Мониторинг спектра помех и доступности КВ-радиоканалов с полосами 3…24 кГц
Authors: Иванов Д.В. , Иванов В.А. , Рябова Н.В. , Бельгибаев Р.Р. , Чернядьев А.В. 
Published: February 2025

Развиты методики и алгоритмы определения доступности КВ-радиоканалов с различными полосами 3…24 кГц для прогноза эффективности передачи информации в декаметровом диапазоне. На базе технологии SDR разработан лабораторный образец программно-аппаратного комплекса для реализации подхода спектрального мониторинга. Проведены круглосуточные экспериментальные исследования в наиболее сложной помеховой обстановке: промышленная зона, плотная городская застройка, время года – период летнего солнцестояния. Получены частотные диапазоны наиболее доступных радиоканалов в зависимости от времени суток, а также экспериментальные оценки их минутной доступности.

Currently, HF radio communication is used by civil, industrial, military services and organizations. HF communication systems have a number of advantages, such as: many uses or applications, relatively low cost, large coverage area, which is important for communication in remote areas (mountains, sea, etc.). At the current level of knowledge in the field of wireless communication, there have been created methods that allow to overcome the influence of the negative effects of the HF radio channel on the data transmission, however, with various performance. They imply the use of the sounding mode for multiple channels in the operation of HF communication systems, as well as the use of OFDM signals that exhibit resistance to intersymbol interference. Since the quality of communication is determined by the signal-to-noise ratio (the ratio of signal energy to the spectral density of interferences in the channel), there have been developed cognitive radio methods for HF communications, taking into account the negative effects of intermode dispersion and channel occupancy with interferences. This allows to establish the channel availability. The urgency of the approach is especially high when solving the problem of significant increasing the bandwidth of HF communication (up to 120,000 bps) by spreading the channel bandwidth by a multiple of 3 kHz up to 24 kHz. The need to introduce additional operation modes for HF communication systems requires the development and widespread use of software-defined radio (SDR) technology, as well as the creation of special software with elements of intelligent technologies, such as: technology of machine learning (ML) for the transformation of communication systems to AR (Adaptive Radio), CR (Cognitive Radio) and IR (Intelligent Radio). So, the problem of increasing the data rate in the HF band within the framework of CR and SDR technologies requires the development of methods and algorithms for the introduction of technology for machine learning of communication systems, as well as the creation of laboratory equipment. The aim of the research: development of methods, algorithms and hardware implementation of a laboratory facility for monitoring the interference spectrum in the HF band at different (3 kHz, 6 kHz, 9 kHz, 12 kHz, 18 kHz, 24 kHz) resolution, as well as their experimental verification in a challenging urban reception conditions. Tackled tasks: development of the method, algorithms for the spectral estimation of the availability of radio channels occupied with interferences; creation a laboratory facility for monitoring the spectrum of interferences at HF frequencies based on the software-defined radio technology; experimental verification of the developed method and algorithms in the most difficult reception case - interference environment. Conclusion. A laboratory facility of a software hardware complex developed on the basis of SDR technology for monitoring the interference spectrum in the HF band for radio channels of 3 kHz to 24 kHz width is presented. A scientific statement of methods for estimating and analyzing the availability of such channels for operating frequencies of tactical and strategic communications is given. Experimental verification of methods, algorithms and hardware, carried out during the month of the summer solstice (June) in a challenging urban interference environment, showed that with an increase in the channel bandwidth, their overall availability decreases both in the day and at night. There are presented figures showing that spectral monitoring, implemented on the basis of developed methods and algorithms allows to find available radio channels of tactical and strategic communication systems almost around the clock when operating with low-power signals, even in a challenging interference conditions typical for the cities.