2022

Постійне посилання на фонд

https://ela.kpi.ua/handle/123456789/50069

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Перегляд 2022 за Ключові слова "621.391"

Зараз показуємо 1 - 4 з 4
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    Development of the concept for the computational resources management software in the customer service systems
    (National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", 2022) Skulysh, Mariia; Pastrana Brincones, José Luis; Parhomenko, Dmytro
    Background. To date, there is no customer service system that does not involve information and computer systems. One of the most important issues in ensuring the reliability and reliability of such systems is the task of dynamic scaling and providing the required amount of computing resources at any time. This study was focused on the planning and deployment of computing infrastructure that is able to respond to significantly increased volumes of request flows, changes in the dynamics of load intensity, strict requirements for the quality of their service, etc. Objective. The purpose of the paper is to create a concept of virtual computing space to meet the needs of distributed customer service system, which takes into account the peculiarities of service, the computing node load nature, service quality requirements, and provides energy efficient. Developed models, methods will control the performance of distributed computing infrastructure and flow maintenance processes, reduce downtime of computing resources and provide services to end users at a given level of quality. Methods. Analysis of the operation of the node load assessment mechanism, which consists in a dynamic change in the intensity of control of the state of function nodes, showed the effectiveness of planning for a group of computing nodes.. Results. The proposed approach to managing a heterogeneous computation environment to improve the efficiency of the service maintenance process in new generation systems is a unified solution for highly loaded distributed systems. The developed concept made it possible to avoid a decrease in the quality of service during surges of congestion and to maintain the indicators of the quality of service at a given level, provided that the resource utilization ratio is kept within the given limits Conclusions. In summary, a mathematical model of the problem of determining the maximum allowable load volume with a QoS level guarantee for a service node in a heterogeneous telecommunications environment was proposed.
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    New composite Barker codes, Gold codes and Kasamisequences in broadband signal synchronization systems
    (National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", 2022) Maksymov, Volodymyr; Gatturov, Viktor; Khrapovytsky, Igor
    Background. Currently, noise-like signals (NLS) are widely used, which provide high noise immunity of broadband communication systems (BSS) when transmitting confidential information in an open radio channel, especially in emergency situations. Increasing the efficiency of the NSS is possible with the use of more advanced code structures, in particular, new methods for constructing Barker code sequences used in wireless communication systems with direct sequence spread spectrum technology. Objective. The aim of the work is to study new composite codes of Barker, Gold and Kasami as synchronization signals of the BSS using simulation. Methods. Analytical calculation methods are used, as well as simulation modelling in the MatLab software package. Results. Modelling in the MatLab environment of new composite Barker codes, Gold codes and Kasam isequences as synchronization signals of the BSS showed that the composite sequences of Barker 49 and 77 in the range of SNR change from 0dB to 30dB are more resistant to interference compared to Kasami-63 and Gold-63 by (0,35 – 22,10)%. Conclusions. Modelling in the MatLab software package showed a greater noise immunity of the new composite Barker codes compared to the Gold and Kasami sequenceswhen used as synchronization signals of the BSS.
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    Protection against the effect of different classes of attacks on uav control channels
    (National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 2022) Kaidenko, Mykola; Kravchuk, Serhii
    Background. Protecting the data link of an unmanned aerial vehicle (UAV) is a top priority for countering attacks on UAVs. In this case, it should be taken into account that even the use of the most protected from the effects of deliberate interference types of modulation with spectrum spread does not guarantee the protection of such a channel. Objective. The vulnerability of UAVs using cyber-attacks on a wireless channel is quite large, its study remains relevant, and therefore further development of complex effective means of countering such cyber-attacks is necessary, which is the purpose of this work. Moreover, the countermeasures presented in the work are based on the use of architectural solutions for building a UAV communication channel, which is different from traditional ones. Methods. Structural-functional methods for constructing a secure wireless system of UAV communication channels are being investigated. Results. A block diagram of the organization of UAV electronic countermeasures has been developed, which shows the data transmission channel from the UAV ground control station, the organization of the jamming channel, and the structure of the signal at the receiver input with all distortions and interference. Interferences that can act as a signal of intentional interference from an electronic warfare station are presented and analysed. An architectural solution is proposed using two channels in different frequency bands for the UAV control channel. A schematic structure of the organization of such a communication channel is presented. An expression is given for the margin of safety of a communication channel against a specific intentional interference. It is shown that the proposed architectural solution will have a similar effect when exposed to structured interference on the communication channel. In the case of the impact of imitation interference, the situation will be ambiguous, so it is very important to correctly determine the channel that is affected by intentional interference. It is shown that to determine the presence of intentional interference, it is necessary to have at least one more degree of freedom, which is necessary for classifying such interference and effectively counteracting it. Such a degree of freedom can be achieved by additional dimensions or architectural solutions for building a communication system. Conclusions. The types of intentional interference that can affect the UAV communication channel, the features of their application, and characteristics to ensure effective electronic protection are presented. Scenarios for counteracting the influence of attacks on UAV control channels are proposed. Scenarios with qualitative estimates are given, on the basis of which algorithms for detecting intentional interference and algorithms for counteracting the influence of such interference on the UAV communication channel can be built. It is assumed that the algorithms use averaged parameters, the length of the averaging interval is chosen as a multiple of the length of one data frame, which makes it possible to exclude from consideration fast fading in the communication channel that occurs in the case of frequency selective channels.
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    Soft frequency reuse for miligation of intercelluler intereference
    (National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", 2022) Papushoi, Olha; Mogylevych, Dmytro
    Background. The appearance of femtocells in LTE networks has provided indoor coverage and overcome large data flows for operators. However, strong interference occurs in neighbouring femtocell users due to the limited available spectrum in cellular networks that transmit data in the same radio range. In densely deployed environments, interference issues in single channel femtocells cause significant performance degradation. In this study, we mitigate inter-cell interference in femtocell networks by combining femtocells as a result of common interference and soft frequency reuse in downlink and uplink by moving and exchanging interfering physical blocks. Objective. The purpose of the paper is to improve the efficiency of ensuring the quality of services in wireless networks by reducing any interference due to the distribution of traffic, which is able to provide uninterrupted connection to the user. Methods. Enabling conditions for inter-cell interference mitigation in LTE-based femtocell networks with soft frequency reuse. Results. Interference is a key issue in the deployment of LTE femtocells. Closely located femtocells interfere with each other if they transmit on the same frequency. Therefore, crossing femtocells and enabling them to allocate resources and reuse soft frequencies effectively reduces interference and prevents the loss of network resources. The scheme is triggered whenever the user's femto equipment experiences strong interference from neighbouring femtocells. By assigning a separate set of physical resource blocks to users at the edge of the cell, our scheme significantly reduces interference, which automatically increases cell throughput. The simulation results show the advantages of applying our scheme, in particular, the interference of the user's femto-equipment is reduced by 14% and the throughput is improved by 25%. That is, we observe a significant improvement in the performance of femtocells. Conclusions. A femtocell crossing scheme with soft frequency reuse is presented to reduce interference between femtocells of LTE networks, which allows effectively ensuring the quality of service transmission in wireless networks by reducing interference and increasing performance through traffic distribution.