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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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Data transmition security with Reed-Müller codes
Hrouza, Ondřej ; Burda, Karel (referee) ; Němec, Karel (advisor)
The aim of this work is to propose a Reed-Muller code that secure data transfer to t = 4 independent errors, the information rate R ? 0,5 and for this code to produce a detailed proposal for implementation of the codec. In order to implement this proposal, it is necessary to familiarize themselves with the basic properties Reed-Muller codes. To understand the function of codec Reed-Muller code is in this thesis analyzed the process of encoding and decoding, which is based on a method of using the majority logic. For the design of codec, which consists of encoder and decoder, are used programmable logic circuits FPGA. These circuits are programmed in VHDL language, when for the design source codes is used Xilinx ISE 10.1. In thesis is examined in detail the structure and function of the encoder and decoder chosen Reed-Muller code and there are presented parts of the proposed source codes. Verify the functional ability of the codec is achieved by simulation in program ModelSim SE 5.7f. The simulation results together with the another proposal realization are output of this work.
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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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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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Acoustic Signal Recording and Processing Using B-Format Technology
Kurc, David ; Balík, Miroslav (referee) ; Schimmel, Jiří (advisor)
This bachelor’s thesis is focused on the system of recording and processing of acoustics signals called Ambisonics. It describes single sections of this system in the chain of acoustic signal processing. At most it is aimed at the B-format technology as the main ambisonic instrument, its encoding from the signals recorded with the special microphone capsule of the soundfield type or with help of encoding equations and its decoding into single speaker channels of various speaker arrays. The UHJ transmission format is also mentioned. The application B-format Decoder was created in the MATLAB programming environment. It consists of several functions and has friendly user interface, which provides the processing and decoding of B-format components for the speaker array with entered parameters. Among others this interface ensures loading, displaying, analysis and playback of source and resulting acoustic signals.
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Burst error correction in digital transmissions using Berlekamp -Preparata codes
Pfudl, Tomáš ; Pfeifer, Václav (referee) ; Němec, Karel (advisor)
Bachelor's thesis discusses properties of the systematic convolution codes for error-bursts correction. Berlekamp-Preparata code is a member of this group. Thesis aims at detail description of this code and for picked code designs a codec. Properties discussed at the first part of thesis are used at the second part for picking the code and designing the codec. For designing there are used various methods (programming scripts, simulation model). Codec design is described from properties of communication channel to hardware realization. Each step is exactly interpreted. Whole theoretical design is made in Matlab and for designing the hardware there is used program Xilinx.
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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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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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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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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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