Study of noise immunity of signals subject to narrow-band non-Gaussian interference

This article presents a study of the effect of non-Gaussian distribution of the interference and noise mixture on the noise immunity of signal reception with spread spectrum and binary phase modulation. The interference models used correspond to interference observed on the air in the decameter wavelength range - a phase-shift keyed signal and a signal with linear frequency modulation. The results of simulation modeling are presented, showing that the deviation of the distribution from the Gaussian affects the noise immunity of reception to varying degrees depending on the structure of the interference itself. Small deviations from the Gaussian nature of the interference and noise mixture do not lead to significant losses in noise immunity of signal reception with BPSK. Non-Gaussian distribution of the interference and noise mixture does not always lead to significant losses in noise immunity. For example, with QPSK interference, the noise immunity is the same as with a Gaussian type of interference, while interference in the form of a chirp signal causes a significant increase in the error probability. Consequently, the reduction of the level of noise immunity of reception depends not only on the distribution of the interference, but also on its structure. A check was made for compliance with the Gaussian distribution of a natural recording of a mixture of interference noise from real air. The study of the air recordings using four statistical criteria established an insignificant difference in the distribution of the group interference signal from the Gaussian law. The results of the sonogram study confirmed the need to use a mechanism for adapting the signal reception algorithm to the shape of the spectral power density of the group interference due to its dynamic change due to the intermittent nature of some narrowband signals.