D.V. Ivanov1, V.A. Ivanov2, N.V. Ryabova3, N.A. Konkin4, A.A. Chernov5

1-5 Volga State University of Technology (Yoshkar-Ola, Russia)

1 IvanovDV@volgatech.net; 2 IvanovVA@volgatech.net; 3 RyabovaNV@volgatech.net;
4 KonkinNA@volgatech.net; 5 ChernovAA@volgatech.net

For the organization of highly reliable low-speed HF communication often used methods of spacing and especially the method of significant frequency-temporal spacing. In this case, the message is periodically repeated in channels occupying a band exceeding the transparency range of the ionospheric communication line. However, as studies have shown, its exceeding leads to deterioration of reliability at reception due to the transmission of bits of the message in obviously inaccessible channels that are outside its limits. To improve reliability, more accurate information about the current values of the useful frequency range boundaries is required, which is possible when using sensor diagnostics and prediction methods for this purpose. It is known? that the maximum usable frequency (MUF) has a higher variability, so it is for it that this task is the most relevant.

The purpose of the study is to develop diagnostic and prediction methods to create a cognitive approach for adaptive estimation of the upper boundary of the transparency bandwidth of an ionospheric HF communication line.

In the paper the principle of experimental automatic estimation of MUF as a result of diagnostics of the SW radio line is formulated. It is shown that the use of the experimental frequency dependence of the delay profile of the power profile of the difference probing signal for adjacent radio channels and the criterion for selecting the MUF, allows to automatically obtain the instantaneous current values of MUF, simultaneously with the probing session of the ionospheric radio link. Theoretical substantiation of the approach to MUF forecasting is given and the method of dividing its daily temporal variations into trend values and residual component is developed. The criterion of the regular component of MUF(t) variations is formulated. The theoretical substantiation of the randomness of the residual component of the time series of the MUF predictor function is given, and the main characteristics of the daily course of the residual component of the MUF are obtained. It is shown that on a large set of experimental results from the VSUT (Volgatech) Data Bank, the standard deviation of the random component does not exceed 100-150kHz.

Practical research: the proposed approach allows to provide practically 100% reliability of short message transmission when using a variable reflective HF radio channel, especially, in the case of application of the method of significant time – frequency spacing of signals. The approach is of particular importance when it is necessary to provide relevant economic structures with highly reliable long-distance communications in emergency situations, as well as for use in remote control and telemetry systems.

This work was supported by the grant 23-19-00145 from the Russian Science Foundation.

Ivanov D.V., Ivanov V.A., Ryabova N.V., Ovchinnikov V.V., Konkin N.A., Chernov A.A. Prediction of the ionospheric usable bandwidth of a HF radio communication line. Part 1. Theoretical and experimental bases of a new cognitive approach to MUF diagnosis and prediction. Radiotekhnika. 2025. V. 89. № 2. P. 144−158. DOI: https://doi.org/10.18127/j00338486-202502-19 (In Russian)

1. Ivanov D.V., Ivanov V.A., Elsukov A.A., Rjabova N.V. Metodologija i maket programmno-konfiguriruemoj sistemy dlja nizkoskorostnoj peredachi informacii po ionosfernomu radiokanalu s vysokoj nadezhnost'ju. Vestnik Povolzhskogo gosudarstvennogo tehnologicheskogo universiteta. Ser. Radiotehnicheskie i infokommunikacionnye sistemy. 2023. № 3(59). S. 45-57. DOI: 10.25686/2306-2819.2023.3.45 (in Russian).
2. Ivanov D.V., Ivanov V.A., Elsukov A.A., Rjabova N.V., Ovchinnikov V.V., Isaev N.R. Metod i algoritmy avtomaticheskogo obnaruzhenija signala v zadache sensornoj diagnostiki KV-radiokanala. Radiotehnika. 2023. T. 87. № 12. S. 158-170. DOI: 10.18127/j00338486-202312-17 (in Russian).
3. Ivanov D.V., Ivanov V.A., Rjabova N.V., Vedernikova Ju.A., Chernov A.A. Metod sinhronizacii sistem nizkoskorostnoj peredachi telegrafnyh soobshhenij malogo ob'ema na KV-trassah bol'shoj protjazhennosti. Radiotehnika. 2023. T. 87. № 12. S. 6-16. DOI: 10.18127/j00338486-202312-02 (in Russian).
4. Ivanov V.A., Rjabova N.V. Sovremennye podhody v kratkosrochnom prognozirovanii pomehoustojchivyh ionosfernyh radiokanalov dlja dekametrovyh telekommunikacionnyh sistem. Vestnik Marijskogo gosudarstvennogo tehnicheskogo universiteta. Serija: Radiotehnicheskie i infokommunikacionnye sistemy. 2007. № 1 (1). S. 23-34 (in Russian).
5. Barclay L.W. Propagation of Radiowaves. IET. 2003. 460 p.
6. Ivanov V.A., Rjabova N.V., Bastrakova M.I. Metodika opredelenija pomehoustojchivosti ionosfernyh radiokanalov s pomoshh'ju LChM-ionozonda s SDR priemnikom. Sistemy sinhronizacii, formirovanija i obrabotki signalov. 2016. T. 7. № 4. S. 22-24  (in Russian).
7. Rjabova N.V. Diagnostika i imitacionnoe modelirovanie pomehoustojchivyh dekametrovyh radiokanalov. Joshkar-Ola: Povolzhskij gosudarstvennyj tehnologicheskij universitet. 2003. 291 s. (in Russian).
8. Kremer. N.Sh. Teorija verojatnostej i matematicheskaja statistika. IZd. 3-e, pererab. i dop. M.: JuNITI-DANA. 2017. 551 s. (in
   Russian).
9. Harris F.Dzh. Ispol'zovanie okon pri garmonicheskom analize metodom diskretnogo preobrazovanija Fur'e. Trudy IIJeT. 1978. T. 66. № 1 (in Russian).
10. Ivanov D.V., Ivanov V.A., Elsukov A.A., Konkin N.A. Metod odnovremennogo mnogochastotnogo testirovanija ionosfernyh KV-radiokanalov pri distancionnom upravlenii obrabotkoj i analizom dannyh. Vestnik Povolzhskogo gosudarstvennogo tehnologicheskogo universiteta. Ser. Radiotehnicheskie i infokommunikacionnye sistemy. 2021. № 4(52). S. 6-23. DOI: 10.25686/2306-2819.2021.4.6  (in Russian).