TIMED SIGNAL CONSTRUCTIONS AS A TOOL FOR CODE CHANNEL MULTIPLEXING

Abstract

The feasibility of transmitting information from two or more sources in one code word is evaluated, an algorithm is proposed for increasing the information capacity of a Nyquist’s element in a binary channel without increasing the length of a code word. Reuse of communication channels is that it is carried out an independent transfer of information from several sources. At the same time, for each pair of correspondents (source and receiver) an individual channel is provided, because of which the system as a whole becomes multi-channel. In communication systems, multichannel systems have become common with channel separation based on the physical characteristics of the signals used. On this basis, there are systems with an amplitude compaction method (ASC), frequency compaction method (FSC), phase compaction method (PSC), and time channel compaction method (TSC). At the same time, often used signal parameter (amplitude, frequency or phase) is applied in the relative modulation mode. It should be noted that the above methods of modulation and channel separation do not efficiently use the frequency band and transmission time . In this article, a two-fold (or Z-fold) multiplexing of the implementation interval of code constructions is considered: each codeword contains information about two (or Z) characters of the transmitted text. The paper compares the time spent on the synthesis of enlarged signal codewords that ensure the transmission of information on Z symbols in positional coding and the use of enlarged code constructions generated on the basis of timer signals. Estimates confirm that the time-based signals reduce the time costs by more than two times as compared with positional coding. Such efficiency of timer coding is provided by different values of the minimum energy distance between code words in positional and timer coding: in the first case, this distance is determined by the energy of the Nyquist’s element, and in the second, by the energy of the base element ∆, which is 5…7 times smaller, than the Nyquist’s element and determined by the channel bandwidth.