Investigation of multipath compensation efficiency in communication channels using filters with inverse impulse response

Objectives. A key challenge when transmitting data in modern communication systems is the multipath propagation of signals caused by reflections from various obstacles. Various methods have been developed to address this issue including: directional antennas; diversity reception; adaptive filtering; and the choice of effective modulation methods. One promising approach is the use of filters with impulse response (IR) inverse to IR channel. This allows for compensating delayed signals. The effectiveness of such filters depends on the accuracy of their parameter settings. The paper aims to develop guidelines for effectively using filters with inverse IR to compensate for multipath. Additionally, it aims to evaluate the impact of various channel parameters, such as time delays and reflected signal intensities, on the bit error rate (BER) and to determine the energy gain.

Methods. The methods of statistical radio engineering, the theory of optimal signal reception and mathematical modeling were used.

Results. The results of a study on the effectiveness of multipath compensation in communication channels when using filters with inverse IR to that of the channel at the receiving side are presented. A multipath communication channel model was developed in the Simulink software environment, consisting of six beams with different time delays and intensities. Discrete information reception was simulated using different modulation methods: 16-QAM (quadrature amplitude modulation), 8-PSK (phase-shift keying), and 8-FSK (frequency-shift keying). The BER value was estimated depending on the signal-to-noise ratio and multipath channel parameters, including time delays and reflected beam intensities. It was shown that the use of filters with inverse IR can significantly reduce BER and improve communication quality. The change in the BER value is estimated for deviations of filter parameters from the ideal ones.

Conclusions. The results demonstrate that the use of compensating filters is effective in combating multipath distortion, especially under strong interference conditions. The data obtained can be used for the design and optimization of modern communication systems operating in complex signal propagation conditions.

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