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WLAN and Bluetooth Systems Coexistence
Mikulka, Jan ; Hanus, Stanislav (advisor)
The dissertation thesis deals with a WLAN and Bluetooth systems coexistence. A Bluetooth standard works in an unlicensed frequency band 2,402 – 2,480 GHz. This frequency band is also used by an IEEE 802.11b/g standard (Wi-Fi) which is the most extended representative of WLAN networks. Because Bluetooth and Wi-Fi systems operate in the same frequency band, a mutual signal degradation may appear, when devices are collocated in the same area. In the first part of the dissertation thesis there is a brief summary of 2,402 - 2,480 GHz frequency band regulations and its usage. There are described physical layers of Bluetooth and IEEE 802.11b/g standards and techniques used for a collision avoidance. The main part of the dissertation thesis deals with a development of a new Matlab Simulink model for investigations of the Bluetooth and Wi-Fi standards coexistence. Physical layer models and results of the coexistence simulations are verified by a measurement in real conditions with a help of a modern vector signal analyzer. The results are presented in a graphical form and a brief summary is attached at the end of each chapter. Corresponding tables of simulated and measured values are available in the enclosed CD.
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GSM-EDGE and UMTS Systems Coexistence
Gleissner, Filip ; Hanus, Stanislav (advisor)
The dissertation thesis deals with the investigation of the coexistence of GSM–EDGE and UMTS systems with focus on the physical layer of the systems. The aim is to provide a set of recommendations for practical cooperation while the systems operate in both the separated and the common radio bands. A detailed description of signal processing of both the systems on the physical layer is presented. On the basis of this description, models of both systems were created and implemented in the MATLAB environment. The simulations are focused on the physical layer quality parameters, especially the bit error ratio evaluation for various ratios of useful signal power to noise power during the transmission over the radio channel. Simulation is also used to examine the quality of received useful signal while it is interfered by signals from the same and adjacent channels. The purpose is to determine the isolation between these adjacent channels, when the bit error ratio of the useful signal does not exceed a certain reference value. The simulation results are subsequently subjected to comparison with the results of the experimental measurements in laboratory conditions. Before the measurements are carried out, a study of possible interference types is performed. Consequently, the crucial parameters of the measuring equipment used are verified. From the results of simulations and measurements, the proposal of a minimum and recommended carrier separation between both the systems is presented in order to efficiently utilize the assigned frequency spectrum. Furthermore, for the cooperation in both the separated and the common radio bands, the necessary precautions are given for reaching the required isolation and thereby inter-system interference minimization.
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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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Properties of the physical layer of ZigBee
Humpolík, Tomáš ; Frýza, Tomáš (referee) ; Prokopec, Jan (advisor)
The ZigBee standart works on using physical and data link layer of IEEE 802.15.4 standart. Three bands were defined (2.4GHz, 915MHz and 868MHz). There was also number of physical layers defined, each of them using one of the three bands and number of modulation and spreading functions. This thesis is focused first of all on specification 2,4GHz physical layer, which is world-wide used because this band can be used (with observace of the local rules) without license. Thesis is in its first part focused on modulation function, as well on used spreading functions and number of channels for each physical layer. In the second part is paid attention to demonstration kit by ATMEL Corporation, which enables associate a simple network in star topology and using the network for demonstration of simple functions of associated devices, and kit by Radiocrafts corporation, which is used in laboratory work. Laboratory work is focused on characteristics measurement during data transfer.
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ARM Cortex M4 Development board
Volek, Lukáš ; Macho, Tomáš (referee) ; Burian, František (advisor)
In this work I aimed at designing a universal system for testing either STM32F407/417 by STMicroelectronics and later various sensors and communication buses. The result then is a main board with many specific connectors for individual buses even with connectors making all I/O pins accessible at the same time. Thanks to advanced switching regulators the power supply is capable of accepting a wide range of sources like single Li-Ion cell, pair of alkaline cells, 12V Lead battery, common wall power adapters (both DC and AC up to 15 Vpp ), USB, laboratory power supplies with multiple outputs and finally POE (Power Over Ethernet). Supply voltages are supervised by voltage comparators with an optical signalisation. (It is possible to determine the sick branch without a measuring instrument and blowing components in the most cases.) Another important parameter was a robustness of the supply and communication lines. There is a number of TVSs, chokes, and big and low ESR capacitors A PC software is intended for a basic functionality demonstration only.
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Physical layer model of LTE system
Kounek, Milan ; Wieser, Vladimír (referee) ; Hanus, Stanislav (advisor)
Master’s thesis deals with the signal processing in LTE system, specifically focuses on the physical layer. The first part describes in detail the signal processing at the physical layer of the LTE system. Based on the acquired knowledge of signal processing is created a block diagram that graphically describes the process of the signal processing. Next part deals with the created mathematical model, which is programmed in Matlab. This section describes the limitations of the model, configuration options and view simulation results. The last part shows the results of simulations and analyzed the results.
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LTE system models
Navrátil, Petr ; Masopust, Jiří (referee) ; Hanus, Stanislav (advisor)
Master’s thesis is focused on part of mobile network named LTE. Project is analyzes the LTE physical layer, which is divided into four basic parts: Physical channels and modulation, Multiplexing and channel coding, Physical layer procedures, Physical layer measurements. Every part is described by actual 3GPP standard [1]. To understand the problem is expected a reader basic knowledge of OFDM systems, which the LTE system uses. The next part of this master’s thesis is dedicated to mathematic model physical layer of system LTE, created by program Matlab. This model is designed to measure errors in data transmission.
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Impact of Communication Parameters on Energy Consumption of Zigbee Devices
Popelka, Jan ; Červenka, Vladimír (referee) ; Šimek, Milan (advisor)
This thesis deals with the energy research and design a simple wireless sensor networks. The data modules with ZigBee wireless communication technology. The main feature of wireless sensor networks is the minimal energy devices at low cost and maximum data reliability. Furthermore, the work describes firmware for communicating nodes with the ability to change parameters of data transmission and thus affect the energy consumption node. Calculations of energy consumption, compared with the measured results, the discharge characteristics of the battery packs and lifetime broadcasting node is contained in the final chapters of this work.
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Signal processing in ZigBee system
Miloš, Jiří ; Bradáč, Zdeněk (referee) ; Hanus, Stanislav (advisor)
Master's thesis The Signal Processing in ZigBee System is focused on properties of Physical Layer of ZigBee (standard IEEE 802.15.4 - 2003). The work consists of three parts. The first part contains common view on using and properties of ZigBee. The next part focuses on the Medium Access Control Layer and in detail on the Physical Layer. There described signal processing in the Physical Layer in individual radio bands. The last part of the project contains the process of modeling in the MATLAB for both models of system ZigBee (bands 868/915 MHz and 2450 MHz). The last part of thesis deals with the simulations of BER depending on Carrier-to-Noise Ratio. Also examined the coexistence of systems operating in the same or a nearby frequency band. Based on the results of simulations there are given recommendations for the use of the ZigBee system in minimizing BER.
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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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