The article describes an algorithm for calculating polarization losses, which are one of the energy characteristics of a HF communication channel when planning radio link of various paths and arbitrary relative positions of the receiving and transmitting points. Using the proposed method, numerical modeling of this type of loss for a given set of input parameters of communication link in the decameter range has been carried out. Based on the calculation results, conclusions were drawn regarding the behavior of polarization losses under various conditions.
The paper presents a discrete-event model of non-maintained railway telecommunication equipment operation. The model developed in the AnyLogic environment allows to estimate the availability factor and specific quality indicator of such systems, as well as to predict time spent in various states. The presented model can be used both at the design and operation stage for the compliance assessment of telecommunication equipment parameters with the reliability requirements.
The features of the four-component refractive dielectric model of moist soils are considered. Typical values of the parameters of the Debye model of bound water obtained by processing experimental data using this model are given. The reasons why the parameters of the Debye model of free soil water in this model differ from the true values of these parameters are explained. It is shown that the excess of the static permeability and specific conductivity values relative to the true values is caused by the Maxwell – Wagner relaxation process with a relaxation time of sev-eral nanoseconds.
This paper presents the research of methods for decrease of the capacitance ratio in the STW-resonators without significant degradation of the quality factor by use of the external inductors and topology change: IDT division on parts and their series connection. The calculated and experimental data are presented for 416 MHz and 766 MHz STW-resonators with quality factors Q = 7000–7978. The capacitance ratio has been reduced from 1200 to 301.
The article proposes an algorithm for time-frequency synchronization of a high-speed modem operating under conditions of a highly dispersing channel, supplemented by an autocorrelation algorithm. It is shown that under the conditions of ray energy redistribu-tion, the proposed algorithm makes it possible to achieve satisfactory synchronization.
