radio frequency spectrum
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Author(s):  
V. S. Lazorenko ◽  
О. V. Plygunov

The article presents scientific and technical proposals on the possibility of joint use of radio frequency spectrum of the fifth-generation mobile radio communication means and existing departmental radio-electronic facilities. On the basis of the load analysis, using the method of theoretical assessment of electromagnetic compatibility, the norms of territorial diversion between radio means are obtained. On the basis of the results of the calculations, it is possible to determine the subbands in which the joint use of radio means is possible, subject to optimization of the frequency-territorial plan and implementation of technical and organizational measures to ensure electromagnetic compatibility.


Author(s):  
В.С. РЕДЬКОВИЧ ◽  
Е.Л. ПУСТОВОЙТОВ

Приводятся результаты исследования возможности увеличения эффективности использования радиочастотного спектра более чем в два раза за счет использования нескольких (N>2)радиосигналов с неортогональными поляризациями,передаваемых на общей несущей частоте. Предложены метод выявления такой возможности для заданной комбинации поляризаций радиосигналов, а также структурная схема и процедура определения параметров устройства поляризационного разделения радиосигналов на приемной стороне. Выполнен детальный анализ определения оптимальных коэффициентов элементов системы поляризационного разделения на приемной стороне четырех радиосигналов с учетом иррациональности коэффициентов анализируемой системы линейных уравнений. The results of the study of the possibility of increasing the efficiency of using the radio frequency spectrum by more than twice due to several (N>2) non-orthogonal polarizations of carrier radio signals are presented. The method to determine such possibility for any given set of polarizations, as well as a block diagram and a procedure for determining the parameters of a device for polarization separation of radio signals on the receiving side are proposed. The detailed analysis of the determination of optimal coefficients of elements of polarization separation system on receiving side of four radio signals is performed taking into account the irrationality of coefficients of analyzed linear equation system.


Entropy ◽  
2021 ◽  
Vol 23 (12) ◽  
pp. 1611
Author(s):  
Gianmarco Baldini ◽  
Jean-Marc Chareau ◽  
Fausto Bonavitacola

Spectrum sensing is an important function in radio frequency spectrum management and cognitive radio networks. Spectrum sensing is used by one wireless system (e.g., a secondary user) to detect the presence of a wireless service with higher priority (e.g., a primary user) with which it has to coexist in the radio frequency spectrum. If the wireless signal is detected, the second user system releases the given frequency to maintain the principle of not interfering. This paper proposes a machine learning implementation of spectrum sensing using the entropy measure as a feature vector. In the training phase, the information about the activity of the wireless service with higher priority is gathered, and the model is formed. In the classification phase, the wireless system compares the current sensing report to the created model to calculate the posterior probability and classify the sensing report into either the presence or absence of wireless service with higher priority. This paper proposes the novel application of the FDE measure recently introduced in the research community as a feature vector to build the model and implement the classification. An improved implementation of the FDE (IFDE) is used to enhance the robustness to noise. IFDE is further enhanced with an adaptive method (AIFDE) to automatically select the hyper-parameter introduced in IFDE. Then, this paper combines the machine learning approach with the entropy measure approach, which are both recent developments in spectrum sensing research. The approach is compared to similar approaches in literature and the classical energy detection method using a generated radar signal data set with different conditions of SNR(dB) and fading conditions. The results show that the proposed approach is able to outperform the approaches from literature based on other entropy measures or the ED in a consistent way across different levels of SNR and fading conditions.


2021 ◽  
Vol 1199 (1) ◽  
pp. 012052
Author(s):  
J Husár ◽  
L Knapčíková ◽  
S Hrehová

Abstract People have been dealing with the correct identification of objects for a long time. In industry, we cannot avoid this area, whether it is to identify people, semi-finished products or final products. Therefore, this article deals with the design of a multifrequency RFID system for industry 4.0. The idea of the article is to implement one type of identification technology for tracking objects using the radio frequency spectrum at different wavelengths. We have based our design on the built industrial-assembly line in the SmartTechLab laboratory, where we have implemented LF, HF and UHF systems connected by an industrial PLC into a complex system. In this article, we gradually focus on the selection of RFID systems, their cooperation and the design of connection to one portable box. Using an RFID box, we can monitor different types of objects and verify RFID reading using a single reading device or by creating portal RFID gateways. The implemented system consists of four middleware and four independent antennas that can cooperate. For proper operation, there is necessary implement not only hardware but also necessary software. The system can identify RFID tags in the range of 1 cm to several meters. Also, the advantage of the design is that it identifies all types of tags (industry, label, ceramic, laundry, paper). One of the main benefits of the design is modularity, mobility and the creation of a robust design that can be used for measurements in companies and also for educating students in laboratory conditions. The whole system is designed to meet the requirements of Industry 4.0 and improve the competitiveness of businesses.


