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Identification and Decoding of Wireless Communication Using SDR
Matulka, Filip ; Bidlo, Michal (referee) ; Vašíček, Zdeněk (advisor)
The goal of this thesis is to create the system that uses concept of software defined radio. This system is capable of automatically identifying the communication parameteres and subsequent decoding of wireless communication. The thesis focus on the wireless system operationg in unlicened frequency band and cosidering fundamental modulation metods. The result is tested on two independent wireless systems that verify ability to automatically identify the communication parameters.
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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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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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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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QR Reader for Android
Loskot, Radim ; Široký, Vít (referee) ; Maršík, Lukáš (advisor)
This bachelor thesis focuses on the topic of reading the QR codes with the aim of designing and description of the implementation of QR codes' reader application for Android mobile platform. In theoretical part it analyzes structure of the QR codes including the way of information encoding and states the possible reference approaches of decoding them. With regard to the target platform Android it proposes algorithms for the detection of QR codes in the real time image and for decoding of the captured image from a mobile phone camera. At the end it evaluates the reliability and efficiency of the implemented functionalities and considers possibilities of their further development.
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Error protection of data transmission using BCH Codes
Kašpar, Jaroslav ; Křivánek, Vítězslav (referee) ; Němec, Karel (advisor)
The thesis Data transmission error-protection with BCH codes deals with a large class of random-error correcting cyclic codes which are able to protect binary data and can be used for example in data storages, high speed modems. Bose, Chaudhuri and Hocquenghem (BCH) codes operate over algebraic structures called Galois fields. The BCH encoding is the same as cyclic encoding and can be done with linear feedback shift register but decoding is more complex and can be done with different algorithms - in this thesis there are two algorithms for decoding Peterson and Berlekam-Massey mentioned. The aim of this thesis is to find BCH code which is able to correct t = 6 independent errors in up to data sequence n = 150 bits, then peruse possible realizations of the codecs and set criteria for the best realization, then design and test this realization. This thesis is split into three main parts. In the first part there are encoding and decoding methods of the BCH code generally described. The second part deals with selecting of the right code and realization. There was chosen BCH (63,30) code and realization with FPGA chip. In the last part is described design of BCH encoder and decoder and compilation in the Altera design software.
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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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Morfological and phonological awareness as predictors of reading literacy
LIETAVCOVÁ, Martina
The dissertation is engaged in reading pre-literacy difficulties from the point of view of psychological and psycholinguistic, particularly the factors that influence the development of reading literacy before children start to attend elementary schools. The aim is to analyze the factors which are considered as fundamental to the development of pre-reading skills, and above all it emphasizes phonological and morphological factors. Morphological factors seem to be applicable in transparent, consistent orthographic systems, that also include the Czech language environment. The empirical part presents the results of quantitative survey made with some children before starting their elementary education. It is followed by thorough longitudinal examination of pupils when the influence of morphological reading skills is observed. The results showed that the influence of morphological awareness in the Czech language environment is comparable to the predictable effect of phonological awareness. However, both types of the predictors appear in a different way, according to various reading parameters. Phonological awareness is closely related to decoding (especially to the speed of reading), on the other hand morphological awareness is related to reading comprehension. While testing the child´s comprehension, two various circumstances were distinguished, loud and quiet reading. While reading loud the position of morphological awareness is a lot more dominant compared to the position of phonological awareness. By the appearance, the predictable effect of morphological and phonological awareness was changing if the two predictors were studied individually or as the set of all the used predictors. The study of research helps to recognize the "backward" children having big problems with morphological skills that can endanger their further development of reading. The results have been put in context along with the professional Czech and foreign literature data.
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