Items of № 4, 2020

The Electrosvyaz Magazine is one of the leading science & technical magazines in Russia.

ELECTROMAGNETIC SECURITY OF MODERN WIRELESS TECHNOLOGIES: ICNIRP DOCUMENTS

  • Yu.M. Spodobaev, FSUE Branch NIIR — SONIIR, chief researcher, professor, Dr.Sci.(Tech.); spod@soniir.ru.

Keywords: electromagnetic fields, ICNIRP recommendations, network technologies, consolidation of studies.

The ICNIRP recommendations, which provide guidelines for many countries in protecting people from electromagnetic fields, have been substantially updated this year. The new document was developed on the basis of the results of the consolidation of multi-year studies with the consistent implementation of the concept of monitoring and evaluation of electromagnetic energy absorbed by an object. Some provisions of the document, which are of interest to technical specialists from scientific, technical and methodological points of view, are considered. It is shown that electrodynamic validity, established boundaries, time parameters and the degree of impact correspond to the basic physical concepts.

ACHIEVABLE ERROR LEVELS OF THE PASSIVE GONIOMETRIC LOCATION OF RADIATION SOURCES BASED ON THE MAXIMUM LIKELIHOOD METHOD

  • V.N. Yudin, Moscow Aviation Institute (MAI), department of theoretical radio engineering, professor, Dr.Sci.(Tech.); vn_yudin@mail.ru;
  • A.M. Volkov, MAI, department of theoretical radio engineering, postgraduate; afv92@yandex.ru.

Keywords: goniometric passive radar method, positioning accuracy, maximum likelihood method.

Options for improving the accuracy of the goniometric passive location of radiation sources using a single aircraft carrier and a location algorithm based on the maximum likelihood method are considered. Achievable levels of location errors are estimated for various conditions of aerial reconnaissance of radiation sources.

INFLUENCE OF A PRIORI INFORMATION ON THE MULTIPLE MODEL ALGORITHM CONVERGENCE DURING TRACKING A BALLISTIC TARGET

Keywords: target tracking, ballistic trajectory, multiple model filtration, a priori information, reentry target.

The problem of reentry ballistic target tracking with a passive antenna array is considered. Multiple model algorithm based on extended and sigma-point Kalman filters is proposed. A priori information accuracy influence on the convergence of multiple model algorithm is analyzed. Using mathematical modeling, the results were compared with regular extended Kalman filters.

TRENDS AND CONCEPTS OF DEVELOPMENT OF COMMUNICATION NETWORKS USING NON-GEOSTATIONARY SATELLITE CONSTELLATIONS

Keywords: low-orbit communication network, orbital constellation, satellite-relay, inter-satellite communication line, multi-beam antenna.

The trends and concepts of satellite communications networks based on non-geostationary orbital constellations are considered. Analysis of existing and prospective networks is based on a large number of performance indicators, such as parameters of orbital constellations, type of antennas, construction of an information exchange system (protocols for multiple access and separation of communication channels, protocols for routing and transmitting information over communication channels), and cost.

A BAND ENHANCEMENT OF PATCH ANTENNAS BY THE DISTRIBUTED EXCITATIONS

Keywords: patch antennas, microstrip antennas, broadband antennas, digital array antennas.

Models of patch antennas are developed. The possibility of extending the working band of patch antenna with the help of distributed excitation is shown. Directional characteristics and frequency characteristics of patch antennas are determined.

MEASURING ACTIVE FERRITE ANTENNA AFA-1M

  • Yu.A. Nikitin, The Bonch-Bruevich Saint-Petersburg State University of Telecommunications (SPbSUT), associate professor, FSUE NIIR-LONIIR, head of a laboratory, Ph.D.; yuriyan@list.ru;
  • S.A. Belov, FSUE NIIR-LONIIR, head of a section; emc@loniir.ru;
  • S.Yu. Cherniavsky, NITA Company Ltd., electronic engineer; ttl1@rambler.ru.

Keywords: active antenna, magnetic antenna, magnetic field strength, antenna calibration factor.

The article describes the small-sized broadband active ferrite antenna AFA-1M for measuring magnetic fields in the frequency range from 10 Hz to 300 kHz. The antenna can be used as an independent product and as a part of automated measuring systems for measuring electromagnetic fields of interference, as well as to verify the protection of information from unintentional leakage due to spurious electromagnetic radiation.

