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Transmission analysis and measurements in digital television DVB-S/S2
Kaller, Ondřej ; Ulovec,, Karel (referee) ; Kratochvíl, Tomáš (advisor)
This master’s theses consists of theoretical introduction which includes basic search of referenced literature about digital television systems and picture quality classification. The results of signal character measurement of selected TV channels from satellites ASTRA 1E (DVB-S) and ASTRA 1L (DVB-S2) are provided. The energy budget calculation of downlink and results of 24-hour TS error rate measurement is included as well. The video quality by DVQL metric for each particular program of CS link stream was measured during full 24 hours.
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Modelling of PLC system to ensure the reliability of communication
Procházka, Vít ; Mišurec, Jiří (referee) ; Mlýnek, Petr (advisor)
The master´s thesis is focussed on principles and characteristics of Powerline Communications (PLC), practical usage possibilities and advantages and disadvantage of it. There are described mudulations and a channel encoding which are in PLC used. The main part of the thesis deals with a design of a channel as transfer function through the use of two methods, an echo model and the ABCD matrix. After finishing of the design of transfer function the model of communication was created in the Matlab-Simulink program. There were used the narrowband modulations in the model and analyzed the bit error rate of the tranfer data. In the end all results were treated graphically and evaluated.
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Navigation systems
Jirkovská, Šárka ; Stejskal, Vojtěch (referee) ; Pust, Radim (advisor)
This bachelor´s thesis is focused on the navigation systems GPS, Galileo and their development. The work describes the functions and parameters of mentioned navigation systems including individual modulation techniques, used frequencies and signal securing by encoding. Segments of navigation systems GPS and Galileo, which divide into control and space parts, are mentioned next. The principle of signals generation by GPS system satellites, where the navigation message is the basis of user´s data transfer, is introduced. The principle of generation of the navigation message is described as well as its structure and characteristics of used CA-code and P-code. Next part of the work presents the components of the Galileo navigation system satellites and conspectus of planned services of this system. The summary of used receivers’ characteristics and summary of selected producers of digital geographical data for navigation devices follow next. The last part mentions the simulation of signal generation of GPS satellite. The simulation includes encoding and decoding of navigation message. This simulation is created in Matlab version 7.4 environment.
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TV Remote Controller
Bordács, Balázs ; Hála, Ondřej (referee) ; Hermany, Jiří (advisor)
This master’s thesis deals with parameters of the TV Remote Controller. Aim of this work is studying standards of remote controling of TV receiver by the way of infra-red light. For succesful solving of this project is important to learn about the theory of IrDA. In the second part ot this thesis is designed measurement unit for measuring the parameters of the remote control. The measurement unit includes an integrated IR receiver and photodiode for receive IR signals from remote control. The description of measurement unit blocks and principles of measuring parameters are also placed there. The final part is devoted to processing the measurement results of measuring levels and time waveforms of signal in the receiver module, directional characteristics of remote control and receiver. For measuremented unit is created laboratory task including the role specification and protocol.
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Classification of digital modulation type
Balada, Radek ; Kováč,, Michal (referee) ; Povalač, Karel (advisor)
The aim of master’s thesis is a classification of digital modulation type. The interest in modulation classification has been growing for last years. It has several possible roles in both civilian and military applications such as spectrum sensing, signal confirmation, interference identification, monitoring and so on. Modulation classification is an intermediate step between signal detection and successful demodulation. Therefore the known methods are based on different statistics obtained from received signals. These statistics can be derived from continuous time signals and they hold for sampled signals.
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Design and implementation of LAN home network using PLC technology
Pataj, Jiří ; Lattenberg, Ivo (referee) ; Mišurec, Jiří (advisor)
Master’s thesis deals with possibilities of data communication on low voltage power lines, so-called PLC. This technology allows data transfer on power lines. According frequency band the PLC can be subdivide into narrowband or broadband class. Given are theoretical knowledge’s of data communication on power lines and describes technical solutions. Consequently is suggestion of LAN, which is accessible for commercial usage made by DS2 and his suitable for home use. The main acquisition is implementing and measuring this experimentally created LAN in family house. The results are real bitrates depending on distance and quality of specific connection.
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FM Coincidence Detector - Laboratory Equipment
Mlčoch, Jiří ; Urbanec, Tomáš (referee) ; Baran, Ondřej (advisor)
This work is aimed at an analysis of frequency demodulation, design, simulation, and construction of a coincidence demodulator. Chapter 1 explains the basic characteristics of frequency modulated (FM) signals and provides an overview of the required signal bandwidth, the signal spectrum, and the signal-to-noise ratio after demodulation. Chapter 2 describes each type of FM demodulator separately, and it includes all significant types of demodulator for FM radio broadcast. The function of the coincidence demodulator and its characteristics are explained in detail. Chapter 3 contains a theoretical solution of the phase shift network. Calculated values of the circuit elements are verified by simulation with a view to the total harmonic distortion of the demodulator output signal. Chapter 4 describes the front-end circuit of the receiver. Here, the filter design and the mixer circuit description are provided. The final part of the thesis presents the applicable laboratory task.
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Methods for quadrature modulator imbalance compensation
Povalač, Karel ; Valenta, Václav (referee) ; Maršálek, Roman (advisor)
Quadrature modulator (demodulator) is used in transmitting (receiving) part of many devices. Unwanted imbalance can influence amplitude, phase or DC offset of modulator (demodulator). Correction of imbalance was a main subject of thesis. Simulations of these methods were created in MATLAB and results were compared. Basics of methods were implement on programmable logic field by program Xilinx ISE. Development kit V2MB1000 with analogue board Memec P160 was chosen for this purpose. In the last part were compare simulation results with practical measurement.
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QAM Modulator
Duffek, Luděk ; Kubánek, David (referee) ; Číž, Radim (advisor)
The thesis focuses on consideration of possible ways how to realize multi-state modulators for a laboratory instrument. This instrument will illustrate signals, which partake on generation QAM modulation. The design of the laboratory instrument includes theoretic schemata and the execution of a prototype. There are theoretical facts of multi-state signals and multi-state modulations in this thesis. A simple block diagram of the laboratory instrument is made by the theory of creating quadrature amplitude modulation. For each block there are made several schemata, which are compiled to the global scheme. A printed circuit board and the structure items are made by the aid of the global scheme. The next part is devoted to a software facility for a used microprocessor, which ensures the whole function of the laboratory instrument. The final section deals with measuring, which checks the function of the modulator and the right setting coder’s constellation diagrams.
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Digital television broadcasting according to standard DVB-H
Pospíchal, Martin ; Prokopec, Jan (referee) ; Kratochvíl, Tomáš (advisor)
The bachelor work deals with problems of digital broadcast based on the standard DVB-H. It contains of the theoretic part and than there is the experimental part. The theoretic part compares the standard DVB-T with DVB-H in the introduction. Then comes after the theoretic explanatinon of the source coding of the picture and the standard for the coding the sound, channel coding and the modulation of the signal. Then it describes a scheme for metering the norm of DVB-H composed of a laboratory qauqing apparatuses and its brief describtion. Then comes after the description of the several metered and biased parameters and its impression on the quality and level of the recieved signal. The experimental part deals with the metering of the several parameters, that contains the description of the laid metering constellation diagrams, tables of the measured values, graphics dependences and evaluation of the concrete metering. The metering deals with the influence of the amplitude of the screened signal, phasic error, suppression carrier, amplitude imbalance, convolution code, guard interval and with the using the several modulations on a bit error rate BER, modulation error rate MER (S/N), the quality and the level of the received signal for the several TV channels.
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