2687-0517 Computing, Telecommunication and Control 19 3 2026 1-147
RAR RUS 7-17 0000-0003-0726-6613 Peter the Great St. Petersburg Polytechnic University Pavlov Vitalii pavlov_va@spbstu.ru
St. Petersburg, Russian Federation
 0009-0008-1065-6798 Tsytsulin Aleksandr tsysulin@niitv.ru 0000-0001-5282-2506 Savischenko Nikolay Russian-Armenian University Avetisyan Vaan avahan@mail.ru
Yerevan, Republic of Armenia
 Identification of spacecraft at close range using depth maps The article addresses the problem of automatic detection, segmentation, and classification of spacecraft using depth maps. The study was based on synthesized semi-natural data, which made it possible to simulate various orbital imaging conditions and to provide accurate ground-truth annotations for the quantitative evaluation of algorithms. Due to the instability of texture and color features under real space conditions, the geometric structure of objects is proposed as a key invariant feature. To solve the detection problem, a multi-stage algorithm has been developed, which includes adaptive histogram equalization, local threshold segmentation, morphological processing, and filtering of false contours based on geometric criteria. To classify spacecraft, deep neural networks of the ResNet family were used in two configurations: based on optical images alone and based on combined data (image + depth map). Experiments on a synthetic dataset of 19440 images showed that the proposed algorithm significantly outperforms the SAM 3 model in terms of detection accuracy (Precision 0.917 vs 0.171), ensuring a low level of false positives. The multimodal approach to classification achieved an accuracy of 99.9% (ResNet-152 model), confirming the effectiveness of using depth maps for reliable recognition of spacecraft under near-real space imaging conditions. 10.18721/JCSTCS.19301 004.932.72 spacecraft synthetic data object detection computer vision depth maps https://infocom.spbstu.ru/article/2026.90.1/
RAR RUS 18-28 0009-0009-6909-9399 National Research University “Moscow Power Engineering Institute”; Moscow Technical University of Communications and Informatics Agamirov Levon itno_agamirov@mail.ru
Moscow, Russian Federation
 0000-0001-9181-7726 Moscow Technical University of Communications and Informatics; Moscow Aviation Institute (National Research University) Agamirov Vladimir avhere@yandex.ru
Moscow, Russian Federation
 0009-0009-6284-515X Slyadnikov Pavel p.e.slyadnikov@mtuci.ru 0000-0002-2851-8472 Moscow Technical University of Communications and Informatics Toutova Natalia e-natasha@mail.ru
Moscow, Russian Federation
 0009-0008-7929-5492 Moscow Technical University of Communications and Informatics Khaush Anton anton.khaush@gmail.com
Moscow, Russian Federation
 Design of an automated freight transportation monitoring system based on internet of things networks using blockchain technology The paper proposes an architecture for an automated freight transportation monitoring system based on blockchain technology. When integrating standard blockchain solutions with Internet of Things (IoT) devices into a unified techno-logical system, it is necessary to minimize direct requests to the main registry (root blockchain). This requirement remains essential even when participants of the distributed network are granted permissions to modify smart contract parameters, thereby reducing the load on the root registry while ensuring a high level of security during data transmission: from sensors to the mobile node and from the mobile node to the root system. The paper presents a comparative analysis of distributed ledger platforms, taking into account regional specifics and the possibility of integrating certified domestic cryptographic information protection tools. A prototype of an end-to-end freight transportation monitoring system has been developed and implemented, providing continuous tracking of cargo conditions sensitive to environmental factors. Simulation results confirm the effectiveness of using smart contracts for automating control procedures and ensuring the immutability of logistics operation data. The proposed architecture enables the development of scalable and secure industrial monitoring networks for logistics companies. 10.18721/JCSTCS.19302 004.8 Internet of Things blockchain smart contract cargo transportation logistics mobile node information security https://infocom.spbstu.ru/article/2026.90.2/
RAR RUS 29-45 0009-0005-6368-0001 Goriunov Maksim goryunov_myu@spbstu.ru Peter the Great St. Petersburg Polytechnic University Konstantinov Andrei andrue.konst@gmail.com
St. Petersburg, Russian Federation