USING THE FLOYD-WARSHALL ALGORITHM TO FIND THE TRANSMISSION ROUTE OF THE SYNCHRONIZATION SIGNAL WITH A MINIMUM NUMBER OF RECEPTIONS

  • M.V. Lobastova, SPbSUT, department of communication networks and data transmission, senior lecturer, postgraduate; mlobastovabk1@rambler.ru;
  • A.Yu. Matyukhin, SPbSUT, department of communication networks and data transmission, associate professor, Ph.D.; matukhin@list.ru.

Keywords: clock network synchronization, the shortest route, resynchronization signal, oriented graph, Floyd-Warshall algorithm, 5G network.

Effective use of digital transmission systems is impossible without the competent organization of clock synchronization. The article considers one of the problems of organizing clock network synchronization, namely, the transmission of a synchronization signal with a minimum number of re-receptions. To find the most efficient route for transmitting the synchronization signal, it is proposed to use the Floyd-Warshall algorithm.

ADVANTAGES OF AMOOFDM SYSTEM OVER OTHER TECHNOLOGIES: A REVIEW

  • H. Yazbeck, Peoples' Friendship University of Russia (RUDN University), Engineering Academy, postgraduate; 1 042 175 153@pfur.ru;
  • V.V. Belyaev, RUDN University, Engineering Academy, professor, Dr.Sci.(Tech.); vic_belyaev@mail.ru;
  • I.M. Tkachenko, RUDN University, Engineering Academy, associate professor, Ph.D.; tkachenko-im@rudn.ru.

Keywords: wireless communication, digital subscriber line, DSL, passive optical network, PON, adaptively modulated optical orthogonal frequency multiplexing, AMOOFDM, semiconductor optical amplifier, SOA.

Access networks are under constant development looking for customer’s satisfaction by enhancing the Internet service speed and the cost of the service. However, a significant percentage of these networks still using the terrestrial radio wave telecommunications to distribute the service inside or between city blocks, while others use the fiber to the home (FTTH). The article compares the performance of the currently operated access networks to the adaptively modulated optical orthogonal frequency multiplexing (AMOOFDM) based access networks, according to the bit-rate, and the distance reach of these networks. The advantages of the AMOOFDM system, in which a semiconductor optical amplifier (SOA) is used as an intensity modulator, are shown.

THE BASICS OF SELECTING THE OPTIMAL PARAMETERS OF ERROR-CORRECTING CODES FOR TELECOMMUNICATION SYSTEMS

  • M.A. Bykhovskiy, Moscow Technical University of Communications and Informatics (MTUSI), professor, Dr.Sci.(Tech.); bykhmark@gmail.com.

Keywords: error-correcting codes, optimal signal transmission techniques, multidimensional signal ensembles, reliability of message reception.

The basic principles of selection of parameters of error-correcting codes for communication systems are considered. Formulas, that allow determining the probability of decoding errors of different codes depending on their length and the probability demodulation errors of signals, are given. It is shown that Reed-Solomon (RS) codes of a sufficiently large length make it possible to ensure high noise immunity of receiving messages. It is also shown that in a communication system in which messages are transmitted using multidimensional signal ensembles, and error-correcting codes are not used, messages can be transmitted at a given speed with a minimal signal/noise ratio at the input of the demodulator. A comparison of the parameters of communication systems with RS codes and the DVB-S2 satellite communications system with binary low-density parity-check codes (LDPC) is performed. It is shown that high transmission reliability in the system is achieved by using an RS code having a significantly shorter length than the LDPC code.

A TUNABLE COMPLEX BANDPASS FILTER WITH SWITCHABLE CAPACITORS

  • Yu.A. Grebenko, National Research University «Moscow Power Engineering Institute» (MPEI), professor, Dr.Sci.(Tech.); GrebenkoYA@mpei.ru;
  • Aung Ko Min, MPEI, postgraduate; akmin53@gmail.com.

Keywords: complex bandpass filter, switchable capacitor, complex link on inverting integrators, independent tuning of center frequency and bandwidth, method of converting an active RC filter.

The article is devoted to the development of a method for calculating complex filters on switchable capacitors based on analog prototypes. It is proposed the method of converting an active complex RC filter by replacing resistors with switchable capacitors. It is considered the application of identical complex links with inverting integrators, which allow the tuning of parameters of a complex bandpass filter by the synchronous change of parameters of identical complex links. As an example, a schematic diagram of a complex bandpass filter with 2nd order Butterworth low-frequency prototype with switchable capacitors is developed.

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