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Quality of Services in Optical Access Networks
Šifta, Radim ; Křepelka, Václav (referee) ; Vlček, Čestmír (referee) ; Filka, Miloslav (advisor)
The thesis focuses on the optical access networks and deals with the issue of transmission parameters of the physical layer, their negative impact on the quality of the services parameters and the possibilities of reducing their effect using the polarization multiplexing. The first and second chapter describe the theoretical background necessary for understanding the subsequent parts. The third chapter contains the practical part of the thesis. At first the optical routes in the Czech Republic in terms of polarization mode dispersion, which is together with insertion loss the main limiting parameter of high-speed optical networks, are evaluated. In the following part the measuring of the temperature changes effects on the polarization mode dispersion of the passive components and the effect of temperature changes to the polarization multiplexed signal are evaluated. To double the bandwidth and reduce the influence of polarization mode dispersion on the quality of services, the two simulation models of optical access networks using polarization multiplexing were carried out. These theoretical outputs were verified by the practical measurements in the laboratory and subsequently on the real optical route. Finally, a draft of the broadband optical access network based on wavelength and polarization multiplexing was designed based on obtained knowledge.
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Design of Effective Usage of Instructional System
Liška, Jiří ; Endrle, Pavel (referee) ; Škorpil, Vladislav (advisor)
In this bachelor thesis are proposed three new laboratory exercises using TIMS system. Laboratory exercises are focused on digital modulation, multiplexing and measurement errors in transmitting signals with line codes. The laboratory experiments were designed with respect to the practice of the subject matter in an article Access and Transport Networks.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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