Научный журнал «ИНФОРМАЦИОННЫЕ ТЕХНОЛОГИИ И ТЕЛЕКОММУНИКАЦИИ»
Сообщение
2022, Vol. 10, Iss. 4 |
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A STUDY OF THE EFFECT OF ADJACENT AND CO-CHANNEL INTERFERENCE ON THE PERFORMANCE OF A WI-FI NETWORK WITH A CHANNEL WIDTH OF 40 MHZ IN THE 2.4 GHZ BAND
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J. Gerasimova, A. Svetova, R. Dunaytsev
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Abstract: For a long time, Wi-Fi networks have used 22 MHz wide (IEEE 802.11b) and 20 MHz wide (IEEE 802.11a/g) channels only. With the advent of the IEEE 802.11n, it became feasible to combine two adjacent 20 MHz channels to make a 40 MHz channel. By doubling channel width, it is possible to double data rates. However, neighboring Wi-Fi networks using 40 and 20 MHz wide channels can negatively affect each other due to adjacent and co-channel interference. Research subject. In this paper, we present the results of an experimental study of parallel operation of two Wi-Fi networks using 40 MHz and 20 MHz channels in the 2.4 GHz band. Method. To achieve this goal, the following methods of empirical research were used: measurement and experiment. Core results. Using a test bed, parallel operation of neighboring Wi-Fi networks using 40 MHz and 20 MHz channels in the 2.4 GHz band was simulated. Based on the captured traffic, the effective data rate and the retry rate for both Wi-Fi networks were calculated. Practical relevance. The obtained results can be used for manual or automatic configuration of Wi-Fi routers.
Keywords: Wi-Fi, channel width, channel bonding, adjacent channel interference, co-channel interference.
DOI 10.31854/2307-1303-2022-10-4-1-12
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SIMULATION TOOLS FOR IMMERSIVE TECHNOLOGY SERVICES FOR PEOPLE WITH DISABILITIES
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К. Kuznetsov, M. Leonova, A. S. Muthanna
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Abstract: The transfer of immersive technologies will soon be able to transform human life, allowing the implementation of H2M interactions to the fullest and with a new quality. People will be able to protect themselves from hazardous industries, learn faster, provide medical services to highly qualified specialists in the shortest possible time, and much more. The technology provides a paradigm shift towards wireless technology for real-time remote control. At the same time, the introduction of the Tactile Internet concept requires a revision of the principles for building existing and future communication networks. The article describes an experiment in the implementation of immersive technologies in fifth generation communication networks. In the article, a microservice application was created that simulates the movement of a human hand in space, which allows displaying sign language. Ways to reduce delays are also analyzed.
Keywords: immersive technologies, Internet of Things (IoT), fifth generation networks, telepresence services, H2M, latency, robot avatar, 3D gesture imaging.
DOI 10.31854/2307-1303-2022-10-4-13-26
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DEPLOYMENT OF ULTRA DENSE NETWORK DEVICES IN SPACE. PART 2. SEARCH USING GEOMETRIC FACTOR
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G. Fokin, A. Kucheryavy
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Abstract: This work is a continuation of the study devoted to mathematical and simulation modeling of methods for searching for locations of gNB base station devices in space according to the criterion of the geometric factor of reducing the positioning accuracy of the user device UE. The task in this formulation is relevant and in demand for ultra-dense networks of the millimeter (30–300 GHz) and submillimeter or terahertz band (0.3–3 THz) of the fifth and subsequent generations, respectively. As a criterion for the spatial placement of the infrastructure of fixed network devices acting as a base station, access point and / or repeater / router, the geometric factor of reducing the positioning accuracy of the DOP (Dilution of Precision) of the user device is used. Based on the algorithmic, methodological and software, formalized in the previous work for searching for gNB placements in space according to the criterion of geometric factors for reducing positioning accuracy in the horizontal plane HDOP (Horizontal DOP), the vertical plane VDOP (Vertical DOP) and by location in the PDOP (Position DOP) space, this study removes the restriction on the fixed placement of UEs in space, and also provides for an increase in the number of gNBs more than five, for which placements are searched. Subject of study. The article is devoted to mathematical and simulation modeling of methods for searching for locations of base station devices in space according to the criterion of a geometric factor for reducing the positioning accuracy of a user device. Method. Iterative enumeration of all possible locations of stationary base stations and mobile user devices with a given step in space to minimize the geometric factor of reducing positioning accuracy in the selected service area. Main results. The result of this work is the formalization of algorithmic, methodological and software to obtain the final configuration of locations for a given number of stationary base stations in the selected service area. Practical significance. The results obtained make it possible to search for and justify the locations of base stations and/or routers in scenarios of ultra-dense placement of user devices in a space saturated with biomass.
