National Repository of Grey Literature 126 records found  beginprevious107 - 116next  jump to record: Search took 0.00 seconds. 
DC/DC converter
Němec, Martin ; Kuzdas, Jan (referee) ; Procházka, Petr (advisor)
This project deals with transistorized converters in particular a four-quadrant bridge. The main part of project discusses the drivers of transistors and a possible way of controlling a converter. The proposal of control electronics and the regulation structure are involved in the second part. This project also includes a construction of an apparatus which will be used as a teaching material.
Adaptive OFDM
Nowak, Dan ; Valenta, Václav (referee) ; Maršálek, Roman (advisor)
The purpose of this paper is to study the possibilities of the OFDM system adaptive modulation. The study presents mechanism for acquiring the necessary data of every frequency subchannel using pilot signals and application of these data for system adjustment. The paper introduces the water-filling principle for subchannel power allocation on the basis of their SNR and adaptive modulation mechanisms for variety of OFDM usage. These mechanisms are implemented into a MATLAB model. The code is then transformed into graphical representation and using USRP2, the signal is transmitted by real world channel.
Power line parameters
Kavan, Pavel ; Krajsa, Ondřej (referee) ; Mlýnek, Petr (advisor)
At the beginning is diploma thesis focused on a distribute power line parameters measurement and examination changes of this parameters depending on using of various power line cables. On the basis of measurements is made a transmission channel in Matlab & Simulink, where are executed simulations with power transmission line. The simulated power line is based on measured distribute parameters or physical proportions of cabels. By changing different parts of simulated communication channel is a symbol error rate expressed on the lenght of transmission line.
Modulated signal generator
Melša, Ondřej ; Poměnka, Petr (referee) ; Maršálek, Roman (advisor)
This project occupies with the creation modulated signal generator in MATLAB. There are explicit basic princips of modulation PSK, M-QAM, princip of system with spread spektrum and princip of access OFDM and MC-CDMA. Next there are explicit basic parametres and possibilities configuration of conversion analog PCI card CompuGen 4302, which serves as D/A convertor of signals created by PC.
Transmission analysis and measurements in digital television DVB-S/S2
Kaller, Ondřej ; Ulovec,, Karel (referee) ; Kratochvíl, Tomáš (advisor)
This master’s theses consists of theoretical introduction which includes basic search of referenced literature about digital television systems and picture quality classification. The results of signal character measurement of selected TV channels from satellites ASTRA 1E (DVB-S) and ASTRA 1L (DVB-S2) are provided. The energy budget calculation of downlink and results of 24-hour TS error rate measurement is included as well. The video quality by DVQL metric for each particular program of CS link stream was measured during full 24 hours.
Modelling of PLC system to ensure the reliability of communication
Procházka, Vít ; Mišurec, Jiří (referee) ; Mlýnek, Petr (advisor)
The master´s thesis is focussed on principles and characteristics of Powerline Communications (PLC), practical usage possibilities and advantages and disadvantage of it. There are described mudulations and a channel encoding which are in PLC used. The main part of the thesis deals with a design of a channel as transfer function through the use of two methods, an echo model and the ABCD matrix. After finishing of the design of transfer function the model of communication was created in the Matlab-Simulink program. There were used the narrowband modulations in the model and analyzed the bit error rate of the tranfer data. In the end all results were treated graphically and evaluated.
Navigation systems
Jirkovská, Šárka ; Stejskal, Vojtěch (referee) ; Pust, Radim (advisor)
This bachelor´s thesis is focused on the navigation systems GPS, Galileo and their development. The work describes the functions and parameters of mentioned navigation systems including individual modulation techniques, used frequencies and signal securing by encoding. Segments of navigation systems GPS and Galileo, which divide into control and space parts, are mentioned next. The principle of signals generation by GPS system satellites, where the navigation message is the basis of user´s data transfer, is introduced. The principle of generation of the navigation message is described as well as its structure and characteristics of used CA-code and P-code. Next part of the work presents the components of the Galileo navigation system satellites and conspectus of planned services of this system. The summary of used receivers’ characteristics and summary of selected producers of digital geographical data for navigation devices follow next. The last part mentions the simulation of signal generation of GPS satellite. The simulation includes encoding and decoding of navigation message. This simulation is created in Matlab version 7.4 environment.
TV Remote Controller
Bordács, Balázs ; Hála, Ondřej (referee) ; Hermany, Jiří (advisor)
This master’s thesis deals with parameters of the TV Remote Controller. Aim of this work is studying standards of remote controling of TV receiver by the way of infra-red light. For succesful solving of this project is important to learn about the theory of IrDA. In the second part ot this thesis is designed measurement unit for measuring the parameters of the remote control. The measurement unit includes an integrated IR receiver and photodiode for receive IR signals from remote control. The description of measurement unit blocks and principles of measuring parameters are also placed there. The final part is devoted to processing the measurement results of measuring levels and time waveforms of signal in the receiver module, directional characteristics of remote control and receiver. For measuremented unit is created laboratory task including the role specification and protocol.
Classification of digital modulation type
Balada, Radek ; Kováč,, Michal (referee) ; Povalač, Karel (advisor)
The aim of master’s thesis is a classification of digital modulation type. The interest in modulation classification has been growing for last years. It has several possible roles in both civilian and military applications such as spectrum sensing, signal confirmation, interference identification, monitoring and so on. Modulation classification is an intermediate step between signal detection and successful demodulation. Therefore the known methods are based on different statistics obtained from received signals. These statistics can be derived from continuous time signals and they hold for sampled signals.
Optimization of data communication over high-voltage lines
Minárik, Peter ; Krajsa, Ondřej (referee) ; Mlýnek, Petr (advisor)
The thesis deals with analysis of the PLC (Power Line Communication) system for data communications through powerlines. In the introduction describes the technology of data transmission through the energy network and is divided into categories corresponding with the explanation of the various specifications and features. Different types of coding, affecting the transmitted signal interference and modulation techniques used in a PLC are also described. The practical part is made up of telecommunications network model with transmission channel realized as additive white noise. The model can setup different types of modulation and coding in relate with the signal to noise ratio and bit error rates. The individual blocks settings are described in detail. The model was simulated. The results of simulation are displayed and evaluated at the end of work.

National Repository of Grey Literature : 126 records found   beginprevious107 - 116next  jump to record:
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