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  • Ескіз
    Документ
    Analysis of the known methods of channels communication control with the interference and selective fading
    (Національний технічний університет "Харківський політехнічний інститут", 2019) Zhyvotovskyi, Ruslan; Momit, Alexander; Onbinskyi, Yaroslav; Lyashenko, Anna
    Designing adaptive radio systems, depending on their purpose, solves the problem of optimizing one of the performance indicators with restrictions on others. In turn, the development and implementation of adaptive information sharing techniques require the establishment of effective procedures for monitoring and predicting the status of communication channels and the quality of information transmission. Given the rapid development of electronic warfare facilities, the expansion of the list of interferences that can be created by these complexes, it is great relevance for further scientific research on the creation of new methods of monitoring the status of the communication channel. In this research, the authors analyzed the characteristics of the main methods for assessing the status of communication channels. In the course of the analysis, the authors used general scientific methods of analysis and synthesis, the basic provisions of communication theory, data transfer theory, space-time coding theory, noise immunity theory, signal-code theory, etc. The authors of the article analysis of the known methods of estimating the state of the channel of multi-antenna communication systems showed that the known scientific articles do not contain the following: parallel estimation of the status of the channel by several indicators; obtaining a generalized channel status assessment; continuous evaluation of several characteristics in real-time; at the same time evaluate both the linesdown and the lines up; the combination of the impulse response of the channel state, the frequency response of the channel status, and the bit error probability is not used for the estimation. It is established that at present there is no universal methodof monitoring the status of channels of multi-antenna radio communication systems, which would give an accurate, fast estimate of the status of the channel in real-time, which would allow effective adaptation in a channel with non-stationary parameters.
  • Ескіз
    Документ
    Analysis of the properties of non-orthogonal methods of signal processing in МІМО systems
    (Національний технічний університет "Харківський політехнічний інститут", 2018) Zhyvotovskyi, R.; Momit, O.
    Conflicts of the last decades (the Chechen war (Russian Federation), armed confrontation in the countries of the Middle East and North Africa, anti-terrorist operation in the territory of Donetsk and Lugansk regions (Operation of the United Nations)) go beyond the existing (traditional) forms and methods of warfare, conducted on the background of information and psychological operations and the active using of electronic emitters. One of the directions of increasing the noise immunity of radio communication devices is using of multi-antenna radio communication systems. They are complex technical systems. There are many approaches to increasing the impedance of multi-antenna systems, but the authors of this article limited themselves to considering only the methods of signal processing, namely, non-orthogonal spatial-temporal codes. During the research, the authors used the basic provisions of the theory of communication, the theory of antennas, the theory of noise protection and signal-code structures. In the course of the research, it was found that non-orthogonal methods of spatial-temporal signal processing have more spectral efficiency than orthogonal ones, with an equal number of transmitting antennas, but they lose in energy efficiency the orthogonal methods of space-time signal processing. Using of non-orthogonal codes leads to the increasing the number of computational operations in the receiver of the radio communication device. All this results in further research on the development of the spatial-temporal signal coding method in multi-antenna radio-communication systems with high energy and spectral efficiency, and it is necessary, that the proposed method has an acceptable computational complexity.
  • Ескіз
    Документ
    Analysis of signal processing methods in МІМО systems
    (Національний технічний університет "Харківський політехнічний інститут", 2018) Zhyvotovskyi, R. M.; Momit, O. S.
    Conflicts of the last decades (the Chechen war (Russian Federation), armed confrontation in the countries of the Middle East and North Africa, anti-terrorist operation in the territory of Donetsk and Lugansk regions (Operation of the United Nations)) go beyond the existing (traditional) forms and methods of warfare, conducted on the background of information and psychological operations and the active using of electronic emitters. Therefore, provision of sustainable communication is one of the priority directions of scientific research. One of the directions of increasing the noise immunity of radio communication devices is using of the multi-antenna radio communication systems. However, they are complex technical systems. There are many approaches to increasethe impedance of multi-antenna systems, but the authors of this article limited themselves to considering only the methods of signal processing, namely orthogonal spatial-temporal codes. During the study, the authors used the basic provisions of the theory of communication, the theory of antennas, the theory of noise protection and signal-code structures. In the course of the analysis, the authors found, that the computational complexity of the orthogonal codes used in MIMO systems is directly proportional to the number of transmitting antennas in the system, which leads to a linear increase in the number of computational operations in the processing of signals was using mentioned spatio-temporal codes. However, this type of spatial-temporal codes has high energy efficiency in MIMO systems with a small number of antennas. The authors propose to develop a method of space-time coding of signals in multi-antenna radio systems with high energy and spectral efficiency, when the proposed method had an acceptable computational complexity.
  • Ескіз
    Документ
    Method of signal processing in МІМО systems of unmanned aviation complexes
    (НТУ "ХПІ", 2018) Zhyvotovskyi, Ruslan; Petruk, Sergii
    Noise immunity of receiving signals in the MIMO (Multiple Input Multiple-Output) system essentially depends on the choice of the signal processing method on the receiving side. Existing methods of signal processing, in the MIMO system, that provide a given quality of information transmission, have high computational complexity, so there is a necessity to improve these methods. The purpose of this article is to increase the impedance of channels of control and data transmission of unmanned aerial systems, which was achieved by developing new method of signal processing in multi-antenna systems of unmanned aerial systems. The article developed an improved method of signal processing in MIMO systems of unmanned aerial systems, the essence of which is the ability to work with a known and unknown correlation matrix, the division of received signals into groups and the evaluation of each group, taking into account the evaluation error. During the research, the theory of communication, signal theory, the theory of antennas and the theory of noise-proof coding were used. The difference between an improved method is, that the method allows you to work with an unknown correlation matrix. While processing a signal in a demodulator, each iteration takes into account not only the estimate obtained in the previous step, but also the degree of accuracy of the character estimation. The proposed improved method has characteristics, that are close to the characteristics of demodulator, optimal for the criterion of maximum likelihood, but much less computational complexity. The method allows you to reduce computing costs by 20 times,compared with the maximum likelihood algorithm. The practical implementation of this method will allow the creation of software for communication equipment of unmanned aeronautical complexes, which operate in difficult conditions of the radio electronic environment.