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Coexistence of LTE and LoRa in the 2.4 GHz ISM band
Potočňak, Martin ; Staněk, Miroslav (referee) ; Polák, Ladislav (advisor)
This diploma thesis deals with the study and measurement of coexistence scenarios that can occur between the LTE and LoRa systems in the unlicensed ISM band 2.4 GHz. A common radio frequency band in which LTE and LoRa systems can coexist is defined. An appropriate laboratory measurement is proposed and realized, allowing automatized measurement of the defined coexistence scenarios. For this purpose, a personal computer, professional measurement equipment and software MATLAB are utilized. Functionality of the proposed concept is verified by extensive measurements. The obtained results are graphically shown and discussed in detail.
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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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Coexistence of DVB-T2 and LTE in the 800 MHz band
Walach, Dominik ; Miloš, Jiří (referee) ; Polák, Ladislav (advisor)
This bachelor thesis deals with the study and evaluation of coexistence scenarios which can occur between DVB-T2 and LTE systems in the UHF band 800 MHz Both DVB-T2 and LTE systems are briefly described, and their common frequency bands are defined. An appropriate laboratory workplace is proposed and realized for the measurement, analysis and evaluation of the DVB-T2 and LTE coexistence scenarios. These systems work in adjacent or even in the same frequency bands. Thereby these systems can coexist, and different coexistence scenarios can occur.
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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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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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Signal propagation in wireless communication systems IEEE 802.11
Vyčítal, Jaroslav ; Fliegel, Karel (referee) ; Polák, Ladislav (advisor)
This paper deals with the propagation of waves. Here is the wavelength distribution according to the wavelength. It focuses on the UHF and SHF band in which IEEE802.11n operates. Contains model breakdown by cell type. Describes which propagation methods are dominant in the cell type. Several propagation patterns are presented, which are then modeled in Matlab environment.The models are then compared to experimental measurements.
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Model of physical layer of communication system IEEE 802.11af
Saprykin, Yaroslav ; Ulovec, Karel (referee) ; Polák, Ladislav (advisor)
This diploma thesis deals with analysis, modeling and simulation of the IEEE 802.11af wireless communication system on the physical layer. When designing the solution, it is necessary to understand in details the features and specifics of the IEEE 802.11af system. The work is primarily describes the transmitting part of the communication system with emphasis on processing IEEE 802.11af signal. Subsequently the block diagram and the basic model are created for the transmitting and receiving parts in SISO and MISO broadcast modes. The model is implemented with graphical user interface in the MATLAB programming environment. This application is used to explore the features and performance of the IEEE 802.11af based on its system parameters. System parameters are user configurable what allows to simulate different scenarios. The application also supports simulation of fading channel.
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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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Highly siderophile element and Re-Os isotopic geochemistry of carbonatites and associated alkaline rocks from selected occurrences in India
Polák, Ladislav ; Ackerman, Lukáš (advisor) ; Krmíček, Lukáš (referee)
Carbonatites are intrusive and extrusive rocks with content of carbonate minerals > 50% predominantly derived from upper mantle. They represent a potential economical source for platinum- group elements as can be seen on actively mined sites like Phalaborwa in South Africa or Ipanema in Brazil. The first complete dataset for highly siderophile element (HSE) abundances along with their 187 Os/188 Os compositions for carbonatites, silicocarbonatites and associated alkaline rocks (pyroxenite, syenite, monzogabbro and tonalite) from two Neoproterozoic (~ 800 Ma) suites from Samalpatti and Sevattur, Tamil Nadu region in south India is presented. The data were obtained by a standard methods in involving decomposition of samples in Carius Tubes, Os separation by CHCl3 following microdistillation and Ir, Ru, Pt, Pd isolation by anion exchange chromatography. The data show that carbonatites from Samalpatti and Sevattur are characterized by very low HSE contents, lower than other mantle-derived mafic melts such as basalts or komatiites. Suprachondritic OsN/IrN ratios might suggest that carbonatites are able to concentrate not negligible amount of Os. Due to high, non-uniform 187 Os/188 Os ratios, we suggest that the source of carbonatitic melts was largely heterogeneous with high contribution of crustal...
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Leachability and gastric bioaccessibility of contaminants from the waste products of Ni metallurgy
Polák, Ladislav ; Ettler, Vojtěch (advisor) ; Suchá, Veronika (referee)
Due to mining and processing of sulphide laterite and sulphide ore leads to environmental contamina- tion by metals and metalloid elements. To determine how the contaminant leached and how can da- mage its nearby area, serves leaching experiments. In order to determine the potential impact on hu-man health can be used in leaching tests simulated gastric, gastrointestinal and pulmonary solutions. The aim of this bachelor thesis is to make these leaching tests to determine how a metallurgical waste affect the environment or the population in the region (eg. workers in the steel industry). The results show that the greatest exhibit leachability have ash. The limit values for hazardous waste in excess of Ni (4250 mg/kg) for inert waste Zn (22.3 mg/kg) and Cd (0.51 mg/kg). Gastric leaching tests show that the greatest health risk exists for Al TDI (181 μg/day), Ni (BE 324 μg/day) and V (TDI of 0.78 μg/day). Tolerable daily intake (Tolerable Daily Intake, TDI) is the estimated amount that a person can endure in the long term without harming the body. Background exposure (BE) is the dose or amount, to which the individual is exposed to. As a result of the extraction to the surroundings gets more contaminants than would be obtained by natural processes (erosion, leaching by water).
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