Optimal Operating Frequency According to the Maximum Interval of Frequency Fade Correlation in a Single-Beam Decametric Radio Link

Abstract

An analytical method has been developed for determining the dependence of the fading frequency correlation interval in a single-beam decameter radio link on the ratio of the operating frequency to the maximum applicable frequency, the degree of ionospheric diffuseness (the intensity of small-scale irregularities), and the communication range (radio link length). This dependence is obtained as the product of the traditional fading frequency correlation interval in a single-beam decameter radio link by a reduction factor. It is substantiated that as the ratio of the operating frequency to the maximum applicable frequency increases, the value of the traditionally determined fading frequency correlation interval decreases, and the reduction factor increases. The optimal values of the operating frequency (relative to the maximum usable frequency) are established according to the criterion for ensuring the maximum values of the fading frequency correlation interval in a single-beam decameter radio link. It is shown that an increase in the decameter communication range leads to an expansion of the fading frequency correlation intervals, and an increase in the level of ionospheric diffuseness leads to an increase in the root-meansquare deviation of fluctuations of the wave phase front at the ionospheric outlet, which affects the decrease in the maximum value of the fading frequency correlation interval, which observed at a lower optimal value of the operating frequency in a single-beam decameter radio link. The results obtained will allow us to assess the noise immunity of signal reception at different values of frequency correlation intervals, including the occurrence of frequency-selective fading.