance (FMR) spectrum of submicron yttrium iron garnet (YIG) films produced by the ion beam sputtering on gadolinium-gallium garnet (GGG) and silicon (Si) substrates is explored. It is shown that the strain influence is displayed as a frequency shift of the absorption maximum in the FMR spectrum. The results indicate that the studied YIG/GGG and YIG/Si films have an efficient magnetoelastic coupling of the spin and elastic subsystems, which suggests that ion beam sputtering of YIG films on GGG and Si substructures can be a promising technique for production of straintronic devices.
Spin Wave Interference in a Metal Ferromagnetic Plate
Resumo
Abstract—The article studies the polarization of eigenwaves, the total microwave field, and magnetization in a ferromagnetic metal plate. Changes in the polarization and spatial distribution of the total field and magnetization are studied under ferromagnetic resonance and antiresonance conditions. It has been established that in the distribution of the amplitudes of the total microwave field and magnetization, there is both a contribution that decreases monotonically with depth and oscillations caused by spin wave interference. It is demonstrated that the wave interference is especially significant for weakly pinned spins at the film boundaries. It is established that oscillations of the angle of rotation of the polarization ellipse and ellipticity are large when the ferromagnetic antiresonance condition is satisfied.
Applications of Radiotechnology and Electronics in Biology and Medicine
Algorithm for Analysis of Magnetocardiac Signals: The Principal Component Method
Resumo
Nanoelectronics
Spin Polarization of Nonequilibrium Conduction Electrons in Magnetic Junctions
Resumo
An original equation for nonequilibrium spin polarization in magnetic junctions based on dynamic equations for magnetic moment was obtained. Spatial nonuniformity of the distribution of carriers is taken into account in the equations, and the magnetic moment is averaged over the ensemble of nonequilibrium spin-injected electrons. The solution to the dynamic equations for the magnetic moment is used to estimate the probability of spin-flip electron transitions upon spin injection, and the solution to the equation for the nonequilibrium spin polarization in magnetic junctions is used to calculate frequencies of photon emission or absorption at energies corresponding to the energy of effective exchange splitting of spin subbands.
Microstructural Modifications of Diamond-Graphite Nanocomposites for High-Current Field Electron Sources
Resumo
The requirements for cathode materials for high-current field electron sources and problems of their creation have been formulated and justified. Using a nonequilibrium microwave plasma of the low-pressure ethanol vapors, the limits of regimes for forming the nanocomposite film coatings containing the diamond and graphite phases in different volume ratios have been established. The deposition temperature-dependent effect of self-organization of diamond nanocrystallites in the graphite and polymer-like carbon films on quartz and polykor substrates has been found. It is shown that, choosing a regime of the nonequilibrium condensation of diamond-graphite nanocomposites, one can reduce the field electron emission threshold from 15–17 to 4–6 V/μm and enhance the field-emission current density in a microsecond pulse over 100 A/cm2.
Electronic and Ion Optics
Solutions to Equations of a Three-Dimensional Electron Beam in Elementary Functions
Resumo
Abstract—The exact three-dimensional solutions describing nonstationary nonrelativistic electron flows in a uniform magnetic field are given, with preference given to the study of oscillatory regimes.
Novel Radio Systems and Elements
Novel Dual-Mode Microstrip Triangular Patch Resonator Bandpass Filter
Resumo
Some new characteristics of microstrip equilateral triangular patch resonator with fractal defection are analyzed, and novel fractal bandpass filters using equilateral triangular resonator are presented to implement high performances of multi-transmission zeros, wide passband and stopband, and low passband insertion loss as well as miniaturization. Due to the space-filling property of fractal geometry, this structure can adjust the location of the transmission zero, it also effectively control the filter’s size. The proposed filters have compact and simple structures, small sizes, high selectivity and so on, and all these features are the requirement of wireless communication circuits. By adjusting filters parameter, we get the optimized S‑parameters. The resonant frequency shifts to lower frequency locations by increasing hemline length c. Measured results of the filter using three fractal-shaped structures are in good agreement with the simulated ones.
Mathematical Models and Computational Methods
Using Reinforcement Learning in the Algorithmic Trading Problem
Resumo
Abstract—The development of reinforced learning methods has extended application to many areas including algorithmic trading. In this paper trading on the stock exchange is interpreted into a game with a Markov property consisting of states, actions, and rewards. A system for trading the fixed volume of a financial instrument is proposed and experimentally tested; this is based on the asynchronous advantage actor-critic method with the use of several neural network architectures. The application of recurrent layers in this approach is investigated. The experiments were performed on real anonymized data. The best architecture demonstrated a trading strategy for the RTS Index futures (MOEX:RTSI) with a profitability of 66% per annum accounting for commission. The project source code is available via the following link: http://github.com/evgps/a3c_trading.