2021 ◽  
Vol 5 (2) ◽  
pp. 73-80
Author(s):  
Ari Endang Jayati ◽  
Wahyu Minarti ◽  
Sri Heranurweni

The radio frequency spectrum constitutes a limited and strategic natural resource with high economic value, so it must be managed effectively and efficiently to obtain optimal benefits by observing national and international legal principles. Radio Community Broadcasting Institution uses limited frequency allocation in three channels, namely, in the frequency channels 202 (107.7 MHz), 203 (107.8 MHz), and 204 (107.9 MHz), with limited transmit power and area coverage. The problem in this research is the frequency overlap with other community radios in an area. The issue raised is whether it is possible to establish a new community radio in the Batang Regency area by paying attention to existing radios that have licenses in districts/cities that are in the area directly adjacent to Batang Regency by considering the limited allocation of radio frequency channels community, without the occurrence of radio frequency interference with other community radios. The purpose of this research is to solve these problems. It is necessary to have a policy in determining radio frequency users to get good quality radio broadcast reception. The method used is to analyze the frequency determination technique based on the interference analysis on other community broadcasters. By using the Radio Mobile Software for frequency repetition simulation, in this research, the results show that Batang FM Community Radio does not allow to get frequency channels for community radio operations. After all, it interferes with the Service Area of ​​Soneta FM Radio in Pekalongan City because it does not meet the requirements for determining the frequency channel = Eu> NF, namely the Nuisance Field (NF) value of 109.7 dB is greater than the Minimum Usable Field strength (Eu) of 66 dB. In comparison, Limpung FM Radio gets radio frequency on channel 203 (frequency 107.8 MHz) because it meets the requirements for determining the frequency channel = Eu> NF, namely the Minimum Usable Field strength (Eu) 66 dB greater than the Nuisance Field (NF) of 55.7 dB.


2021 ◽  
Vol 11 (18) ◽  
pp. 8288
Author(s):  
Davide Margaria ◽  
Andrea Vesco

The protection of satellite-derived timing information is becoming a fundamental requirement in Industry 4.0 applications, as well as in a growing number of critical infrastructures. All the industrial systems where several nodes or devices communicate and/or coordinate their functionalities by means of a communication network need accurate, reliable and trusted time synchronization. For instance, the correct operation of automation and control systems, measurement and automatic test systems, power generation, transmission, and distribution typically require a sub-microsecond time accuracy. This paper analyses the main attack vectors and stresses the need for software integrity control at network nodes of Industry 4.0 applications to complement existing security solutions that focus on Global Navigation Satellite System (GNSS) radio-frequency spectrum and Precision Time Protocol (PTP), also known as IEEE-1588. A real implementation of a Software Integrity Architecture in accordance with Trusted Computing principles concludes the work, together with the presentation of promising results obtained with a flexible and reconfigurable testbed for hands-on activities.


Author(s):  
Е.Е. Гринин ◽  
А.Б. Антиликаторов ◽  
О.В. Четкин ◽  
И.А. Новикова

Основной темой являются некоторые из алгоритмов сканирования радиоспектра и обнаружения сигналов в системе когнитивного радио, а также само когнитивное радио. Данная тема является актуальной, так как применение широкополосных каналов является одним из вариантов организации связи, но при этом возникают некоторое трудности. Например, из-за большого числа пользователей необходимо более рационально использовать спектр радиочастот. Рассматриваются основные аспекты обнаружения сигнала в узкополосных и широкополосных диапазонах. Рассказывается о недостатках адаптивных алгоритмов обнаружения, основанных на стандартных законах распределения. Приведены примеры как параметрических, так и непараметрических алгоритмов обнаружения. Подробно описывается алгоритм, основанный на критерии Уилкоксона. При помощи критерия Неймана-Пирсона можно сравнивать обнаружители между собой. Сделаны выводы о целесообразности применения для мониторинга радиоспектра непараметрических алгоритмов обнаружения. Для случая постоянного положительного сигнала на фоне гауссовской помехи сравнение значений асимптотической относительной эффективности для критерия Уилкоксона со значением линейного обнаружителя составляет порядка 0,955. Это значение говорит о том, что оба обнаружителя практически не уступают друг другу в таких условиях The article discusses some of the algorithms for scanning the radio spectrum and detecting signals in the cognitive radio system, as well as the cognitive radio itself. This topic is relevant since the use of broadband channels is one of the options for organizing communication. Due to a large number of users, it is necessary to more rationally use the radio frequency spectrum. We considered the main aspects of the detection of the signal in narrowband and broadband bands. We described the lack of adaptive detection algorithms based on the standard distribution laws. We give examples of both parametric and non-parametric detection algorithms. We described the algorithm based on Wilcoxon's criteria in detail. Using the Neuman-Pearson's criterion, you can compare the detectors among themselves. We made conclusions about the feasibility of application for monitoring the radiospectract of non-parametric detection algorithms. For the case of a constant positive signal against the background of Gaussian interference, comparing the values of asymptotic relative efficiency for the Wilcoxon’s criterion with the value of the linear detector is about 0.955. This value suggests that both detectors are practically inferior to each other in such conditions


2021 ◽  
Vol 11 (9) ◽  
pp. 4083
Author(s):  
Sung-woo Cho

Radio-frequency spectrum resources are finite and scarce, but their demand is increasing exponentially every year. Therefore, wireless network resources are too expensive to be wasted. To avoid waste, pricing techniques can efficiently control resource usage and manage user needs in networks. This study focuses on QoS-aware pricing for usage-based mobile Internet access charging. Specifically, I propose a heuristic algorithm for priority pricing with multiple service levels. The proposed algorithm is built on top of the existing equilibrium analysis methods. While being extensively studied for optimal price selection, the equilibrium methods make a few unrealistic assumptions, and so my methods adjust the solutions of the equilibrium methods to account for distortions that the real world creates. The evaluation results indicate that multiple equilibrium prices may exist, and the proposed scheme produces a pricing plan that is substantially more effective than existing equilibrium methods.


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