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Wireless transmission of flight data for low distance
Kučera, Petr ; Maršálek, Roman (referee) ; Prokopec, Jan (advisor)
This diploma thesis deals with the flight data wireless transmission from aircraft to the ground station. This is the data sent from the acrobatic aircraft during races, specifically the GPS position and data from sensors of acceleration and rotation of the aircraft. It dealt with the theoretical analysis of the radio link and design of device that receives radio transmission. In aircraft it is dealt with data capturing and their deployment through the radio module. Data are sending to another post-processing on the ground station after receiving. There are two solutions of radio module and in the last part is a solution for capturing data from more airplanes.
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Communication systems based on MB-OFDM
Škapa, Martin ; Šebesta, Vladimír (referee) ; Maršálek, Roman (advisor)
The aim of the Master’s Thesis is to describe ideas of the MB-OFDM principle that represents the possibility of OFDM principle implementation in ultra wideband systems. There are compared physical layers of the IEEE 802.15.3a and the ECMA-368 standard which include the MB-OFDM principle. In practical part of the thesis, there was created a model of ECMA-368 physical layer in MATLAB environment including CDMA access principle. Finally, the MB OFDM system resistance against disturbance and the Peak-to-Average-Power Ratio is analyzed and commented.
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Implementation of software radio into FPGA
Šrámek, Petr ; Maršálek, Roman (referee) ; Prokeš, Aleš (advisor)
The common objective of this project is implementation of software defined radio (SDR) into FPGA. The text contains review and comparison of several hardware concepts intended for SDRs implementation then the methods for digital implementation of various components of radios as the filters, mixers and others are mentioned. Part of the text introduces used hardware platform and describes software support for designing, simulations and implementation into hardware. Significant part of project describes complex of external hardware components as filter, amplifier and control panel designed and built within the project realization. But the main part of project demonstrates design of the software solution of radio receiver. There is specified architecture of radio for FM broadcast receiving, next the more complex systems with carrier recovery algorithm are presented. These systems are able to work with AM, BPSK and QPSK modulations. It is possible to implement all these receivers into hardware and verify their operation. The practical laboratory theme has been outlined within the project run.
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Pseudo-random sequencies in UWB systems
Laška, Richard ; Maršálek, Roman (referee) ; Prokeš, Aleš (advisor)
This master´s thesis deals with Ultra-wideband and reveals present stage of this technology and situation on marketplace. In this work I will mention the milestones of its history and describe main fundamentals of communication and modulation methods in UWB systems. This work provides an overview of methods in pseudo-noise code design. The practical part includes UWB system simulation based on BPSK modulation and Directsequence multi-access scenario. This work presents BPSK modulated signal behavior in UWB channel model, where AWGN noise and multi-path energy is taken into account. Only physical layer was tested. At the end of this thesis, the summary and conclusion simulation results will be discussed. Bit error rate characteristic is a product of this testing.
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Realization of OFDM coder for DVB-T system
Zelinka, Petr ; Maršálek, Roman (referee) ; Frýza, Tomáš (advisor)
The contents of this thesis is a delineation of the European Standard ETSI EN 300 744 for terrestrial digital video broadcasting (DVB-T) and a description of created OFDM coder and decoder for baseband signal transmission in 2K mode without error correction capabilities. The proper function of both devices is verified by means of Matlab simulations and practically implemented into Texas Instruments’ digital signal processor TMS320C6711 using Starter Kits.
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Communication link modeling
Škára, Michal ; Prokopec, Jan (referee) ; Maršálek, Roman (advisor)
This Master’s thesis subject is communication link modeling, what means exploring and subsequent connect of blocks QPSK modulator – raised cosine filter – quadrature modulator – nonlinear amplifier – quadrature demodulator – raised cosine filter – QPSK detector. All work proceeded in simulation world VisSim 6.0, manual of this software is opened in this thesis. Individual blocks are analyzed in this scheme including description and configuration. Main theme was exploring error rate of transmission in modulator imbalance, using nonlinear amplifier TWTA or in calculations in fixed and floating point. Theoretically is examined and practically implanted method of modulator imbalance compensation. Circuits with QPSK and 16QAM modulator were analyzed. Circuits are filled in with transparent tables and graphs. In the end of this thesis is applied to generating of source codes in C language by the help of upgrade C-Code, which can be useful in practical realization on DSP.
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Methods for quadrature modulator imbalance compensation
Povalač, Karel ; Valenta, Václav (referee) ; Maršálek, Roman (advisor)
Quadrature modulator (demodulator) is used in transmitting (receiving) part of many devices. Unwanted imbalance can influence amplitude, phase or DC offset of modulator (demodulator). Correction of imbalance was a main subject of thesis. Simulations of these methods were created in MATLAB and results were compared. Basics of methods were implement on programmable logic field by program Xilinx ISE. Development kit V2MB1000 with analogue board Memec P160 was chosen for this purpose. In the last part were compare simulation results with practical measurement.
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Digital predistorters for amplifier linearization
Kroužil, Miroslav ; Valenta, Václav (referee) ; Maršálek, Roman (advisor)
In this work I describe digital predistortion in baseband used for amplifier linearization. Non-linearity is one of the worst disadvantages of Power amplifiers and decreasing of its is useful from many reasons. Work examines system which contains: Data source, which is represented by QPSK or OFDM modulator, predistorter, Power amplifier (model of non-linearity) and unit used to update coeficients for predistorter adaptation. System is simulated in MATLAB and Xilinx (simulation by ModelSim). Results are compared, described and commented.
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Wireless transfer of the sensor data
Kičina, Andrej ; Maršálek, Roman (referee) ; Biolková, Viera (advisor)
Thesys is focused on wireless transfer of the sensor data. It describes different wireless standards for potential use and realization of interface between sensor's data and their transfer. Crux of the matter is in detailed description of whole system with created utility programs. In the end it is summarized acquiered features of the realization.
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OFDM implementation in FPGA
Horák, Martin ; Fedra, Zbyněk (referee) ; Maršálek, Roman (advisor)
The thesis is focused on designing OFDM modem, which should be implemented into the FPGA device. The advantages of using OFDM signals in order to provide high baud rates together with high multipath immunity has provoked a mass expansion into media systems such as DSL, DVB, Wi-Fi, WLAN, etc. . Thanks to this technology we can quarantee high modulation rates with minimal negative disturbance eects. The rst part is dedicated to characterise OFDM signals, their generation and the algorithm producing the OFDM which is implemented in DSP devices. For the purpose of using the fastest algorithm, the Fast Fourier Transform using Cooley-Tukey algorithm was shown. Before we can implement OFDM modem into the FPGA device, we have to simulate its correct function. Because there is no OFDM analyser available at our departement, its necessary to prove its correct function by simulations. Therefore a large part of this thesis is focused on simulations using Matlab and ModelSim, in order to show comparison between the theoretical, and simulated results. Between the theoretical and practical simulations there is a part which shows the brief characteristics of available FPGA devices. Detailed view is presented just for the Virtex II device, which the implementation is made for. As a suitable FPGA device, we have chosen Virtex II XC2V1000 which is available for students. In the last part the measured results were shown to prove the corect function of the modem. Programming the FPGA using VHDL language is realized in the software ISE Xilinx (distributed in Xilinx software support). All programmed scrits and data used in this thesis are included on distributed media.
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