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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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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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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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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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