Synthesis of a measuring composite signal for assessing the security of speech signals during discrete-quantized transformation

Abstract

The purpose of the work is to systematically analyze and generalize a high-precision measuring signal for assessing the security in leakage channels in high-level noise by discrete-quantized representation of speech signals using the principles of amplitude-pulse modulation. It has been established that time sampling and level quantization of high-speed high-quality speech signals for digitalization are the main sources of information leakage. It is shown that to determine the degree of information security for high-quality high-speed transmission in broadband information transmission channels, it is necessary to use a complex measuring (test) composite signal. Requirements for the measuring signal are determined by the features of the discretequantized representation of speech signals. It is proposed to use a periodic pulse sequence of a triangular shape as a measuring signal. The triangular measurement signal has an advantage over the harmonic signal in the quantization noise extraction process, since allows you to achieve higher accuracy when processing it. To assess the security of the channel due to pulse-amplitude modulation, a harmonic signal is used, formed from a periodic pulse sequence of a triangular shape by the Fourier transform method. The use of the proposed measuring composite signal makes it possible to establish its numerical dependence with the numerical value of the signal taken as normalized and compare it to make a decision about the security of the speech signal. The materials presented in the article are original and can be used to assess the security of the channels of leakage of speech signals converted into digital form. In addition, the results obtained make it possible to carry out further studies of the security of speech signals during their reverse conversion from digital form to the original signal.