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Turbo codes and their applications
Ploštica, Stanislav ; Krajsa, Ondřej (referee) ; Šilhavý, Pavel (advisor)
This Diploma thesis aims to explain the data coding using turbo codes. These codes belong to the group of error correction codes. We can reach the high efficiency using these codes. The first part describes process of encoding and decoding. There are describes parts of encoder and decoder. Principle of encoding and decoding demonstrate a simple example. The end of this part contains description of two most frequently used decoding algorithms (SOVA and MAP). The second part contains description of computer program that was made for using as teaching aid. This program was created in Matlab GUI. This program enables to browse error correction process step by step. This program contains graphic interface with many options and display results. In the third part is described program created in Matlab Simulink that was implemented into the TMS320C6713 kit and there is description of measuring procedure. For verification of efficiency of turbo codes was measured any parameters. Some of these parameters are: number of decoding iterations, generating polynoms and using of puncturing. The last part contains measured value and result evaluation.
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FM receiver with RDS-TMC decoder
Štohanzl, Milan ; Petržela, Jiří (referee) ; Prokopec, Jan (advisor)
The system RDS is dedicated to broadcast an additional information for VKV transceivers. This bachelor work is concerned with a construction and a description of FM receiver with RDS data decoder. The document disserts on concrete connection of a circuit and describes programs for microcontroler and computer. Further it shows possibilities of corrections of particular components of the receiver and the programs.
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Data transmition security with general linear block codes
Dzurenda, Petr ; Tejkal, Vladimír (referee) ; Němec, Karel (advisor)
This work deals with problematic basic characteristic common linear block codes, concretely with creation generating and controlling matrix and individual ways decoding common linear block codes and then are theoretic knowledge used in the next part bachelor’s thesis. Next part this work is bent on the concrete layout of common liner block code satisfactory specifications by submission. In this part it can by find way haw create generating matrix be able to correcting tree single errors then create control matrix for decoding and correct network for correcting errors. Programs are used in this work are explained there. In the end this part is example of coding and decoding. Lastly work is realization codec. In this part is description of coder and decoder realizations. This codec is simulating by program Matlab Simulink in part five. In last part are create boards of printed circuits by program Eagle for coder and decoder.
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Czech-English Translation
Petrželka, Jiří ; Schmidt, Marek (referee) ; Smrž, Pavel (advisor)
Tato diplomová práce popisuje principy statistického strojového překladu a demonstruje, jak sestavit systém pro statistický strojový překlad Moses. V přípravné fázi jsou prozkoumány volně dostupné bilingvní česko-anglické korpusy. Empirická analýza časové náročnosti vícevláknových nástrojů pro zarovnání slov demonstruje, že MGIZA++ může dosáhnout až pětinásobného zrychlení, zatímco PGIZA++ až osminásobného zrychlení (v porovnání s GIZA++). Jsou otestovány tři způsoby morfologického pre-processingu českých trénovacích dat za použití jednoduchých nefaktorových modelů. Zatímco jednoduchá lemmatizace může snížit BLEU, sofistikovanější přístupy většinou BLEU zvyšují. Positivní efekty morfologického pre-processingu se vytrácejí s růstem velikosti korpusu. Vztah mezi dalšími charakteristikami korpusu (velikost, žánr, další data) a výsledným BLEU je empiricky měřen. Koncový systém je natrénován na korpusu CzEng 0.9 a vyhodnocen na testovacím vzorku z workshopu WMT 2010.
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Data transmition security with Reed-Solomon codes
Šalanský, Jan ; Šporik, Jan (referee) ; Němec, Karel (advisor)
This Bachelor thesis deals with the security of data transmission by Reed-Solomon codes. It discusses the design of the code, coding method and primarily decoding facility. There are described particular phases of decoding: the computation of the Syndrome, determination of an error locator polynomial, finding of positions of false symbols by Chien search and calculation of error values using the Forney’s algorithm. It compares these basic algorithms to find the polynomial localization errors: Peterson-Gorenstein-Zierler algorithm, Berlekamp-Massey algorithm and the extended Euclidean algorithm. There is shown a detailed design and software implementation of a simple system with forward error correction based on these theoretical findings. Design of the system begins by selecting the appropriate Reed-Solomon code RS (63,39). Next step is construction of basic algebraic structures for this code and derivation of encoder and decoder. Design of system with forward error correction finishes by calculation of encoding and decoding. The final system with forward error correction has been programmed for platforms MS Windows and Linux. It has been based on previous calculations and examples in references.
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Tree Code Decoding Methods
Zamazal, Zdeněk ; Lambertová, Petra (referee) ; Němec, Karel (advisor)
This thesis deals with applying knowledge of data channel coding and concerns about possibilities of tree codes decoding. It describes several decoding methods and inquires their ins and outs. Basic knowledge of theory of information is necessary, it is presumed that reader is familiar with convolutional codes and coder definitions. Criterions for choosing decoding method are introduced and lightely described. A decoder is designed using method choosed by denoted criterions. Implementation of the decoder, using Matlab Simulink enviroment, has taken part in the thesis. Function of the decoder is verified in simulation.
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Adding New Words in a Dynamic Speech Recognition Decoder
Škrdlík, Kryštof ; Veselý, Karel (referee) ; Schwarz, Petr (advisor)
The result of this thesis is a modified speech recognizer developed by the company Phonexia, in which new words that are not part of its dictionary can be added dynamically. The chosen method that was implemented works by inserting finite automata with new words directly into a modified static recognition network describing combined language and pronunciation model of the recognizer in places that are specified in advance. This method offers comparable results with a speech recognizer without modification.
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Audio codecs and their perceptual quality evaluation
Hudec, Andrej ; Schimmel, Jiří (referee) ; Rajmic, Pavel (advisor)
The bachelor thesis deals with audio codecs and tests to evaluate their listening quality. The thesis offers a description of the properties of human hearing, a brief introduction to the issues of audio coding, types of audio data compression and listening tests. The bachelor thesis also contains a theoretical description of the coding processes of selected audio codecs, evaluation of measuring their computational complexity and evaluation of listening quality of each of them using listening tests. HTML, CSS, Javascript and Python programming languages were used to implement the listening test environment. The audio files examined in the listening tests were obtained using the FFmpeg library.
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