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Keeloq System Experiments
Kočíř, Michal ; Hajný, Jan (referee) ; Strašil, Ivo (advisor)
The bachelor thesis deals with security issues in wireless control. On this basis the laboratory task for experiments with Keeloq system is designed. The concept of laboratory task is justified and supplemented by processed documentation. In the first part of this thesis the principles of security and transfer of information for wireless technology are described. In the second part KeeLoq system is analysed. There are the principles of encoding and decoding of transmission of KeeLoq system telegrams described. KeeLoq 3 Development Kit of Microchip company is used for description of encoding and decoding. The next section deals with an attack on KeeLoq system by "brutal force", which is also demonstrated by generated code in programming language C. The third part provides the concept of laboratory tasks that includes introductory meditation, discussion on assigned elements, content and structure of laboratory task. Finally, the fourth part contains the documentation of lab experiments with KeeLoq system, whereby students work out laboratory task.
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Languages and Web Applications Encoding
Charvát, Jaroslav ; Jaša, Petr (referee) ; Kunc, Michael (advisor)
The point of this bachelor´s thesis is creation of web application, which shows using different char sets for various alphabets and languages. In proposal I describe the hardest part of this work. During implementation I had to largely modify proposal. Next I am concerned with analyzing technologies, which I used for realization. I am trying to explain realization parts of the work in part of this document I called Implementation. Application offer controlling in 10 languages.
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GSM-EDGE and UMTS Systems Coexistence
Gleissner, Filip ; Hanus, Stanislav (advisor)
The dissertation thesis deals with the investigation of the coexistence of GSM–EDGE and UMTS systems with focus on the physical layer of the systems. The aim is to provide a set of recommendations for practical cooperation while the systems operate in both the separated and the common radio bands. A detailed description of signal processing of both the systems on the physical layer is presented. On the basis of this description, models of both systems were created and implemented in the MATLAB environment. The simulations are focused on the physical layer quality parameters, especially the bit error ratio evaluation for various ratios of useful signal power to noise power during the transmission over the radio channel. Simulation is also used to examine the quality of received useful signal while it is interfered by signals from the same and adjacent channels. The purpose is to determine the isolation between these adjacent channels, when the bit error ratio of the useful signal does not exceed a certain reference value. The simulation results are subsequently subjected to comparison with the results of the experimental measurements in laboratory conditions. Before the measurements are carried out, a study of possible interference types is performed. Consequently, the crucial parameters of the measuring equipment used are verified. From the results of simulations and measurements, the proposal of a minimum and recommended carrier separation between both the systems is presented in order to efficiently utilize the assigned frequency spectrum. Furthermore, for the cooperation in both the separated and the common radio bands, the necessary precautions are given for reaching the required isolation and thereby inter-system interference minimization.
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Embedded QR code generator with a graphic OLED display
Lakomý, Tomáš ; Krajsa, Ondřej (referee) ; Hanák, Pavel (advisor)
This master’s thesis deals with coding information and QR codes generating. There is described operation principle of QR codes for this purpose, and design of the equipment. This device is able to encode the information received through the serial port and display it in the QR code on the OLED display. Microprocessor is part of the device, so there is outlined the procedure for programming and testing equipment.
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NEW CHANNEL CODING METHODS FOR SATELLITE COMMUNICATION
Rumánek, Jaroslav ; Levický, Dušan (referee) ; Žalud, Václav (referee) ; Šebesta, Jiří (advisor)
This dissertation thesis deals with new progressive channel coding methods for data transmission using satellite transponder. The design of the system for SMS transmission, in which novel turbo coding methods are applied, is discussed too. An achievement of the lowest output power and the smallest user aperture is the principal aim of the new method applications. Design of system that would be able to the error free SMS transmission by very low signal to noise ratio is analyzed in this dissertation thesis. The work is focused on energy budget, modification and implementation of new turbo code types and using unique properties, development of new bit error rate estimation methods and methods for determination of final SMS form. The main contribution is the new type of turbo code development that have optimal properties for this usage, development of new bit error rate estimation method and development of method that is able to determine final form of SMS on the basis SMS frame structure and turbo decoding theory when the bit error rate is not zero.
