Перегляд за автором "Zheng Yu"

Зараз показано 1 - 3 з 3
  • Зображення мініатюри
    Публікація
    Consideration of Antenna Pattern by Elevation in Recommendation ITU-R P. 2001
    (IEEE, 2020) Chernov, A.; Kovshar, V.; Kaliuzhnyi, M.; Zheng Yu
    The question of the practical application of the comprehensive universal Recommendation ITU-R P.2001 in calculating the electromagnetic compatibility of electronic systems is considered. In this Recommendation antenna patterns are assumed isotropic in elevation plane. It is shown that to increase an accuracy of calculations by this technique, it is necessary to take into account the difference between the terminal antennas pattern and isotropic antennas. A detailed analysis of the propagation of radio waves sub-model for reflection from the sporadic layer E. The significant influence of the distance between the terminals and the types of their antennas on the calculation results for this sub-model. The quantitative corrections for typical short-wave and ultra-short wave antennas are determined. The directions of further research were selected to increase the accuracy of calculations of the propagation of radio waves when using the Recommendation ITU-R P.2001.
  • Зображення мініатюри
    Публікація
    Optimization and mathematical modeling of communication networks
    (PC «Technology Center», 2019) Bezruk, V. M.; Семенець, В. В.; Chebotarova, D. V.; Kaliuzhniy, N. M.; Guo Qiang; Zheng Yu
    The main attention is paid to optimization issues, as well as mathematical modeling of systems that are important for the initial stages of the design of communication networks. Examples of solving scalar and vector optimization problems are given taking into account mathematical models of various types of communication networks. Information is given about standard sofware packages that can be used for optimization and computer simulation of communication networks.
  • Зображення мініатюри
    Публікація
    Selection and recognition of the specified radio emissions based on the autoregression signal model
    (Radio Electronics, Computer Science, Control, 2020) Bezruk, V. M.; Kaliuznyi, N. М.; Nikolaev, I. М.; Qiang Guo; Zheng Yu
    Context. A solution to the relevance problem of selecting and recognizing specified radio emissions in the presence of unknown radio emissions in automated radio monitoring is considered. It is proposed to solve the problem in an unconventional method for the recognition of statistically specified random signals in the presence of a class of unknown signals. Objective. The goal of the work is іnvestigation of the possibility of using random signal recognition methods in conditions of increased a priori uncertainty to solve the problem. The features of the signal recognition method are discussed, as well as the results of a study of the recognition quality indicators of given radio emissions, which are obtained by statistical modeling on samples of the corresponding signals. Method. The recognition method is based on the description of signals by a probabilistic model in the form of Gaussian autoregressive processes. It is proposed to use the new decision rule for the selection and recognition of statistically specified signals in the presence of unknown signals class. The proposed method of signal selection and recognition can be implemented in a recognition system that operates in training and recognition modes. In the training mode, unknown parameters of the decision rule are evaluated by classified samples of the given signals. Results. Research conducted by statistical tests on samples of the corresponding signals characteristic of automated radio monitoring of radio communications equipment. Practical results of studies of the problem of selection and recognition of specified radio emissions are presented. Values of indicators of quality of radio emissions recognition acceptable for the practice of radio monitoring are obtained. The dependences of quality indicators on some conditions and recognition parameters are investigated. Conclusions. Undertaken studies showed possibility of decision of problem by application of an unconventional method of selection and recognition of specified random signals. The practical significance lies in obtaining recommendations on the construction of systems for the recognition of radio emissions for specialists in the design of automated radio monitoring complexes. Such signal recognition systems are implemented by computer technology and is adaptive. The structure and parameters of the systems are set according to the samples of signals that are obtained for the corresponding given radio emissions.