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Background. Telecommunication systems with a broadband signal have undoubted advantages: increased noise immunity with narrowband and wideband interference, confidentiality of information transmission, as well as improved electromagnetic compatibility with neighboring radio-electronic devices. A broadband signal is usually formed by direct spread spectrum using well-known classical pseudo-random sequences (PRS): m-sequences, Kasami, Gold, Walsh sequences, which can be decoded and received at the receiver. Objective. The aim of the paper is creating PRS on the basis of chaos, which the subscriber is practically unable to decode, and thus ensure increased confidentiality of information transmission. Methods. Using the mathematical model of chaotic logistic mapping, which, as shown by preliminary studies, provides the best results, as well as referring to the bifurcation diagram of Feigenbaum, the parameters of 3-secret keys are defined and the PRS of the selected length is created. Based on the application of the graphical user interface developed in the MATLAB system, a correlation analysis of the resulting PRS is performed and the PRS is determined with the minimum side lobes of the autocorrelation function. Results. By empirical decision of 3 secret keys of the dynamic parameter of the Feigenbaum diagram, the initial value of the sequence and the number of the initial pulse of the PRS, as well as the study of the autocorrelation function, we obtained a PRS with a side lobe level of the autocorrelation function acceptable for practical use of no more than 0.25. Conclusions. The use of well-known pseudo-random sequence: Walsh's, Kasami's, Gold's, creating a system with a noise-like signal doesn't ensure complete confidentiality of information transmission, since they can be decoded. The most acceptable by the criterion of the side lobe minimum of the autocorrelation function-no worse than 0.25-is the use of chaos based on the Feigenbaum logistic map. When creating pseudo-random sequences based on chaos, the best results are obtained by choosing the maximum value of the dynamic parameter of the Feigenbaum diagram at the level of the boundary value equal to 4, with an accuracy of 0.05.

In telecommunications, a particular place belongs to systems with a wideband noise-free signal, the undisputed advantage of which is increased by both narrowband and wideband interference, confidentiality of information transmission, as well as electromagnetic compatibility with adjacent electronic devices. A wideband noise-free signal is formed using a number of known modulated sequences - m-, Kasam-, Gold sequences, typically by direct spreading.Systems using known pseudo-random sequences cannot be considered protected from unauthorized access.An effective way to increase the confidentiality of signal transmission in a noise-free TSC is to use a chaotic signal-based PVP.Pseudorandom sequence generators are based on one-dimensional chaotic reflections such as logistics, quadratic, and cubic. Researches have shown the undeniable advantage of logistical reflection. The construction of hidden communication systems using the deterministic chaos phenomenon is progressive issue nowadays. Several main stages should be carried out for achieving the goal. These are providing of the stability degree of synchronization between the drive and response generators of the transmitter and receiver respectively, investigation of chaotic oscillation to estimate the noise similarity and hardware design of communication system. It is known that the stable synchronization mode is needed for the quality level of data recovery. Therefore the basic conditions were computed for unidirectional coupled chaotic generators for the purpose of providing of generalized synchronization. To construct the communication system with high hiding degree first of all it is necessary to select the chaotic carrier signal the spectral and statistical characteristics of which were similar to noise. Using the obtained results the hardware prototype of hidden communication system was constructed

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