 Novikov Fedor Kernel Regression with Tree-Induced Metrics This paper presents a family of kernel models based on metrics derived from the structure of decision trees and random forests. Unlike the standard random-forest proximity, which only checks whether two observations fall into the same leaf, the proposed metrics also use information about decision paths, the depth of their divergence, and the depth of their lowest common ancestor. A weighted variant with trainable depth-dependent parameters is also introduced. The tree-based metrics are aggregated over a forest and used to construct exponential kernels. They can also be combined with the Euclidean distance in the original feature space. We prove that the resulting kernels are positive semidefinite and can therefore be used in standard kernel methods, including Nadaraya–Watson regression and kernel ridge regression. The proposed models are evaluated on classification datasets and in a controlled source-to-target regression experiment with a limited number of labeled target observations. The results show that information about the internal structure of decision trees can be useful beyond simple leaf coincidence. Several proposed variants improve upon conventional geometric kernels and the standard random-forest proximity kernel, while the best-performing metric depends on the prediction method and the dataset. 10.18721/JCSTCS.19303 004.852 kernel regression decision trees tree-based metrics random forests Nadaraya–Watson estimator kernel ridge regression https://infocom.spbstu.ru/article/2026.90.3/
RAR RUS 46-56 0000-0001-8553-640X Kudayeva Fatimat kfatimat@yandex.ru 0009-0009-4666-3356 Bitsuev Timur timur_kbsu@mail.ru Hybrid intelligent system for stratifying the risk of coronary heart disease The article proposes a hybrid intelligent system for stratifying the risk of coronary heart disease (CHD). It includes ensemble forecasting, natural language processing, and explainable AI technologies. It is demonstrated that the integration of structured clinical features and unstructured text data improves the accuracy of CHD risk assessment compared to the traditional SCORE2 scales. On test datasets, high values of AUC-ROC and F1-score were achieved, while the interpretability of the predictions is ensured by constructing waterfall plots that reflect the contribution of key risk factors. The developed software package will be useful in cardiology for supporting clinical decision-making. 10.18721/JCSTCS.19304 004 hybrid intelligent system ensemble machine learning cardiovascular outcome predic-tion natural language processing artificial intelligence SHAP analysis clinical decision support https://infocom.spbstu.ru/article/2026.90.4/
RAR RUS 57-69 0009-0001-8226-6288 Mironov Kirill Morozov Dmitriy dvmorozov@inbox.ru Pilipko M.M. m_m_pilipko@rambler.ru Stabilized Current Source in 180 nm CMOS This paper presents a comparative analysis of four CMOS stabilized current source architectures: the beta-multiplier, an op-amp-enhanced beta-multiplier, the Nagata current source, and a modified Nagata source with active feedback based on an op-amp. The study focuses on evaluating their performance in terms of thermal stability, dependence on supply voltage and the output noise current spectral density. Analytical considerations were validated through simulation using the Mikron JSC 180 nm 1.8 V CMOS process. The findings reveal the trade-offs between circuit complexity, supply voltage and temperature independence, as well as noise level. The op-amp-enhanced Nagata current source is the best of the considered circuits and has the following characteristics: nominal current 15.14 µA, supply voltage dependence of the reference current 0.1 µA/V, RMS output noise current 63.98 nA (within 0.1 Hz to 1 MHz band), current temperature coefficient 66.15 ppm/°C. This circuit has been chosen for the layout implementation. Layout sizes are 18 × 28 µm. 10.18721/JCSTCS.19305 621.3.049.77 CMOS reference current source output noise current PTAT current CTAT current https://infocom.spbstu.ru/article/2026.90.5/ 57-69.pdf
RAR RUS 70-82 Sizin Ivan beautyjesus9@gmail.com Peter the Great St. Petersburg Polytechnic University Lukin Aleksei lukin@compmechlab.com
St. Petersburg, Russian Federation
 0000-0003-3103-7060 Peter the Great St.Petersburg Polytechnic University Loboda Vera
Polytechnicheskaya, 29, St.Petersburg, 195251, Russian Federation
 Smerdov Rostislav rostofan@gmail.com Electrostatic shunt RF MEMS switch with a floating electrode for S-band applications: architecture and mathematical modeling This paper presents the design and modeling of an electrostatically actuated capacitive shunt RF MEMS switch with a floating electrode for S-band operation. The proposed architecture incorporates a mechanically fixed, electrically floating metal electrode positioned above the signal line and separated from it by a high-k TiO2 dielectric layer. This configuration substantially increases the down-state capacitance and improves signal isolation without requiring extremely small interelectrode gaps. The switch is implemented on a coplanar waveguide and uses an aluminum membrane with meander suspensions and perforation to reduce the effective stiffness, actuation voltage, and switching time. The main electromechanical parameters were evaluated analytically and verified by finite element modeling in COMSOL Multiphysics, while the RF performance was analyzed using electromagnetic simulation in ANSYS HFSS. The final design demonstrates a pull-in voltage of 2.7 V, a closing time of 18 μs, a down-state capacitance of 247 pF, and an up-state capacitance of 9.6 fF. In the 2–4 GHz range, the simulated up-state insertion loss is from –0.012 to –0.14 dB, and the down-state isolation is from –43.3 to –89.75 dB. The results show that the floating-electrode architecture provides a high capacitance ratio and significantly enhances the RF performance of the capacitive shunt MEMS switch. 10.18721/JCSTCS.19306 621.396 RF MEMS switch shunt architecture insertion loss S-parameters floating electrode S-band https://infocom.spbstu.ru/article/2026.90.6/
