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Radiation pattern shaping of the optical transmitter
Csonka, Gábor ; Němeček, Jiří (referee) ; Wilfert, Otakar (advisor)
This work deals with questions of space assembling of several optics beams. There are mentioned the base features and values of space distribution of beam intensity in laser beam. The forms of diffusion of space localized light that is described by beam optics. There is a characterization of Gaussian beam, and diffraction of several beams. There is mentioned a simulation an assembling of two and more beams. It contains model of assembling incoherent beams. The work also includes suggestion of final layout of laser beams, which form optical transmitter with radiating characteristics, resistant to defects evoked by atmosphere.
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Coexistence of the communication systems in ISM band
Nowak, Dan ; Kejík, Petr (referee) ; Prokopec, Jan (advisor)
The purpose of this work is to study the physical layer technology of the communication systems working in the ISM band, to describe coexistence mechanisms in the selected frequency band, consequently to create models of the physical layers in the Simulink interface, to simulate synchronous transmission of the devices and to modify the model in order to correspond with coexistence mechanisms described in IEEE standard 802.15.2. The practical part of this paper examines the effect of Wi-Fi device output power on the transmission speed during synchronous transmission with Bluetooth device.
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Coexistence of wireless systems LoRa and Bluetooth
Paul, Filip ; Kratochvíl, Tomáš (referee) ; Polák, Ladislav (advisor)
Bakalářská práce je zaměřena na koexistenci LoRa a Bluetooth technologií v bezlicenčním 2.4 GHz ISM pásmu. Práce se skládá ze dvou hlavních částí, jmenovitě teoretické a experimentální. Ve své teoretické části se věnuje popisu fyzické vrstvy obou systémů a definuje koexistenční scénáře, které mohou mezi oběma systémy nastat. V experimentální části je navržen a zrealizován měřící testbed pro měření koexistenčních scénářů, které mohou nastat mezi LoRa a Bluetooth systémy v 2.4 GHz ISM pásmu včetně následného zpracování naměřených dat. Na závěr je navrhnuta laboratorní úloha a založená na experimentální části diplomové práce, která slouží pro edukativní účely pro kurz mobilních komunikací vyučovaný na univerzitě VUT.
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Dynamic laser interferometer
Chovaneček, Libor ; Drexler, Petr (referee) ; Fiala, Pavel (advisor)
The theme of this bachelor´s project is dynamic laser interferometer. The project is firstly focused on theory, where it explains the term of interference and principle of operation of interferometer on specific types of interferometers. Different types of lasers used in interferometers are mentioned there. The next part of this paper is focused on assemblage of interferometer with description of particular parts. There are mentioned two methods of signal processing. The last part deals with confirmation of proper functioning of measuring system.
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QoS optimization and modern communication services delay analysis
Novák, Přemek ; Škorpil, Vladislav (referee) ; Endrle, Pavel (advisor)
This thesis consists of theoretical and practical parts. The theoretical part contains an analysis of the problems of wireless networkssolutions individual standards and methodologies to ensure quality of service. In the practical part using the OPNET Modeler, a number of different simulation models and their evaluation. It is a model of individual standards, support mobility and interference effects on quality of service.
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Computer modelling of data transfer over power lines
Křivka, Petr ; Mlýnek, Petr (referee) ; Mišurec, Jiří (advisor)
The master‘s thesis is focused on data transfer over power lines. The influence of connected devices on data signal is studied. In this thesis, you can find the descriptions of PLC technology characteristics, sources of signal interruption and, mainly, the method of modelling the PLC channels as a multipath signal propagation environment is thoroughly discussed. There are models of PLC channels using this method projected in Simulink. The analysis of the influence of connected devices to bit error rate of a signal is processed. The devices are modelled by connected impedance.
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Wireless transmission interference modeling (AWGN, Rayleigh, Rice fading channels)
Hloušek, Tomáš ; Gleissner, Filip (referee) ; Mikulka, Jan (advisor)
This thesis describes and models wirelesss transmission intereferences in real communication channels. A signal received on a fading channel is subjected to a multiplicative distortion and to the usual additive noise. Real channel adds to the signal noise and fadings. Gaussian noise is a result of channel awgn. Fadings is implicated by multipath propagation of signal in Rayleigh and Rician channels. Main goal of this project is to program BERsolve, which is created in tool GUIDE in Matlab. User program BERsolve makes it possible to analyse bit error rate and symbol error rate for some types of channel models, which are defined by standard COST207. BERsolve offers some other functions i.e. display time behaviour, constellation diagram and spectrum. This program provides us with an overview representation of problem by multipath interferences in communication channels.
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Nonlinearity in the course of acqusition date in optical coherence tomography
Kadla, Jan ; Kolář, Radim (referee) ; Kuna, Zdeněk (advisor)
This bachelor thesis builds on my semestral work, thus provides a description of the problem of optical coherence tomography imaging system in terms of a brief historical development, structural parts and modifications. Previous work is supplemented by a more detailed description of data acquisition and especially signal processing. I present examples of the clinical and research application of this technology, and try to objectively refer to its advantages and disadvantages. Chapter dedicated to the description of a practical measurement explains selected data collection procedure and clarifies their following processing. At the end of the work are summarized the results achieved, including the considerations of potential errors during the measurement.
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Light diffraction and interference in laboratory exercises
Dvořák, Tomáš ; Šicner, Jiří (referee) ; Škarvada, Pavel (advisor)
The main purpose of this semestral project is suggestion and construction the laboratory task for measuring interference and diffraction of light, which would be teached in laboratory of physics. According to gained informations about optical phenomenon, the physical construction of the laboratory task was made. Subsequently the CMOS camera was connected and installed. There was also developed a software for controlling this camera. Software is able to control all supported functions of camera, capture and save samples from live recording and show the intensity decomposition of captured images. The most important function of developed software is ability to measure distances between particular diffraction local extremes.
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Laser Doppler anemometry
Osička, Tomáš ; Lízal, František (referee) ; Jedelský, Jan (advisor)
This bachelor thesis deals with laser Doppler anemometry (LDA). It is a modern, non-intrusive flow measurement technique. The work deals with theoretical principles and components of the method. The experimental part is devoted to setting of the system. Vector plot and profile plot display the measurement results.
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