One of the directions to improve the efficiency of modern telecommunication systems is the transition to the use of multidimensional signals for continuous channels of information transmission. As a result of studies carried out in recent years, it has been established that it is possible to ensure high quality of information transmission in continuous channels by combining demodulation and decoding operations into a single procedure that involves the construction of a code construct for a multidimensional signal. This paper considers issues related to estimating the possibility to improve the efficiency of continuous information transmission channel by changing the signal distance of the code structure. It has been established that the code structures of such types as a hierarchical code construct of signals, a hierarchical code construct of signals with Euclidean metric, a reversible code construct of signals, a reversible code construct of signals with Euclidean metric have the potential, when used, to increase the speed of information transmission along a continuous channel. With a signal distance reduced by 10 percent or larger, it could increase by two times or faster. The estimation of the effect of reducing a signal distance on the efficiency of certain types of code structures was carried out. It has been established that the hierarchical reversible code construct, compared to the hierarchical code construct, provides a win of up to two or more times in the speed of information transmission with a halved signal distance. Implementing the modulation procedure has no fundamental difficulties, on the condition that for each code of the code construct the encoding procedure is known when using binary codes. The results reported here make it possible to build an acceptably complex demodulation procedure according to the specified types of code structures

The structure, role and place of atmospheric-optical communication lines in modern information transmission systems and increasing the efficiency of their functioning are considered. The factors are analyzed, and especially such an environmental factor is taken into account, which directly affects the technical characteristics of the element base of atmospheric-optical communication lines, such as radioactive radiation. The source of such radiation can be a nuclear power plant accident, as a result of which a large amount of radioactive substances spreads into the surrounding space outside the nuclear power plant. The analysis of the radiation resistance of the element base of atmospheric-optical communication lines is carried out, which shows that the most vulnerable structural elements are infrared receivers. The technical condition of the receivers of atmospheric-optical communication lines under the influence of radioactive radiation will determine the general technical condition of the information system and affect the possibilities for their application. Radioactive radiation, which is also present in the space environment, is one of the factors in the manifestation of external influences and on the technical condition of aerospace technology. The radiation that occurs in the structures of integrated circuits when bombarded with high-energy particles leads to the generation of photocurrents that can change the operating characteristics of integrated circuits, in turn leads to failures in the transmission of information and to complete failure in emergency situations. The directions of improving the methods of accounting for the influence of atmospheric-optical communication lines on receivers are proposed.

Object of research: Free-space optical communication (FSO). Investigated problem: Significant advantages of free-space optical communication in comparison with the existing networks of useful data transmission justify their use in various complex environmental conditions, which require the organization of fast and reliable digital communication when it is impossible or limitation to use wired or radio lines. Main scientific results: One of the factors that can considerably affect the FSO efficiency is radioactive radiation produced by various sources and phenomena of ionizing effects. In the research the issues of the assessment of the vulnerability of the FSO receivers of input signal from the effects of gamma radiation are directly considered. The analysis of the design of the receiving path of the input signal of FSO is conducted and the list and the partial attenuation coefficients of radioactive radiation by the FSO components that separate the receiver of input signal from the external environment are determined. The area of practical use of research results: The methods has been developed and with its help the assessment of the vulnerability of the FSO receivers of input signal from the effects of gamma radiation, as the effects of the destruction of the radiation-hazardous object has been conducted. Innovative technological product: The nature of the influence of gamma radiation as the effects of the destruction of the radiation-hazardous object on the FSO receiver of input signal is determined. Scope of application of an innovative technological product: The results allow to develop a set of measures aimed at reducing the effects of gamma radiation, as the effects of the destruction of the radiation-hazardous object, on the FSO efficiency.