RAR RUS 83-96 Special Technological Center Ltd. Klimenko Denis d.klimenk0@yandex.ru
St. Petersburg, Russian Federation
 Peter the Great St.Petersburg Polytechnic University Nikitin Aleksandr nikitin@mail.spbstu.ru
Polytechnicheskaya, 29, St.Petersburg, 195251, Russia
 Peter the Great St. Petersburg Polytechnic University Stroganov Alexander lemyr103@gmail.com
St. Petersburg, Russian Federation
 Design of GaAs pHEMT front-end MMIC for downconverter This paper details the design of a multifunctional front-end microwave monolithic integrated circuit (MMIC) intended for downconverter applications in the 1–3 GHz frequency range. The primary objective of this research is to develop a compact, high-performance MMIC that integrates three critical receiver functions – a low-noise amplifier (LNA), a 2-bit digital attenuator, and a single-pole five-throw (SP5T) switch – on a single gallium arsenide (GaAs) pHEMT die using a domestic technological process. The LNA employs a two-stage cascaded common-source configuration with RC-feedback networks to achieve wideband matching and low noise. The digital attenuator is constructed using a bridged T-network for 6 dB attenuation and a Π-network for 12 dB attenuation. The SP5T switch utilizes a series-shunt topology with a five-way combining junction to minimize chip area. Electromagnetic simulation results for the complete front-end demonstrate excellent performance, achieving a gain of no less than 29.9 dB, a noise figure not exceeding 1.21 dB, and an input and output return loss better than –8.4 dB across the operating band. The linearity figures, a P1dB of 20.6 dBm and an OIP3 of 30.1 dBm, confirm its suitability for demanding receiver systems. Furthermore, a comparative analysis against commercial analogues shows that the designed MMIC offers a competitive combination of wide bandwidth, low noise, moderate current consumption (under 85 mA at 5 V), and a compact layout (3.4×3.2 mm), validating its potential as a viable domestic alternative for high-performance microwave modules. 10.18721/JCSTCS.19307 621.372.57 GaAs pHEMT MMIC front-end LNA attenuator SP5T https://infocom.spbstu.ru/article/2026.90.7/
RAR RUS 97-107 Zavialov Sergey S-4849-2017 57191270776 0000-0001-7006-9634 Peter the Great St.Petersburg Polytechnic University Sergey B. makarov_sb@spbstu.ru
Polytechnicheskaya, 29, St.Petersburg, 195251, Russia
 Orlova Anna ovsyannikova_as@spbstu.ru Kuznetsova Alexandra kuznetsova_aa@spbstu.ru Gelgor Alexandr 0000-0001-5282-2506 Savischenko Nikolay Russian-Armenian University Avetisyan Vaan avahan@mail.ru
Yerevan, Republic of Armenia
 Application of optimal amplitude-phase modulation signals in channels with Doppler frequency shift The paper addresses the problem of improving the spectral efficiency of radio communication systems operating in channels with Doppler frequency shift by employing optimal signals with amplitude-phase modulation. The relevance of the study is driven by the need for high data rate transmission in low-Earth orbit satellite communication systems, where conventional signals based on RRC pulses exhibit significant energy losses when the symbol rate is increased. A synthesis technique for optimal shaping pulses is proposed, based on the criterion of out-of-band emission suppression under given constraints on the cross-correlation coefficient that determines the BER performance. A computer simulation model of the transmission channel is developed, taking into account carrier frequency instability, timing synchronization offset, and Doppler shift modeled with time-scale transformation. Numerical simulations for 64APSK constellation and coding rate 4/5 demonstrate that the use of optimal signals with doubled symbol rate provides a spectral efficiency gain of up to 12.7% compared to RRC-based signals when the occupied bandwidth is estimated by the 99% energy concentration criterion. The associated energy penalties range from 3 to 4 dB depending on the satellite elevation angle, which is attributed to the need for wider receiver front-end bandwidth under Doppler-induced spectral distortions. It is shown that the choice of the cross-correlation coefficient enables a trade-off between BER performance and spectral efficiency. The obtained results confirm the feasibility of optimal signals in satellite communication systems with high spectral efficiency requirements and limited link power budgets. 10.18721/JCSTCS.19308 621.391.8 optimal signals APSK Doppler shift spectral efficiency satellite communications FTN DVB-S2X https://infocom.spbstu.ru/article/2026.90.8/
RAR RUS 108-120 0000-0001-6503-826X Chilingarov Artem chilingarov.ao@gmail.com Gelgor Alexandr Russian-Armenian University Avetisyan Vaan avahan@mail.ru
Yerevan, Republic of Armenia
