Impact Assessment of the Chirp Signal Frequency Change Rate on the Energy Secrecy and Noise Immunity

Abstract

The article deals with the issues of noise immunity and energy secrecy of chirp signals. The purpose of the article is to study the rate of chirp signal frequency change and its influence on signal parameters, such as the envelope and spectrum of the signal, the degree of its energy secrecy and noise immunity. A study was made of the chirp signal frequency change rate influence on the amplitude spectrum of the transmitted signal. The study showed that an increase in the chirp signal frequency change rate leads to an increase in the slope control of the sawtooth voltage. In this case, the width of the amplitude spectrum changes in direct proportion to the change in the frequency band. Based on the results, the assumption was made about the positive effect of increasing the slope of the control signal on noise immunity and energy secrecy. The effect of the chirp signal frequency change rate on the degree of energy secrecy is studied by means of the author's method to estimate the energy of the transmitted symbol. The simulation results showed that the rate of change in the frequency of the chirp signal does not lead to a change in energy and does not affect the degree of energy secrecy. A study was made of the chirp signal frequency change rate influence on the noise immunity of the transmitted signal. It was proposed to investigate a real high-frequency chirp signal using the weighting method on a set of matched filters. The method made it possible to investigate the noise immunity of chirp signals with different parameters and compare the obtained data with the noise immunity of the GMSK signal of the Gonets-M satellite communication system. As a result, some regularities were found that allow us to evaluate the effect of the rate of change in the frequency of the chirp signal on its noise immunity. Comparison of GMSK and chirp signals made it possible to verify the effect of introducing chirp signals into satellite communication systems. As a result of the study, conclusions were drawn about the influence of the choice of chirp signal frequency change rate on noise immunity and energy secrecy.