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Penetration Tests of Speaker Verification System
Nguyen, QuangTrang ; Rohdin, Johan Andréas (referee) ; Plchot, Oldřich (advisor)
The aim of this bachelor thesis is to create a penetration tests of speaker verification system with the use of the speech synthesis method. This work studies methods of spoofing against automatic speaker verification system. Before designing of the test set, the system and it's components that were used in this work are described. The last chapters of this work include a description of the process of designing the test set, realization of the designed test and the last part contains evaluation of the results and answers the question if it is possible to penetrate a verification system with the use of speech synthesis.
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Data transmition security with BCH codes
Frolka, Jakub ; Tejkal, Vladimír (referee) ; Němec, Karel (advisor)
The bachelor thesis Data transmission security with BCH codes deals with class of random error correction cyclic codes which are able to protect data in binary form. BCH codes operate over algebraic structures called Galois fields. Encoding of these codes is same as encoding cyclic codes and can be used cyclic shift register, but decoding is more complex and can be done with many algorithms, in this thesis are mention three: Peterson algorithm, Matrix method and Berlekamp-Massey algorithm. In this thesis are described characteristics BCH codes, their usage in communication devices and their posibility implementation. An example BCH code which is able to correct four independent errors is created. This example is used for presentation of encoding and decoding methods. In the end is described implementation of data protection codec for FGPA devices.
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Processing of MP3 files for DSP
Římský, Adam ; Sysel, Petr (referee) ; Herman, Ivo (advisor)
This thesys is concerned with create of compressed .MP3 files and their conversion back into PCM format. I describe individual parts of these operations for their maximal understanding by reader. Next part is generally about properties of DSP, their architecture, computation possibilities and about properties of used product by Analog Devices. In last part is showed implantation of decoder in DSP architecture.
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Protection of data transmission against long error bursts
Malach, Roman ; Lambertová, Petra (referee) ; Němec, Karel (advisor)
This Master´s thesis discuses the protection of data transmission against long error bursts. The data is transmited throught the channel with defined error rate. Parameters of the channel are error-free interval 2000 bits and length of burst error 250 bits. One of the aims of this work is to make a set of possible methods for the realization of a system for data correction. The basic selection is made from most known codes. These codes are divided into several categories and then the best one is chosen for higher selection. Of course interleaving is used too. Only one code from each category can pass on to the higher level of the best code selection. At the end the codes are compared and the best three are simulated using the Matlab program to check correct function. From these three options, one is chosen as optimal regarding practical realization. Two options exist, hardware or software realization. The second one would seem more useful. The real codec is created in validator language C. Nowadays, considering language C and from a computer architecture point of view the 8 bits size of element unit is convenient. That´s why the code RS(255, 191), which works with 8 bits symbols, is optimal. In the next step the codec of this code is created containing the coder and decoder of the code above. The simulation of error channel is ensured by last program. Finally the results are presented using several examples.
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Realisation of convolutional decoders
Šicner, Jiří ; Burda, Karel (referee) ; Němec, Karel (advisor)
This work deals with convolution codes. The work is divided into several parts. The introductory part contains basic description of convolution codes, their properties and distribution. There are briefly outlined some methods of decoding convolution codes. Another part of the proposal includes a specific code according to the award and implementation of decoder for this code. Then the full proposal is verified here by using Matlab Simulink. The last part includes a proposal for printed circuit encoder and decoder.
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Turbo codes and their applications in transmission technologies
Kuvik, Michal ; Číž, Radim (referee) ; Šilhavý, Pavel (advisor)
Purpose of this work is to clarify problems of anti-error security with the help of turbo codes. This work can be divided into two parts. In the first part we look at the theoretical aspect of features of turbo codes, their coding and at various approaches of decoding secure messages for example SOVA and MAP, also at analyzing usage of turbo codes in promising transmission technologies. Second part is focused on creating an application with the help of software Matlab and on verifying attributes of this method in this software.
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RDS messages decoder
Šipula, Martin ; Petržela, Jiří (referee) ; Prokopec, Jan (advisor)
This project engages in detailed description of radio data system (RDS). It explains basic principles of system's functions and its usage. Part of this project is also proposal of message decoder and its implementation.
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FITkit as a Remote Controller Transceiver
Růžek, Michal ; Strnadel, Josef (referee) ; Vašíček, Zdeněk (advisor)
The bachelor's thesis is about communication protocols used in infrared remote controls of consumer electronics. It describes widely used protocols such as RC5, NEC and SIRC, their properities and methods of decoding. Transceivers are realized via components inside FITkit's FPGA chip, using simple HW module. Demo application written in C language is also included.
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Realisation feasibilities of punctured convolutional encoders
Šedý, Jakub ; Zeman, Václav (referee) ; Němec, Karel (advisor)
The aim of this thesis is to bring readers the issue punctured convolutional codes and in the design and verification of the functionality of the codec as a separate electronic system. The thesis is divided into four main chapters. The first three chapters deal with design and implementation of individual blocks of the codec and the subsequent verification of these blocks. The fourth and last chapter deals with the design and implementation of the codec as a separate electronic system.
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Expansion Module with MP3 Files Decoder for FITkit Platforma
Brada, Miroslav ; Bartoš, Pavel (referee) ; Šimek, Václav (advisor)
Aim of this project is building of expansion module which expands capabilities of FITkit platform by allowing decoding of MP3 files. This thesis summarize knowledge about current audio encoding formats, available decoders and FITkit platform. Later part of thesis describes design procedure of expansion module for this platform, which was completed, although unsuccessfully. Module is using VS1063 codec. The end of thesis describes possible expansions in case of successful implementation.
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