 Adaptive PAPR reduction using tone reservation and clipping in OFDM transmission over fading channels The high peak-to-average power ratio (PAPR) inherent in orthogonal frequency-division multiplexing (OFDM) signals forces the high-power amplifier (HPA) to operate with substantial input back-off (IBO) value, severely degrading transmitter power efficiency. This paper investigates the joint application of adaptive tone reservation (TR) and clipping for PAPR reduction in OFDM transmission over frequency-selective fading channels. The adaptive TR scheme employs channel state information to dynamically allocate reserved tones to subcarriers that experience poor signal-to-noise ratio (SNR) and are therefore of limited utility for data transmission. Four configurations have been systematically compared: a baseline without PAPR reduction, clipping only, adaptive TR only, and the proposed joint adaptive TR and clipping scheme. Simulations for the case of a measurement-based underwater acoustic channel with a hard-limiter HPA model demonstrate that adaptive TR alone achieves a 2.8 dB SNR gain over the baseline at a target bit error rate of 10–3, without introducing in-band distortion. The joint scheme yields a total SNR gain of 4.6 dB, combining the benefits from distortionless peak suppression by TR with the aggressive clipping action. Relative to clipping-only operation, the joint scheme decreases out-of-band emission by 3.5 dB and compresses the 99.5% occupied bandwidth by 40%. These results confirm that the combination of SINR-based adaptive TR and clipping provides simultaneous improvements in power efficiency and spectral containment, making it a compelling solution for communication systems subject to both power and spectral mask constraints. 10.18721/JCSTCS.19309 621.391.8 PAPR tone reservation power allocation adaptive systems out-of-band emission suppression https://infocom.spbstu.ru/article/2026.90.9/
RAR RUS 121-129 Usoltsev Mikhail usol.91@mail.ru Borisovskii Fedor feka09@gmail.com Budanov Dmitriy dmitriy.budanov@gmail.com Application of asynchronous data bypass to increase performance of in-order superscalar RISC-V processor core RISC-V is an open-source architecture that does not require license fees from pro-cessor core vendors. This allowed RISC-V to become widely distributed first in the micro-controller-class processor core market and subsequently in the market of higher-performance devices. Currently RISC-V processor cores with in-order execution, which combine mid-range performance, compactness, and energy efficiency are attracting the most interest from customers. This makes the task of continuing to improve them a highly relevant. This paper explores the application of a microarchitectural modification, asynchronous data bypass, to increase the performance of in-order superscalar RISC-V processor core. Asynchronous data bypass has been made for two pairs of functional blocks: between arithmetic-logic unit (ALU) and ALU, between ALU and branch unit. The main obstacle of implementing asynchronous data bypass is the creation of an extremely long logical path, which leads to violations of timing constraints. To overcome this obstacle, an approach was proposed that involves completely excluding a subset of instructions from asynchronous bypass and separating the logic of the remaining instructions into groups based on the length of the logical path. This approach made it possible to keep the logical path of asynchronous bypass no longer than the longest path of a single execution unit. The results showed that the use of asynchronous bypass can significantly increase the performance of in-order superscalar processor core. At the same time, the area overhead is very low. 10.18721/JCSTCS.19310 004.2 processor core superscalarity in-order asynchronous data bypass logical path https://infocom.spbstu.ru/article/2026.90.10/
RAR RUS 130-147 Peter the Great St. Petersburg Polytechnic University; Lomonosov Moscow State University Razuvaev Daniil Razuvaev_DD@mail.ru
St. Petersburg, Russian Federation; Moscow, Russian Federation
 Multi-Layer Hash Anchoring method with waterfall consensus for fact-oriented blockchain The paper proposes a method based on the ideas of classical Proof-of-Work (PoW) for building a distributed registry (Multi-Layer Hash Anchoring, MLHA) based on redundancy of PoW block headers. Each block contains links to the last blocks of all layers, determined by the number of leading hash zeros, which allows you to highlight the sparse skeleton of the waterfall chain. The properties of the waterfall are investigated: uniqueness, determinism, and logarithmic growth of average length. The criterion for the safe deletion of blocks not included in the waterfall is proved, and the possibility of a trustless audit of deleted data is shown. A consensus mechanism based on a lexicographic comparison of waterfall vectors is proposed, consistent with the principle of maximum performance. A single security window has been introduced linking the network hashrate, the minimum mining complexity and the allowable probability of an attack; an upper bound on this probability has been obtained. The simulation results confirm the theoretical estimates. The method does not require a trusted installation, has post-quantum stability and can be used in lightweight decentralized systems. 10.18721/JCSTCS.19311 004.9:004.94 Proof-of-Work blockchain data compression logarithmic growth consensus waterfall MLHA https://infocom.spbstu.ru/article/2026.90.11/