Özet:

We have examined technologies for building 5 G mobile networks, which should provide for the creation of ultradense networks in order to render high-quality services. A formalized statement of the problem on synthesis of the optimal signal based on conditions for relative invariance to an additive interference has been prepared. A method for the optimization of signal parameters based on a mean square criterion has been developed. We have proposed to solve the optimization problem by applying the nonlinear programming methods. It has been shown that solving this problem makes it possible to find a signal with the predefined parameters, invariant to deterministic interferences. We have developed a method for the optimization of signal parameters based on a uniform criterion. The method is based on determining a totality of signal decomposition coefficients, at which a maximum of the module of an output signal form a demodulator, taken for all values of a random parameter, is minimal. It has been proposed to solve the problem by employing the linear programming methods. Application of this method makes it possible to improve noise immunity in a data transfer system and increase the rate of information transmission along a communication channel. Synthesis of the optimal signal with respect to the additive interference has been performed. A given signal renders the maximum possible noise immunity to the system. We have considered a discrete difference transform that possesses a universal property of invariance relative to a wide class of interference.It has been shown that the achievement of an absolute or a relative invariance and the expediency of applying one of the specified methods depend on the characteristics of an interference, the degree of their a priori certainty, as well as the feasibility to form a reverse communication channel. Simulation results have shown that the methods for the formation of an invariant signal, proposed in this paper, could improve a system noise immunity in the communication channel by 5‒7 dB. Introduction of the devised methods would make it possible to increase the rate of transmitted information by 30 %, provided the assigned reliability of data transfer is ensured. Enabling the invariance of an information transfer system would make it possible to build the ultradense fifth-generation networks Author Biographies Volodymyr Tolubko, State University of Telecommunications Solomyanska str., 7, Kyiv, Ukraine, 03110 Doctor of Technical Sciences, Professor Department of Telecommunication Systems and Networks

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