Artifact Suppression with Geodesic Kernel Filter for Defocused Images Restored by Wiener Filtering
Resumo
Abstract—The Wiener-filter restoration of images degraded by defocus blur usually causes specific low frequency artifacts. In this work, we propose to suppress such low frequency artifacts with a filter based on the geodesic distance affinity. A multispectral signal model is considered and the main idea of the proposed algorithm is based on assumption that low frequency outliers and additive noise in different image channels are uncorrelated. Thus, the affinity space formed by opposite channels can be used to efficiently suppress the Wiener filter restoration artifacts. The performance of the proposed filter is analyzed and compared in terms of the PSNR accuracy.
On Construction of Early Warning Systems for Predictive Maintenance in Aerospace Industry
Resumo
The problem of constructing predictive models for early warning systems for diagnostic maintenance in the aerospace industry is considered. A new approach to predicting rare failures based on a new methodology that takes into account the properties of technical systems and specific requirements imposed by applications is proposed.
Algorithmic Foundations of Predictive Analytics in Industrial Engineering Design
Resumo
We consider the problem of constructing predictive models (surrogate models) to tackle challenges of industrial engineering design. The author analyzed the needs of industrial applications, formulated a number of new mathematical and algorithmic problems and developed appropriate methods of data modeling.
Theory and Methods of Information Processing
Identification in Digital Economy Computer Systems
Resumo
Abstract—A new method of interactive identification is proposed—trusted identification of a person using untrusted devices (e.g., smartphones, tablets, etc.). It is shown that static, unchangeable, or almost invariable biometric features can be used in criminology, but it is impractical for digital economy computer systems. It is inefficient to use fingerprints, iris and retina, vascular pattern, etc., as characteristics. On the contrary, it is necessary to use inherent human dynamic characteristics , for example, those manifested in reflexes. As such, eye movements can be used when reading and/or tracking a stimulus, as well as saccades, pulse wave, and others. For decision-making it is proposed to use artificial neural networks.
A Fast Algorithm of Regularization of the Total Variation for the Class of Radially Symmetrical Functions
Resumo
The total variation regularization for 2D radially symmetrical piecewise constant functions is considered in this paper. The system of equations that solves the direct problem of the total variation regularization with the use of subgradients is obtained. On the basis of the obtained system of equations, the algorithm of calculation of the extremal function is formulated and the geometrical interpretation of the extremal function is given with the use of the modified approach to constructing the taut string. The proposed algorithm of the total variation regularization is used in the 2D case for realizing the adaptive algorithm of the total variation regularization with the variable regularization parameter. The algorithmic complexity of the proposed algorithm of the 1D total variation regularization is equal to the complexity of the known Condat algorithm. The efficiency of the developed algorithm of the total variation regularization is illustrated with the help of computer modeling.
Algorithm for Estimating Type and Probability of Impulse Noise in Color Images
Resumo
Abstract—Color digital images are often contaminated by impulse noise during transmitting and recording of information. Efficient methods for elimination of impulse noise are needed to improve image quality. An algorithm for estimating of the type and probability of impulse noise in color images using morphological operations is proposed. Results of computer experiments are presented to demonstrate the performance of the proposed algorithm for estimating of the type and probability of impulse noise for several interference models.
Data Transmission in Computer Networks
On the Capacity of a 5G Network for URLLC
Resumo
Abstract—The ability to support ultra-reliable low-latency communications (URLLC) is one of the main features of fifth-generation (5G) networks. Strict requirements to the quality of service (QoS), which are typical for URLLC traffic, significantly reduce the wireless network capacity compared to the capacity for mobile broadband traffic. Using simulations, we study the dependence of the URLLC traffic network capacity on the main network parameters such as the used channel bandwidth, cell radius, and the packet delivery time as well as the packet loss ratio that are admissible for URLLC traffic.
Emergency Alert Delivery in a Heterogeneous Wi-Fi HaLow Network
Resumo
Abstract—The concept of the Internet of Things (IoT) has been actively developed in recent years. Wireless networks are the easiest and most convenient way to provide connectivity for IoT devices. A heterogeneous network in which some stations are user devices that transmit saturated traffic while others are sensors that monitor emergency situations and transmit unsaturated traffic is one of the new wireless network scenarios that appeared due to the development of IoT. The article presents a mathematical model for determining the distribution of the emergency alert delivery time in the presence of contention with user devices.
Informational Interaction
Artificial Intellect
Empirical Study of Extreme Overfitting Points of Neural Networks
Resumo
In this paper we propose a method of obtaining points of extreme overfitting—parameters of modern neural networks, at which they demonstrate close to 100% training accuracy, simultaneously with almost zero accuracy on the test sample. Despite the widespread opinion that the overwhelming majority of critical points of the loss function of a neural network have equally good generalizing ability, such points have a huge generalization error. The paper studies the properties of such points and their location on the surface of the loss function of modern neural networks.