Actualization of Parameters of Adaptive SDR-equalizer of Wideband HF Radio Channels to Effectively Correct for Frequency Intramode Dispersion

State-of-the-art development of HF radio communication systems follows the idea of significant spreading the bandwidth of variable ionospheric radio channels. In this case, the topical scientific and technical problem is to overcome the negative effect of the frequency intramode dispersion of the medium. For these purpose, we tackled the problem of increasing the efficiency of the channel adaptive SDR-equalizer operating under the various geophysical conditions of the mid-latitude radio propagation path Cyprus-to-Yoshkar-Ola. The following operation modes of the SDR-equalizer were considered: periodic channel testing; estimating the SDR-equalizer parameters and training the SDR-equalizer. For experimental implementation of the testing mode, we developed a physical model of a communication HF signal with a wideband fast frequency hopping. There were experimentally determined: the minimum required bandwidth of the partial subchannel; the number of subchannels to correct for dispersion in 1 MHz channels. In addition to this, there are presented data on the influence of diurnal variations of the ionosphere on the SDR-equalizer parameters.