Items of № 10-2025

Analysis of the status and development trends of hybrid non-terrestrial networks in geostationary orbits

O.A. Ivanov, The M.I. Krivosheev National Research Centre for Telecommunication (NRCT), general director, Ph.D.(Mil.); ivanovoa@nic-t.ru

E.E. Devyatkin, NRCT, director of the Center for research of advanced wireless communication technologies, Ph.D.(Econ.); devyatkinee@nic-t.ru

M.V. Ivankovich, NRCT, deputy director of the Center for research of advanced wireless communication technologies, Ph.D.; ivankovichmv@nic-t.ru

V.O. Tikhvinsky, NRCT, chief researcher, Dr.Sci.(Econ.), Ph.D.; tihvinskiivo@nic-t.ru

A.S. Pastukh, NRCT, head of laboratory; pastuhas@nic-t.ru

D.I. Kalugina, NRCT, specialist; kaluginadi@nic-t.ru

UDC 621.396
DOI: 10.34832/ELSV.2025.72.10.001

Abstract. The article analyzes modern integrated hybrid non-terrestrial networks (NTN) for achieving global mobile communication coverage. Particular attention is paid to implemented direct-access satellite communication projects based on satellites in geostationary orbit (GEO). Systems such as Tiantong and Skylo enable NTN systems to run on standard smartphones equipped with specialized chipsets without requiring any additional hardware. Two key approaches to building the architecture of NTN systems are considered: based on satellite constellations in low non-geostationary orbit (NGSO) and systems in GEO. The advantages and limitations of each approach are examined, as well as the potential of using services from terrestrial-satellite systems with GEO communication satellites as an alternative to NGSO-based services. The prospects for implementing similar technologies in Russia using domestic satellite constellations for communication provision are discussed.

Keywords: hybrid satellite networks, GEO, NGSO, NTN, satellite communications, Tiantong, Skylo, direct-to-device, n254, n255, n256.

For citation: Ivanov, O.A. Analysis of the status and development trends of hybrid non-terrestrial networks in geostationary orbits / O.A. Ivanov, E.E. Devyatkin, M.V. Ivankovich, V.O. Tikhvinsky, A.S. Pastukh, D.I. Kalugina // Electrosvyaz. – 2025. – No. 10. – P. 2-12. (in russian)

Construction of promising civil communication satellites in geostationary orbit for the Russian orbital constellation

O.V. Mentus, The M.I. Krivosheev National Research Centre for Telecommunication (NRCT), Scientific and technical center of satellite telecommunication systems, director; mentusov@nic-t.ru

L.O. Myrova, NRCT, Scientific and technical center of satellite telecommunication systems, chief researcher, professor, Dr.Sci.(Tech.); myrovalo@nic-t.ru

UDC 621.391.81
DOI: 10.34832/ELSV.2025.72.10.002

Abstract. This article provides a comprehensive analysis of global trends in the development of communications satellites in geostationary orbit (GEO). Key technological solutions in the field of payload development are considered, including multibeam antenna systems, digital transparent signal processing, and reconfigurable («flexible») platforms. A comparative study of the competition between GEO systems and multi-satellite constellations in low-Earth orbit (LEO) was conducted. Based on an analysis of international experience and the specifics of the Russian market, a design for advanced civil communications satellites in GEO for the Russian orbital constellation is proposed.

Keywords: satellite communications, geostationary orbit, payload, digital routing, multibeam antenna, multiport amplifier, software-defined payload.

For citation: Mentus, O.V. Construction of promising civil communication satellites in geostationary orbit for the Russian orbital constellation / O.V. Mentus, L.O. Myrova // Electrosvyaz. – 2025. – No. 10. – P. 13-27. (in russian)

Code-multiplexed multiple access based on recurrent sequences over a double-extension field

O.S. Kognovitsky, The Bonch-Bruevich Saint-Petersburg State University of Telecommunications (SPbSUT), department of communication networks and data transmission, professor, Dr.Sci.(Tech.); kogn@sut.ru

A.V. Rabin, SPbSUT, vice-rector for research, associate professor, Dr.Sci.(Tech.); rabin.av@sut.ru

D.S. Kukunin, SPbSUT, department of communication networks and data transmission, associate professor, Ph.D.; kukunin.ds@sut.ru

UDC 512.624.5
DOI: 10.34832/ELSV.2025.72.10.003

Abstract. This paper explores a new method of code-multiplexed multiple access with subscriber channel division based on the use of recurrent sequences over a Galois field with double expansion and dual basis processing. The principles of code-multiplexed channel division on the transmit side and channel division on the receive side are examined using five subscribers as an example. The feasibility of increasing the number of subscribers simultaneously implementing multiple access to a common channel is demonstrated. In addition to Galois field theory, the mathematical basis for the practical implementation of this method is the theory of linear operators implementing the principle of superposition.