Keywords: super-dense network, placement of devices in space, geometric factor of positioning accuracy reduction, HDOP, VDOP, PDOP.
DOI 10.31854/2307-1303-2022-10-4-27-37
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PHASED ARRAY SYSTEM TOOLBOX PACK OVERVIEW FOR NEW COURSE «5G SMART ANTENNAS TECHNOLOGIES»
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G. Fokin
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Abstract: In the field of smart antenna technologies, approaches based on simulation modeling in special Matlab software, including the Phased Array System Toolbox extension package, deserve special attention. This package provides the implementation of algorithms and methods for modeling antenna arrays (AA) and beamforming (BF) systems in various applications, including radio communication, radar and radio navigation systems. Using the capabilities of this extension package, you can analyze the performance of active and passive AAs of various geometric configurations, including complex AAs formed from composite arrays of elements. The simulation models built with this expansion package allow the formation and processing of signals using models and methods of beamforming, when working on transmission and reception. For LTE and 5G NR mobile networks, satellite systems and WLANs, the PAST extension package allows modeling multipath AAs, including those operating in the adaptive BF mode. The extension package includes models of digital and hybrid BF algorithms that operate as part of massive MIMO spatial signal processing systems in the mmWave. Simulation capabilities in the extension package include, but are not limited to, reproducing fading conditions in a multipath radio channel and evaluating their impact on communication systems with an AP; algorithms and methods for determining signal direction of arrival (DOA). In this paper, we review the coordinate systems used in the PAST extension package. Subject of study. The article is devoted to an overview of the PAST extension package for use in the new 5G Smart Antenna Technologies training course. Method. The study of the possibilities of the PAST extension package is carried out by the simulation. Main results. The result of this work is an overview of the coordinate systems in basic software tools of the PAST extension package for use in the new course "5G Smart Antenna Technologies". Practical significance. This review introduces the capabilities of the PAST extension package and is the foundation of methodological support in the implementation of algorithms and methods for modeling antenna arrays and beamforming systems within the framework of the new training course "5G Smart Antenna Technologies".
Keywords: 5G, Phased Array System Toolbox, antenna arrays, beamforming, coordinate system, smart antennas.
DOI 10.31854/2307-1303-2022-10-4-38-58
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SIMULATION OF THE RECEPTION OF OVERLAPPING SIGNALS USING A WHITEWASHING FILTER AND THE VITERBI ALGORITHM
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V. Vershinin
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Abstract: Frequency efficiency, noise immunity and implementation complexity are the most important parameters of binary message transmission. One of the ways to increase frequency efficiency is the conscious or controlled introduction of intersymbol interference into the transmitted signal with an acceptable reduction in noise immunity. The purpose of the work is to model one of the ways to implement this direction. The formation of the transmitted signal, receiving and processing of samples during reception using a whitewashing filter and the Viterbi algorithm are considered. The noise immunity of the transmission under the influence of interference in the form of white noise is evaluated. The considered method of transmitting binary messages provides good frequency efficiency without using a spectrum shaper with sufficiently high noise immunity.
Keywords: Modeling, overlapping signals, intersymbol interference, frequency efficiency, complex envelope, whitewashing filter, Viterbi algorithm, noise immunity.
DOI 10.31854/2307-1303-2022-10-4-59-68
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APPLYING DECOMPOSITION TO RESEARCH GENERATIVE MUSIC CREATION PROCESSES
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V. Malakhov, G. Rogozinsky
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Abstract: The question of description and selection of groups of generative systems through the study of methods and operations of generating musical compositions is considered. A description of known systems for generating musical compositions is proposed. An analysis of the process of creating generative musical compositions is proposed.
Keywords: generation of musical compositions, neural networks, decomposition, EDF0, EDF3, DFD.
DOI 10.31854/2307-1303-2022-10-4-69-78
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