V.A. Ivanov1, V.V. Pavlov2, M.I. Ryabova3

1-3 Volga State University of Technology (Yoshkar-Ola, Russia)

1 IvanovVA@volgatech.net; 2 PavlovVV@volgatech.net; 3 RyabovaMI@volgatech.net

The development of conceptual and theoretical foundations for improving the efficiency of broadband composite ionospheric channels used for long-range HF radio communication through a new approach to sensor diagnostics based on artificial intelligence methods is an important contemporary research problem. Mathematical modeling was used to determine the effect of receiving antennas on the availability of composite channels and the data rates achieved by different HF communication system modems. An experimental testing method was developed, and experimental studies were conducted to validate its effectiveness in assessing the effect of receiving antennas on signal-to-noise ratio (SNR) gain, taking into account the sporadic E-layer geophysical phenomenon. Based on the experimental data, the performance gain of multi-rate modems using log-periodic (LPA) and vertical monopole (VPA) antennas was evaluated.

The purpose of this study is to analyze theoretical and experimental estimates of the effect of receiving-antenna type on the energy characteristics of long-haul HF communication channels, their overall availability, and the data transfer rates of modern modems under conditions associated with the ionospheric geophysical phenomenon known as the sporadic E layer (Es).

Results: An experimental testing method was developed, and experimental studies were conducted to validate its effectiveness in assessing the effect of receiving antennas on the signal-to-noise ratio. Based on the experimental data, the performance gain of multi-rate modems used in modern HF communication was evaluated. Specific sporadic E-layer conditions were identified to enable a qualitative assessment of the effect of widely used HF antennas on the energy characteristics of a communication link approximately 1,000 km in length. The sporadic E layer was considered as a specific geophysical condition governing signal propagation in the ionosphere.

Using the sensor-diagnostics method and the software-defined radio (SDR) system developed at Volga State University of Technology, the angular-frequency and energy characteristics of the channel were obtained for a 790-km mid-latitude propagation path. These characteristics show that, when an LPA-type antenna is used for reception instead of a VPA-type antenna, the SNR gain at operating frequencies in the range of 18.5–23.3 MHz reaches 5–10 dB for single-hop sporadic-E propagation. It was found that this energy gain enables modern HF communication modems to increase the data transfer rate by a factor of 1.5–4 on propagation paths of approximately 1,000 km under sporadic-E conditions.

Practical significance: The conclusions presented in this study can be regarded as scientific and technical recommendations for the practical application of the results to improve the efficiency of long-range HF radio communication.

Ivanov V.A., Pavlov V.V., Ryabova M.I. Effect of receiving antennas used on availability of long-range HF channels and data transfer rate // Radiotekhnika. 2026. V. 90. № 8. P. 160−173. DOI: https://doi.org/10.18127/j00338486-202608-15

1. Ivanov V.A., Ivanov D.V., Ryabova N.V., Carev I.E. Chislennye i polunaturnye issledovaniya funkcii rasseyaniya uzkopolosnyh dekametrovyh radiokanalov. Elektromagnitnye volny i elektronnye sistemy. 2009. T. 14. № 8. S. 46-54 (in Russian).
2. Ivanov D.V., Ivanov V.A., Ryabova N.V., Elsukov A.A. Aktivnyj i passivnyj sensory dlya diagnostiki kvazizenitnyh ionosfernyh kanalov KV-svyazi. Fizika volnovyh processov i radiotekhnicheskie sistemy. 2023. T. 26. № 4. S. 60-67 (in Russian).
3. Ivanov D.V. Metody i matematicheskie modeli issledovaniya rasprostraneniya v ionosfere slozhnyh dekametrovyh signalov i korrekciya ih dispersionnyh iskazhenij. Monografiya. Joshkar-Ola: MarGTU. 2006. 268 s. (in Russian).
4. Ryabova N.V. Diagnostika i imitacionnoe modelirovanie pomekhoustojchivyh dekametrovyh radiokanalov. Monogra-fiya. Joshkar-Ola: MarGTU. 2003. 291 s. (in Russian).
5. Arthur P.C., Maundrell M.J. Multi-dimensional HF modem performance characterizations. 7-th International Conference on HF Radio Systems and Techniques. 1997. № 411. P. 154-158.
6. Ivanov V.A., Ryabova N.V., Pavlov V.V. Issledovanie napravlennosti KV-antenn dlya zondirovaniya ionosfery po vsem azimutal'nym napravleniyam v usloviyah razmeshcheniya nad real'noj poverhnost'yu Zemli. Vestnik MarGTU. Ser. Radiotekhnicheskie i infokommunikacionnye sistemy. 2010. № 2. S. 36-52 (in Russian).