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Laboratory workplace for measuring performances of DVB-T2/T2-Lite
Krejčíř, Dominik ; Kufa, Jan (referee) ; Polák, Ladislav (advisor)
This thesis deals with proposal and realization an appropriate measurement workplace to measure performances of DVB-T2 and DVB-T2-Lite. Both systems for terrestrial digital video broadcasting are described. It is possible to measure objective parameters and evaluate the quality of DVB-T2/T2-Lite signal subjectively. The proposed concept was verified by a set of experimental measurements, which is divided into four scenarios. The measurement focuses to parameters of Set-Top-Boxes. The measurement allows to test and compare Set-Top-Boxes.
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Model of physical layer of communication system IEEE 802.11af
Saprykin, Yaroslav ; Ulovec, Karel (referee) ; Polák, Ladislav (advisor)
Tato diplomová práce se zabývá analýzou, návrhem a simulací modelu fyzické vrstvy bezdrátového komunikačního systému IEEE 802.11af. V práci je především popsána vysílací část komunikačního systému s důrazem na zpracování IEEE 802.11af signálu. Následně je vytvořeno blokové schéma a model pro vysílací a přijímací části ve vysílacích módech SISO a MIMO. Model je realizován s grafickým uživatelským rozhraním v programovém prostředí MATLAB. Vytvořená aplikace slouží k prozkoumání vlastností IEEE 802.11af modelu na základě jeho systémových parametrů. Systémové parametry jsou volitelné uživatelem a aplikace poskytuje možnost simulace různých přenosových scénářů.
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Automated measuring system for irrigating plants with IoT connectivity
Lahoda, Vladimír ; Polák, Ladislav (referee) ; Kufa, Jan (advisor)
This bachelor thesis deals with IoT networks and considers their use as part of embedded devices. The purpose of this device is to control the flower bed or garden based by data from sensors monitoring the environment. The device not only controls the irrigation operation itself, but also sends all traffic data over the IoT LoRa network. Thus, the device also functions as a weather station, as all data are sent to a second device that acts as a receiver. This receiver displays the data and also sends them to the Internet, where the data are publicly available. The module for sending and measuring data is mounted on its own PCB and is covered in a waterproof cover, so they can be operated outdoors. There is an integrated battery, which is a backup of savings in case of power failure. The battery is designed to back up power for 25 days.
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Model of physical layer of communication system IEEE 802.11ah
Jurák, Petr ; Staněk, Miroslav (referee) ; Polák, Ladislav (advisor)
This diploma thesis deals with the analysis of the IEEE 802.11ah wireless communication system. For such a purpose, an appropriate simulation model in program environment MATLAB is created. The first part of thesis focuses on the IEEE 802.11 standard. Basic blocks of the transmitter and receiver are described. Attention is also devoted on the brief description of considered transmission channels. The second part contains the description of the proposed and realized simulation model in MATLAB. Individual blocks of the simulation model are described in details. Finally, the obtained simulation results are evaluated and discussed.
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Simulation of the DVB-C and DVB-C2 transmission and their comparison
Cibulka, Tomáš ; Hüttl, Ondřej (referee) ; Polák, Ladislav (advisor)
This Master thesis deals with description, analysis and simulation of standards of digital video broadcasting DVB-C and DVB-C2. There is described mainly the transmission system, channel coding, type of modulation and OFDM symbols generation. Furthermore, channel models, used for the exploring of their performances are described too. There was created an application with a graphical interface in MATLAB, which simulates transmission in DVB-C2. Based on simulations there are compared influences of each settings on bit error rate of data transmission for both standards. Finally, obtained simulation results are compared with theoretical values.
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Laboratory workplace for measuring performances of DVB-T2/T2-Lite
Youssefová, Kristina ; Kratochvíl, Tomáš (referee) ; Polák, Ladislav (advisor)
Tato práce se zaměřuje na zkoumání vlastností standardu pro digitální televizní vysílání přes pozemní vysílače (DVB-T2). Dělí na tři hlavní části. V první části je prozkoumán řetězec signálového zpracování DVB-T2. Ohled je rovněž brán na možný nepoměr I/Q v modulátoru OFDM. V druhé části je navrhnuté laboratorní měřící pracoviště pro měření vlastností systému DVB-T2. Ve třetí části je ověřena správnost navrhnutého postupu pomocí rozsáhlých experimentálních měření. Součástí této práce byl návrh laboratorní úlohy, která se zabývá měřením různých přenosových scénářů DVB-T2.
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Design of class AB stereo audio power amplifier
Zatloukal, Tomáš ; Polák, Ladislav (referee) ; Brančík, Lubomír (advisor)
The following work deals with design of class AB low-frequency amplifier, which is appropriately supplemented by correction Pre-amplifier and inrush protection circuit. The original schematic from prof. Leach was edited to fulfill task and to be easily completed from discrete components. The result of this work is the final design of power amplifier and correction pre-amplifier, protection circuit for speakers and power supply. As a next part, the design of printed circuit boards will be described together with assembling and mounting of boards in a construction box. Power amplifier will be verified by simulation and hardware measurements.
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Simulation of multipah propagation of multistate modulations
Polák, Ladislav ; Pust, Radim (referee) ; Šebela, Radek (advisor)
The diploma thesis Simulation of Multipath Propagation of Multistate Modulations is focused on the development of an appropriate algorithm in MATLAB environment, which is capable to simulate the impact of the multipath propagation on received signal (error rate) on the basis of given parameters of the transmission channels. Mechanisms and characteristics of the wave propagation in communication environment, types of digital modulations and their most important parameters are described in the first part of this thesis. The second part is focused on the simulation itself. Created GUI (Graphical User Interface) is able to display constellation diagrams of transmitted and received signals, as well as their bit error rate. It is also possible to compare these data with the data of signal, which is passed by a non-fading channel.
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Simulation of the RF transmission channel for the DVB-T2
Strouhal, Adam ; Hüttl, Ondřej (referee) ; Polák, Ladislav (advisor)
This Master thesis is focused on detailed description of the DVB-T2 system. This work deals with the description of the particular parts of models and with typical RF transmission channels for fixed and mobile reception. In order to simulate the impact of the fading transmission channels on the transmitted signal there was developed an appropriate application in MATLAB. The graphic user interface of this application allows set the transmission parameters of DVB-T2 and the parameters of the transmission channels. Results of simulations with various settings are evaluated and compared with the results, obtained from the DVB-T measurements.
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Subjective quality evaluation of video sequences
Krmela, Tomáš ; Fliegel, Karel (referee) ; Polák, Ladislav (advisor)
This master´s work is focused on the comparison of subjective assessment of the quality of video sequences. In this study, data are obtained by hardware and sofware techniques and they are compared. In the introduction, methods of video compressions are described. The main part of this work deals wtih the exploring of different methods of subjective assessment of the quality of video sequences. Finally, obtained results from different methods, are evaluated and discussed.
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