Keywords: code compaction, Galois field, double-extension field, dual basis, scalar product of vectors.

For citation: Kognovitsky, O.S. Code-multiplexed multiple access based on recurrent sequences over a double-extension field / O.S. Kognovitsky, A.V. Rabin, D.S. Kukunin // Electrosvyaz. – 2025. – No. 10. – P. 28-43. (in russian)

Evaluation of the correcting ability of LDPC codes and the probability of bit error when using them. Part II

N.V. Lemeshko, JSC Corporation Kometa, deputy head of department, Dr.Sci.(Tech.); nlem83@mail.ru

A.N. Plotnikov, JSC Corporation Kometa, chief designer of the MKP; 89031276391@yandex.ru

I.V. Zmeev, JSC Corporation Kometa, chief designer of the RIUS; zmeev-ivan@yandex.ru

S.M. Gritsenko, JSC Corporation Kometa, head of sector; gricenko1812@yandex.ru

UDC 535.131
DOI: 10.34832/ELSV.2025.72.10.004

Abstract. The article discusses ways to simplify the calculation of the correcting ability of LDPC codes and the probability of bit error when using them for the case of using a generator matrix of canonical form. The second part of the article considers the problem of calculating the bit error probability depending on the ratio of the bit energy to the spectral density of Gaussian noise. Calculation relationships are presented that allow almost completely solving the problems of machine infinity and too small numbers when calculating the bit error probability at the output of the LDPC decoder. For a block of 8000 bits, the results of such calculations are given for the MSK, QPSK, 8PSK, 16PSK, 16QAM, and 32QAM modulations. Conclusions are formulated about the optimality of the bit block sizes when using LDPC coding.

Keywords: LDPC, generator matrix, syndrome matrix, Haming distance, error correction, bit error, symbol error, digital modulation.

For citation: Lemeshko, N.V. Evaluation of the correcting ability of LDPC codes and the probability of bit error when using them. Part II / N.V. Lemeshko, A.N. Plotnikov, I.V. Zmeev, S.M. Gritsenko // Electrosvyaz. – 2025. – No. 9. – P. 44-49. (in russian)

Dynamic model of cash flows – a tool for forecasting the performance indicators, payback and risk of investment projects

V.I. Kotov, The Bonch-Bruevich Saint-Petersburg State University of Telecommunications (SPbSUT), associate professor, Ph.D.; kotov.vi@sut.ru

O.V. Kalimullina, SPbSUT, associate professor, Ph.D.; kalimullina.ov@sut.ru

M.A. Egorova, SPbSUT, associate professor, Ph.D.; egorova2.ma@sut.ru

UDC 330.322.5
DOI: 10.34832/ELSV.2025.72.10.005

Abstract. The paper presents a universal dynamic model of cash flows for developing a financial forecast for investment projects, including projects using digital and information technologies. The model allows for automated calculations of project performance and payback indicators, taking into account inflation and the tax environment within the selected planning horizon. The model allows for quantitative risk analysis of the project based on sensitivity functions and fuzzy set theory.

Keywords: digitalization, investment project, cash flows, net present value, payback period, investment efficiency, risk analysis, sensitivity functions, fuzzy sets, discount rate.

For citation: Kotov, V.I. Dynamic model of cash flows – a tool for forecasting the performance indicators, payback and risk of investment projects / V.I. Kotov, O.V. Kalimullina, M.A. Egorova // Electrosvyaz. – 2025. – No. 9. – P. 50-63. (in russian)

Architectural evolution of 6G networks: distributed intelligence and convergence of space, air, ground and underwater communication systems

Z.A.H. Al-Kerea, The Bonch-Bruevich Saint-Petersburg State University of Telecommunications (SPbSUT), department of communication networks and data transmission, postgraduate; al-kerea.zah@sut.ru

A.S.A. Muthanna, SPbSUT, department of communication networks and data transmission, professor, Dr.Sci.(Tech.); muthanna.asa@sut.ru

A.E. Koucheryavy, SPbSUT, head of the department of the telecommunication networks and data transmission, professor, Dr.Sci.(Tech.); akouch@sut.ru

UDC 621.391
DOI: 10.34832/ELSV.2025.72.10.006

Abstract The paper is devoted to the evolution of communication network architecture in the context of the convergence of space, air, land and underwater segments, as well as the introduction of distributed intelligence in 6G networks. An intelligent architecture of a hybrid algorithm based on particle swarm optimization (PSO) and genetic algorithms (GA) is proposed. The proposed model improves resource allocation, increases energy efficiency and reduces latency. Simulation results show that the proposed scheme provides 75% reduction in power consumption and 50% reduction in latency, making it viable for low-latency and energy-efficient services. The proposed solution is a potential approach to designing communication systems in smart cities, industrial automation and telepresence.

Keywords: 6G, mobile edge computing, fog computing, quality of service, artificial intelligence, SDN, PSO-GA.