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Image Compression Using the Wavelet Transform
Bradáč, Václav ; Polok, Lukáš (referee) ; Bařina, David (advisor)
This work deals with image compression using wavelet transformation. At the beginning , you can find theoretical information about the best known techniques used for image compression , a thorough description of wavelet transormation and the EBCOT algorithm. A significant part of the work is devoted to the library's own implementation . Another chapter of the diploma thesis deals with the comparison and evaluation of the achieved results of the processed library with the JPEG2000 format
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Simulation of ADSL error protection systems
Bernat, Zbyněk ; Krajsa, Ondřej (referee) ; Šilhavý, Pavel (advisor)
The main objective of this thesis was to create a model of forward error correction (FEC) system used in ADSL modem, which will be able to check its individual settings using the test methods specified in Recommendation G.996.1. The work is divided into two basic parts – theoretical and practical. The first part describes the basic functional characteristics of ADSL system, with attention being paid to aspects affecting the activity and setting of the error protection system. There are also discussed the theoretical basics of FEC coding techniques used in ADSL. The work also contains a description of the method for testing DSL system resistance against impulsive interference, which is specified in Recommendation G.996.1. The practical part of this thesis contains a description of the proposed model of the FEC system. The model was implemented in the programming environment Matlab Simulink. The proposed model includes the simulation of FEC coding process, DMT modulation and transmission channel with the impulse interference and the background noise. The proposed program is able to calculate parameters for setting FEC system from the specified data transfer rates and the requirement for interleaving. In addition, allows you to set the parameters of transmission line and sources of impulse interference and of the background noise. Under the set of input characteristics of the transmission is calculated bit allocation and the resulting parameters are given to a computational core of the model. In the application can be performed two types of test tasks. The first one is based on the Recommendation G.996.1 and makes it possible to determine probability of errored second. The second test task is for the measurement of resistance of the transmission system against impulsive interference. The results of the simulations are summarized in the conclusion of work.
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Comparison of Multimedia Signal Compression Possibilities
Špaček, Milan ; Mišurec, Jiří (referee) ; Škorpil, Vladislav (advisor)
Thesis deals with multimedia signal comparison of compression options focused on video and advanced codecs. Specifically it describes the encoding and decoding of video recordings according to the MPEG standard. The theoretical part of the thesis describes characteristic properties of the video signal and justification for the need to use recording and transmission compression. There are also described methods for elimination of encoded video signal redundancy and irrelevance. Further on are discussed ways of measuring the video signal quality. A separate chapter is focused on the characteristics of currently used and promising codecs. In the practical part of the thesis were created functions in Matlab environment. These functions were implemented into graphic user interface that simulates the activity of functional blocks of the encoder and decoder. Based on user-specified input parameters it performs encoding and decoding of any given picture, composed of images in RGB format, and displays the outputs of individual functional blocks. There are implemented algorithms for the initial processing of the input sequence including sub-sampling, as well as DCT, quantization, motion compensation and their inverse operations. Separate chapters are dedicated to the realisation of codec description in the Matlab environment and to the individual processing steps output. Further on are mentioned compress algorithm comparisons and the impact of parameter change onto the final signal. The findings are summarized in conclusion.
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System for Recording Video from IP Videocameras
Travěnec, Jiří ; Michal, Bohumil (referee) ; Skokanová, Jana (advisor)
This diploma thesis focuses on multimedia streaming from IP cameras. Its main goal is to explain theoretical background of real-time streaming via computer networks, and describe development of a recording system. This recording system is meant to be used mainly in schools for lecture recording purposes. The thesis contains description on how a recording server application and web-based management system were developed. The theoretical part explains topics related to multimedia streaming, networking, and multimedia procesing, such as real-time streaming protocols, encoding, compression, network latency, network congestion and many others.
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Video and Data Services Quality in the Future Broadband Multimedia Systems and Networks
Kufa, Jan ; Hudec, Róbert (referee) ; Fliegel,, Karel (referee) ; Kratochvíl, Tomáš (advisor)
Téma doktorské práce je zaměřeno na analýzu zpracování signálů v širokopásmových multimediálních sítích a systémech budoucnosti, kde se předpokládají systémy s ultra vysokým rozlišením (UHDTV), vysokým snímkovým kmitočtem (HFR) a stereoskopické systémy (3D). Tyto systémy budou umožňovat vysoce účinnou zdrojovou kompresi obrazu, zvuku a dat a také jejich vysoce účinný přenos, a to jak při volném vysílání (např. DVB-T2), tak ve službách placené televize (např. IPTV). Cílem práce je analýza a vyhodnocení kvality obrazu a služeb v těchto systémech na základě objektivních metrik a subjektivních testů. Práce se dále zaměřuje na analýzu vnímané kvality u stereoskopické televize, kódovací účinnost moderních stereoskopických enkoderů a vlivu sekvencí na uživatelský komfort.
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