National Repository of Grey Literature 71 records found  beginprevious31 - 40nextend  jump to record: Search took 0.01 seconds. 
Studies of Influences of Oscillators Frequency Instabilities in Satellite Communication Systems
Baran, Ondřej ; Baláž, Igor (referee) ; Šimša, Jan (referee) ; Kasal, Miroslav (advisor)
The dissertation thesis deals with a study of an influence of a simultaneous incidence of an additive thermal noise and a multiplicative phase noise on the useful signal transmission in narrowband satellite communication systems. While the additive thermal noise affects the useful signal only on the receiver side of the communication system, the multiplicative phase noise is produced in all system oscillators. One investigates how the receiver filter bandwidth reduction takes effect on the influence of individual noise types. The thesis is divided into four units. The first one (chapters 4 and 5) solves the ways of modeling of both noise types. In the second part (chapter 6), on the simple example, the primary analysis of the phase noise influence is made. Basic modulation schemes used in the satellite communication are also discussed (chapter 7). Third part (chapter 8) is devoted to the modeling of a general digital system with a M PSK modulation made directly on the main carrier wave. The last part (chapter 9) describes the modeling of a digital system with a BPSK modulation on the auxiliary subcarrier wave followed by an SSB modulation on the main carrier wave. General conclusions are deduced from obtained simulation results.
Simulation of the DVB-S2 Transmission
Klíma, Jindřich ; Fliegel, Karel (referee) ; Kaller, Ondřej (advisor)
This thesis is focusing on the second satellite digital TV standard, DVB-S2. It deals with the principle of the digital TV and the first standard DVB-S. It also describes the very beginning and characteristics of the DVB-S2, new technologies in use, architecture and the individual topics are then explained more in detail. The thesis also contains the program of transmission simulation of DVB-S2 in MATLAB. In the laboratory of television technology UREL, two standards were measured and compared with the values obtained from the program. The functionality of the program and the benefits of DVB-S2 were verified afterwards.
Laboratory Workplace To Measure Dvb-T2 Miso Signal
Bárta, Vojtěch
This article presents a laboratory workplace to measure DVB-T2 MISO signal under laboratory conditions. The performance of DVB-T2 MISO signal influenced by different transmission conditions can be evaluated in terms of the most commonly used objective parameters, like BER before and after channel decoding and MER. Functionality of the proposed concept and the adopted measurement methodology are verified by a set of experimental measurements.
Transmission of Digital Information over Audio
Bujnovský, Michael ; Malenovský, Vladimír (referee) ; Černocký, Jan (advisor)
Cílem této práce je umožnit přenést binární informace mezi dvěma zařízeními jen za pomocí zvuku. Práce začíná analýzou existujících řešení. Dále popisuje různé techniky digitální modulace, věnuje se synchronizaci a vlastnímu protokolu zapouzdřující data. Velkou částí práce jsou testy úspěšnosti přenosu za užití různých nastavení frekvencí a prostředí. Na základě výsledků testů je implementovaná uživatelská aplikace, umožňující demonstraci systému.
Performance Of Digital Audio Broadcasting In Mobile Reception Scenarios
Kresta, Daniel
This paper presents the Digital Audio Broadcasting (DAB) standard and its implementation into a simulation model. The negative influences of a transmission channel on the DAB signal are analyzed and emulated in the simulation with a focus on a mobile reception. Overall simulation model containing a transmitter, the transmission channel and a receiver was realized in a MATLAB environment. Multiple simulations of the DAB signal transmission in different conditions were performed and evaluated, with an emphasis on the mobile reception scenario. These results are presented along with a discussion.
Serial Bus Utilization For Smart Meters In Home Area Network
Slacik, Jan
This paper focuses on possibilities of using data from smart meters for home area network applications. Data communication between a smart meter and a consumer for home area network can be done directly witout dedicated communication channel for remote data acquisition. The seriál interface can be used for user data readout, depending on the support of the meters. This paper demonstrates experimental measurements of RS-485 serial bus, with the main objective to find a comparison of different bus configurations and different distances. The main contribution is recommendation of the best RS-485 setup of resistors configuration for home area networks.
Laboratory Workplace For Measuring Performances Of Dvb-T2/T2-Lite Systems
Krejčíř, Dominik
This paper presents a simple measurement setup to explore performances of DVB-T2/T2-Lite systems. The proposed concept is realized in a form of measurement workplace in laboratory conditions and an appropriate measurement methodology is adopted. It is possible to measure objective parameters of the DVB-T2/T2-Lite signal or evaluate its performance subjectively. Functionality of the proposed concept is verified by a set of experimental measurements.
Advanced modulation techniques for optical wireless communications
Šmída, Marek ; Janík, Lukáš (referee) ; Novák, Marek (advisor)
The bachelor thesis deals with modulations for optical wireless communications. Different types of modulations used in optical wireless communications are analyzed. The bachelor thesis discusses the implementing modulation techniques with the GNU Radio development environment. The bachelor thesis also analyzed error performace of modulation techniques.
Laboratory workplace for measurement of DVB-T2 MISO broadcasting
Bárta, Vojtěch ; Kratochvíl, Tomáš (referee) ; Polák, Ladislav (advisor)
This bachelor thesis deals with measurement and analysis of DVB-T2 MISO broadcasts. The theoretical part of the thesis describes the broadcasting chain of the DVB-T2 system at the level of the physical layers. Attention is paid to both SISO and MISO transmit modes. In the experimental part of the work is to design a measuring workplace for monitoring and analysis of DVB-T2 MISO transmission in laboratory conditions. The functionality of the proposed concept and chosen measuring methodology was verified by a set of experimental measurements.
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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