For citation: Al-Kerea, Z.A.H. Architectural evolution of 6G networks: distributed intelligence and convergence of space, air, ground and underwater communication systems / Z.A.H. Al-Kerea, A.S.A. Muthanna, A.E. Koucheryavy // Electrosvyaz. – 2025. – No. 10. – P. 63-71. (in russian)

Fundamentals of the development and improvement of models and algorithms for designing LTE-1800 TDD communication networks

D.P. Lobeev, Emperor Alexander I St.Petersburg State Transport University, postgraduate; lobeev1@mail.ru

K.Z. Bilyatdinov, State University of Aerospace Instrumentation (SUAI), department of innovation and integrated quality systems, professor, Dr.Sci.(Tech.), Ph.D.(Mil.); inib@pgups.ru

UDC 654.16
DOI: 10.34832/ELSV.2025.72.10.007

Abstract. The article discusses an algorithm for applying design models for digital LTE-1800 TDD standard railway radio communication systems at the intersection of adjacent networks. The main task is to ensure continuous and stable operation of the system in the presence of mutual electromagnetic interference. A set of design models for digital systems of technological railway radio communication in conditions of intersection of adjacent LTE-1800 TDD networks is proposed, including mathematical and software analysis methods that allow optimizing network parameters to solve the problems of frequency-territorial planning and electromagnetic compatibility assessment.

Keywords: LTE-1800 TDD, digital technological radio communication systems, electromagnetic compatibility, EMC, radio communications, railway transport.

For citation: Lobeev, D.P. Fundamentals of the development and improvement of models and algorithms for designing LTE-1800 TDD communication networks / D.P. Lobeev, K.Z. Bilyatdinov // Electrosvyaz. – 2025. – No. 10. – P. 72-77. (in russian)

Multidimensional constellations for enhanced spectral efficiency

M.G. Bakulin, Moscow Technical University of Communications and Informatics (MTUCI), associate professor, Ph.D.; m.g.bakulin@gmail.com

V.B. Kreyndelin, MTUCI, professor, Dr.Sci.(Tech.); vitkrend@gmail.com

A.A. Reznev, MTUCI, associate professor, JSC NTC Atlas, deputy director, Ph.D.; andrey.reznev@gmail.com

UDC 621.396
DOI: 10.34832/ELSV.2025.72.10.008

Abstract. This paper addresses the problem of enhancing spectral and energy efficiency in digital communication systems through multidimensional QAM constellations that generalize Discrete Faster-Than-Nyquist (DFTN) signaling. It is shown that DFTN signals constitute a special case of multidimensional modulation formed by linear transformation of one-dimensional constellations. A gradient-based optimization method is proposed to minimize an upper bound on the bit error probability by iteratively adjusting signal point coordinates in multidimensional space with an adaptive step size. The algorithm exhibits robust convergence to the global minimum even from random initial conditions. Simulation results demonstrate that optimized multidimensional constellations achieve up to 1.3 dB energy gain over QPSK at identical spectral efficiency. Compared to conventional DFTN schemes, an additional gain of approximately 3 dB is obtained at a spectral efficiency of 3 bits/s/Hz. Furthermore, the proposed approach enables fine-grained, continuous adjustment of spectral efficiency, making it highly promising for adaptive communication systems, including 6G technologies.

Keywords: DFTN, multidimensional constellations, spectral efficiency, energy efficiency, QAM, intersymbol interference, signal optimization.

For citation: Bakulin, M.G. Multidimensional constellations for enhanced spectral efficiency / M.G. Bakulin, V.B. Kreyndelin, A.A. Reznev // Electrosvyaz. – 2025. – No. 10. – P. 78-87. (in russian)

Modeling of interdependencies of resonant oscillation parameters in linear filtration

S.A. Yasinskii, CJSC “Institute of Telecommunications”, leading specialist, associate professor, Dr.Sci.(Tech.); yasinsky777@mail.ru

UDC 621.391
DOI: 10.34832/ELSV.2025.72.10.009

Abstract. The article presents the results of a scientific study on the formation of a mathematical apparatus for modeling the interchangeability of frequency parameters of resonant oscillatory circuits in linear filtering, taking into account the development of approaches for implementing mathematical models based on their representation in the form of quadratic equations, average values, and trigonometric functions in relation to each other. It is proposed that, in addition to the five frequency parameters commonly used in the theory of linear filtering, three additional parameters should be introduced for further research in order to implement band-pass filters with controlled bandwidth.

Keywords: band-pass filter parameters, controlled bandwidth, mathematical models, trigonometric functions, average numbers.

For citation: Yasinskii, S.A. Modeling of interdependencies of resonant oscillation parameters in linear filtration / S.A. Yasinskii // Electrosvyaz. – 2025. – No. 10. – P. 88-92. (in russian)