Design of a dispersion distortion compensation filter: impact of a rectangular window on the Gibbs phenomenon in the frequency sampling method

To increase the data transfer rate, it is necessary to expand the bandwidth of the transmitted signal. However, the dispersion properties of the ionosphere lead to significant distortions on the receiving side. There are various models for describing such effects, among which the polynomial model is the most preferred and easy to use. When synthesizing a compensator filter based on a polynomial model, when truncating the spectrum, it is necessary to take into account the influence of the Gibbs effect, which manifests itself in the form of sharp oscillations at the boundaries of the signal bandwidth. The RMS deviation of the amplitude-frequency response and phase-frequency response of the compensator filter are studied before and after truncation by a rectangular window at different values of the steepness of the dispersion characteristic.