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Simultaneous transmission of photonic services in fibre optics
Látal, Michal ; Horváth, Tomáš (referee) ; Münster, Petr (advisor)
Diploma thesis focuses on simultaneous transmission of selected photonic services by one single-mode optical fiber. The thesis deals with the problem of common transmission of multiple photonic services by one optical fiber using the wavelength division multiplex technology. Furthermore, the origin and influence of nonlinear phenomena accompanying the simultaneous transmission of photonic services are described. Except common data transmission with a bitrate of 10 Gbit/s, a common high-speed data signal transmission with a bitrate of 200 Gbit/s, accurate time transmission and high-power sensor signal are considered. During the aimultaneous transmission of selected photonic services, the measurement of the transmission parameters was performed for various variants of the simultaneous transmission arrangement. In particular, the influence of nonlinear phenomena and possible mutual interference of individual transmission channels at 50 and 100 GHz between signals was analyzed.
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Wireless transmission interference modeling (AWGN, Rayleigh, Rice fading channels)
Hloušek, Tomáš ; Gleissner, Filip (referee) ; Mikulka, Jan (advisor)
This thesis describes and models wirelesss transmission intereferences in real communication channels. A signal received on a fading channel is subjected to a multiplicative distortion and to the usual additive noise. Real channel adds to the signal noise and fadings. Gaussian noise is a result of channel awgn. Fadings is implicated by multipath propagation of signal in Rayleigh and Rician channels. Main goal of this project is to program BERsolve, which is created in tool GUIDE in Matlab. User program BERsolve makes it possible to analyse bit error rate and symbol error rate for some types of channel models, which are defined by standard COST207. BERsolve offers some other functions i.e. display time behaviour, constellation diagram and spectrum. This program provides us with an overview representation of problem by multipath interferences in communication channels.
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Modulation technique design for radio channels with interference
Bělohlávek, Jiří ; Kubánková, Anna (referee) ; Pust, Radim (advisor)
This thesis concisely describes essential type of modulation technique for transmission of binary signal. In introductory part there are summarized advantages and disadvantages for each described modulation technique. There are described proceeding of modulation and demodulation too. Next part is specialized mainly to determination of incorrect receiving probability. For each modulation technique are calculated theoretical values of bit error rate and compiled graph. In practical part there are described possibilities of Matlab platform for measurement of bit error rate. In implement Simulink there is built model of communication channel with additional AWGN channel. Graphs are constructed from simulation data by the help of model’s control script. On selected modulation technique are inspected various elements which are reacted with graph. In finale part there are compared theoretical and measured values and summarized analysis.
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Analysis of digital modulation robustness at various types of interference
Uher, Tomáš ; Šilhavý, Pavel (referee) ; Kubánková, Anna (advisor)
This bachelor thesis concisely describes essential type of modulation technique for transmission of binary signal. In first part there are summarized advantages and disadvantages for each described modulation technique. There are described proceeding of modulation and demodulation too. Selected digital modulations are tested for Gaussian, Rice and Rayleigh transmission channels. In final part there are compared theoretical and measured values and summarized analysis.
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GSM-EDGE and UMTS Systems Coexistence
Gleissner, Filip ; Hanus, Stanislav (advisor)
The dissertation thesis deals with the investigation of the coexistence of GSM–EDGE and UMTS systems with focus on the physical layer of the systems. The aim is to provide a set of recommendations for practical cooperation while the systems operate in both the separated and the common radio bands. A detailed description of signal processing of both the systems on the physical layer is presented. On the basis of this description, models of both systems were created and implemented in the MATLAB environment. The simulations are focused on the physical layer quality parameters, especially the bit error ratio evaluation for various ratios of useful signal power to noise power during the transmission over the radio channel. Simulation is also used to examine the quality of received useful signal while it is interfered by signals from the same and adjacent channels. The purpose is to determine the isolation between these adjacent channels, when the bit error ratio of the useful signal does not exceed a certain reference value. The simulation results are subsequently subjected to comparison with the results of the experimental measurements in laboratory conditions. Before the measurements are carried out, a study of possible interference types is performed. Consequently, the crucial parameters of the measuring equipment used are verified. From the results of simulations and measurements, the proposal of a minimum and recommended carrier separation between both the systems is presented in order to efficiently utilize the assigned frequency spectrum. Furthermore, for the cooperation in both the separated and the common radio bands, the necessary precautions are given for reaching the required isolation and thereby inter-system interference minimization.
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NEW CHANNEL CODING METHODS FOR SATELLITE COMMUNICATION
Rumánek, Jaroslav ; Levický, Dušan (referee) ; Žalud, Václav (referee) ; Šebesta, Jiří (advisor)
This dissertation thesis deals with new progressive channel coding methods for data transmission using satellite transponder. The design of the system for SMS transmission, in which novel turbo coding methods are applied, is discussed too. An achievement of the lowest output power and the smallest user aperture is the principal aim of the new method applications. Design of system that would be able to the error free SMS transmission by very low signal to noise ratio is analyzed in this dissertation thesis. The work is focused on energy budget, modification and implementation of new turbo code types and using unique properties, development of new bit error rate estimation methods and methods for determination of final SMS form. The main contribution is the new type of turbo code development that have optimal properties for this usage, development of new bit error rate estimation method and development of method that is able to determine final form of SMS on the basis SMS frame structure and turbo decoding theory when the bit error rate is not zero.
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Demonstration of optimal receivers for the AWGN channel
Musil, Petr ; Šilhavý, Pavel (referee) ; Číž, Radim (advisor)
This thesis deals with the demonstration of bit error rate reduction techniques. In the theory section, different techniques of bit error rate reduction are presented, followed by the introduction of the communication channel and the communication system parameters. Each technique is simulated in Matlab Simulink environment using the additive white Gaussian noise channel model. The simulations are captured in waveform oscillograms of all the signal processing stages. The practical section of this thesis offers a functional laboratory solution demonstrating different ways of transmission: a direct-path signal, a path with a cross-correlation receiver and a path using matched filtering. The individual circuits are described in detail, including waveform oscillograms of the signal processing blocks for illustration. Furthermore, the practical section presents printed circuit boards designs, comprehensive documentation for production, measurement results and a sample laboratory protocol.
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Simultaneous transmission of photonic services in fibre optics
Látal, Michal ; Horváth, Tomáš (referee) ; Münster, Petr (advisor)
Diploma thesis focuses on simultaneous transmission of selected photonic services by one single-mode optical fiber. The thesis deals with the problem of common transmission of multiple photonic services by one optical fiber using the wavelength division multiplex technology. Furthermore, the origin and influence of nonlinear phenomena accompanying the simultaneous transmission of photonic services are described. Except common data transmission with a bitrate of 10 Gbit/s, a common high-speed data signal transmission with a bitrate of 200 Gbit/s, accurate time transmission and high-power sensor signal are considered. During the aimultaneous transmission of selected photonic services, the measurement of the transmission parameters was performed for various variants of the simultaneous transmission arrangement. In particular, the influence of nonlinear phenomena and possible mutual interference of individual transmission channels at 50 and 100 GHz between signals was analyzed.
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