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Optimization of the experimental NQR spectrometer
Segiňák, Ján ; Král, Bohumil (referee) ; Steinbauer, Miloslav (advisor)
The thesis deals with the NQR spectroscopy, which is one of the modern non-destructive measurement and diagnostic methods for the characterization of various materials. It is using a quadrupole moment - a property of atomic nuclei of certain isotopes. A method of nuclear quadrupole resonance (NQR) is in principle very similar to nuclear magnetic resonance (NMR). Thesis in the theoretical part analyse the principles of NMR and NQR, describes the possible use of this method to detect for example explosives, drugs, and other chemicals. In the following chapters are analysed the key parameters of NQR spectrometer and the principle of the chosen measurement method. The practical part deals with the individual components of NQR spectrometer, the design of possible improvements and programming of the measuring sequence. In the final chapter are processed the measurements of the submitted samples.
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Analysis of GSM network, using open source SW radio
Kilian, Petr ; Koutný, Martin (referee) ; Šilhavý, Pavel (advisor)
This master thesis is focused on analysis and creation of GSM network, using open-source projects. For such creation is used software defined radio – in this thesis kit USRP1 which uses OpenBTS with GNURadio. As a switchboard is used PBX Asterisk and for testing GSM network was used OsmocomBB (on Motorola C123) and Airprobe (on Nokia 3310) projects. Installation and implementation are part of this thesis. In thesis have been also created two scripts for simplify of the work with projects and one laboratory task.
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Spectrum sensing in the cognitive radio networks - influence of real communication link parameters
Lekomtcev, Demian ; Marchevský,, Stanislav (referee) ; Richterová,, Marie (referee) ; Maršálek, Roman (advisor)
The doctoral thesis deals with spectrum sensing in cognitive radio networks (CRN). A number of international organizations are currently actively engaged in standardization of CRN and it points out to the fact that this technology will be widely used in the near future. One of the key features of this technology is a dynamic access to the spectrum, which can be affected by many different harmful factors occurring in the communication chain. The thesis investigates the influence of selected factors on the spectrum sensing process. Another contribution of the work is the optimization of the Kolmogorov - Smirnov statistical test that can be applied for the primary user signal detection. The work also incorporates the analysis of the influence of the harmful effects caused by the commonly used transmitters and receivers on various spectrum sensing methods. The investigations are verified by the results of the simulations and also by the measurements with experimental platforms based on the software-defined radio (SDR).
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SDR-based UHF RFID communication analyzer
Vychodil, Josef ; Zamazal, Michal (referee) ; Povalač, Aleš (advisor)
Main topic of this thesis is development of software for capture and analysis of RFID communication in UHF band (standard EPC Class-1 Generation-2). One part of the work is focused on the basics of the RFID systems, software defined radio concept and graphical programming language LabVIEW. Main part of this thesis is discussing the developed software itself, its methods and principles. Next part is dedicated to present the graphical user interface of created application and its functionality. Last part of this thesis contains examples of captured and analysed processes in UHF RFID communication.
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Parameters of Communication Systems Based on OFDM-CDMA
Blumenstein, Jiří ; Kocur,, Dušan (referee) ; Baudoin, Genevieve (referee) ; Fedra, Zbyněk (advisor)
Cíl disertační práce leží v oblasti modelování a vyhodnocení bezdrátových komunikačních systémů s dvojrozměrným rozprostíráním signálu a jejich klíčových parametrů v závislosti na vybraných vlastnostech moderního bezdrátového komunikačního řetězce. Výzkumné metody použité v této práci spočívají především ve vývoji softwarového simulátoru pro prostředí Matlab, s jehož pomocí, a s využitím statistického přístupu, jsou navržené algoritmy ověřeny. Dále je použit simulátor fyzické vrstvy dle 3rd Generation Partnership Project Long Term Evolution (3GPP LTE), vyvinutý na Technické univerzitě ve Vídni. Tento představuje ideální platformu pro implementaci metody dvojrozměrného (2D) rozprostírání a její vyhodnocení s přihlédnutím k současným bezdrátovým komunikačním systémům. Zjištění prezentovaná v této práci představují především ověření účinnosti systému nazvaného jako Variable Spreading Factor - Orthogonal Code Frequency Division Multiplex (VSF-OFCDM), který využívá principu 2D rozprostírání signálu a zjištění, že VSF-OFCDM systém překonává systémy využívající Orthogonal Division Frequency Multiplex (OFDM), nebo Code Division Multiple Access (CDMA). Dále byla navržena metoda 2D rozprostírání signálu v systému LTE, kde se též potvrdila její účinnost. Díky účinnějšímu potlačení vlivu rychlé variace přenosového kanálu v závislosti na frekvenci a čase, dosahuje systém VSF-OFCDM znatelně vyšší datové prostupnosti.
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Algorithms for analysis and processing of RFID signals in FPGA
Harvánek, Michal ; Kováč, Michal (referee) ; Derbek, Vojtěch (advisor)
The result of this thesis is the architecture design for a software-defined radio, which is used to analyze the signal emitted by RFID tags in real time. The aim of this analysis is to measure the frequency characteristics of the RFID tag. The main means for achieving the objective of optimizing signal processing algorithms and reduce the time needed to control the hardware compared to the classical concept of SW radio USRP. It is described how to obtain and display digitally sampled signals using a graphical programming language LabVIEW and subsequent processing of these data in MATLAB. Further described is the skeleton of the proposed solution.
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Multicarrier modulator and demodulator for software defined radio
Klučka, Jaroslav ; Urban, Josef (referee) ; Maršálek, Roman (advisor)
This thesis deals with computer simulation of the communication chain using the OFDM modulation. In the beginning of my thesis there is a brief description of digital modulations, especially OFDM. The model of the transmitter, radio channel and receiver, including a simple timing and frequency synchronization and equalization is designed and simulated in the Matlab environment. There is a designed communication system implemented into USRP development board in the Simulink environment. The development board could not work simultaneously as a transmitter and as a receiver. Function of the transmitter was verified by measuring on spectrum analyzer. Testing OFDM signal using the arbitrary waveform generator CompuGen 4302 was generated for the verification of the function of the receiver. Testing signal was received and demodulated on the development board which works as a receiver.
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Global Positioning System Signal Emulator
Hofman, Jan ; Zamazal, Michal (referee) ; Povalač, Aleš (advisor)
Thesis is adressed to the principals of a satellite navigation. It is focused on a determination of a longitude, latitude and altitude of a single point on the surface of the Earth. It contains analysis of navigation messages and a manner of processing of navigation signals in GPS receivers. Realization of an emulator of the navigation signal of GPS system in Matlab is also described. The purpose of this emulator is a generation of navigation messages, which could be transmitted by universal software radio. The last part of thesis contains the analysis of these signals, which were captured by second software radio.
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