Use of Sensor Diagnostics of Ionospheric Radio Channels to Adapt the Hf Communication System for Signal Strength and Modem Performance

This study presents a method for adapting highfrequency (HF) communication systems by optimizing radiated power and modem performance based on sensor diagnostics of ionospheric radio channels. The adaptation criterion is the availability of channels with bandwidths in multiples of 3 kHz (up to 8 multiples, i.e., 24 kHz), assessed by the level of concentrated interference. The sensor leverages software-defined radio (SDR) technology for real-time diagnostics. The method was validated through experimental studies in urban reception conditions in Yoshkar-Ola. Results demonstrated diurnal variations in channel availability influenced by different detector thresholds for identifying narrowband interference, correlated with adjustments in transmitted signal power. Experiments showed that increasing the signal power by <tex>$\mathbf{5} \mathbf{- 1 0 ~ d B}$</tex> can enhance modem performance by <tex>$2-4$</tex> times. This effect serves as a criterion for adaptive modem optimization. These findings offer significant opportunities to improve the efficiency of HF communication systems.