Národní úložiště šedé literatury Nalezeno 4 záznamů.  Hledání trvalo 0.01 vteřin. 
Simulace vícecestného šíření vícestavových modulací
Polák, Ladislav ; Pust, Radim (oponent) ; Šebela, Radek (vedoucí práce)
Práce Simulace vícecestného šíření vícestavových modulací je zaměřen na vývoj vhodného algoritmu v prostředí MATLAB, který je schopen na základě zadaných parametrů přenosových kanálů simulovat vliv vícecestného šíření na přijímaný signál (chybovost). V první části práce jsou uvedeny mechanizmy a vlastnosti šíření vln v komunikačním prostředí, rozdělení typů digitálních modulací a jejich nejdůležitější parametry. Druhá část práce se už zabývá samotnou simulací. Vytvořené uživatelský přívětivé rozhraní (GUI) pro vstup a výstup dat simulátoru umožňuje zobrazení konstelačních diagramů vyslaného a přijímaného signálu a také bitovou chybovost. Tyto údaje je vždy možné porovnat s průběhem signálu v bezúnikovém kanálu.
Analysis and Simulation of the Signals Transmission in the DVB-H/SH Standards
Polák, Ladislav ; Rupp, Markus (oponent) ; Grgic, Songa (oponent) ; Kratochvíl, Tomáš (vedoucí práce)
This dissertation thesis deals with the analysis, simulation and measurement of the signal processing and transmission in DVB-H and DVB-SH standards. These standards are based on the assumption that signal reception is characterized by the transmission channels with echoes. These, so called fading channels, are mainly characterized by the path delays and path losses. Depending on the other, additional features (speed of the receiver, Doppler spectrum, etc.), it can be possible divided these channels onto three main groups: mobile, portable and fixed. Of course, signal transmission in different transmission channel models are affected differently. Therefore, it is needed found the optimal system parameters in both, DVB-H and DVB-SH standards, for the quality reception of the broadcasted mobile TV services, which is the main goal of this thesis. For this purpose, two appropriate applications (one for DVB-H and one for DVB-SH) with GUI were created in MATLAB, which enable simulated and analyzed the signal distortions in mobile, portable and fixed transmission scenarios. Moreover, these applications also contain a second application with GUI for the easy set and modification of the parameters of the used channel models. Therefore, it is possible to evaluate the effect of parameters of whole system and channel models on the achieved error rate (BER and MER) and quality of the transmission. In all mentioned transmission scenarios, the signal distortions (depending on the Carrier-to-Noise ratio) were obtained, evaluated and discussed in this dissertation thesis. Furthermore, in case of DVB-H, all obtained results from the simulations, were verified by the measuring. Differences between the obtained results (simulation and measuring) are also discussed. This dissertation thesis can be divided into four main parts. The first part of this dissertation thesis, after the short introduction, deals with present state-of-the-art and literature survey in mobile broadcast DVB-H/SH standards. At the end of this part are clearly outlined the main aims of this dissertation thesis. Second part is focused on the brief description of the functional block diagram of transmitters in both, DVB-H/SH standards. Furthermore, there are briefly described the transmission fading channel models, which are commonly used for the modeling of the signal transmission. The brief description of program applications with flowcharts, appropriate for the simulation of the transmission in the DVB-H/SH standards, are presented and described in the third part of this thesis. Finally, the fourth and longest part of this thesis is focused on the evaluation and comparison of obtained results from the simulations and measurements.
Analysis and Simulation of the Signals Transmission in the DVB-H/SH Standards
Polák, Ladislav ; Rupp, Markus (oponent) ; Grgic, Songa (oponent) ; Kratochvíl, Tomáš (vedoucí práce)
This dissertation thesis deals with the analysis, simulation and measurement of the signal processing and transmission in DVB-H and DVB-SH standards. These standards are based on the assumption that signal reception is characterized by the transmission channels with echoes. These, so called fading channels, are mainly characterized by the path delays and path losses. Depending on the other, additional features (speed of the receiver, Doppler spectrum, etc.), it can be possible divided these channels onto three main groups: mobile, portable and fixed. Of course, signal transmission in different transmission channel models are affected differently. Therefore, it is needed found the optimal system parameters in both, DVB-H and DVB-SH standards, for the quality reception of the broadcasted mobile TV services, which is the main goal of this thesis. For this purpose, two appropriate applications (one for DVB-H and one for DVB-SH) with GUI were created in MATLAB, which enable simulated and analyzed the signal distortions in mobile, portable and fixed transmission scenarios. Moreover, these applications also contain a second application with GUI for the easy set and modification of the parameters of the used channel models. Therefore, it is possible to evaluate the effect of parameters of whole system and channel models on the achieved error rate (BER and MER) and quality of the transmission. In all mentioned transmission scenarios, the signal distortions (depending on the Carrier-to-Noise ratio) were obtained, evaluated and discussed in this dissertation thesis. Furthermore, in case of DVB-H, all obtained results from the simulations, were verified by the measuring. Differences between the obtained results (simulation and measuring) are also discussed. This dissertation thesis can be divided into four main parts. The first part of this dissertation thesis, after the short introduction, deals with present state-of-the-art and literature survey in mobile broadcast DVB-H/SH standards. At the end of this part are clearly outlined the main aims of this dissertation thesis. Second part is focused on the brief description of the functional block diagram of transmitters in both, DVB-H/SH standards. Furthermore, there are briefly described the transmission fading channel models, which are commonly used for the modeling of the signal transmission. The brief description of program applications with flowcharts, appropriate for the simulation of the transmission in the DVB-H/SH standards, are presented and described in the third part of this thesis. Finally, the fourth and longest part of this thesis is focused on the evaluation and comparison of obtained results from the simulations and measurements.
Simulace vícecestného šíření vícestavových modulací
Polák, Ladislav ; Pust, Radim (oponent) ; Šebela, Radek (vedoucí práce)
Práce Simulace vícecestného šíření vícestavových modulací je zaměřen na vývoj vhodného algoritmu v prostředí MATLAB, který je schopen na základě zadaných parametrů přenosových kanálů simulovat vliv vícecestného šíření na přijímaný signál (chybovost). V první části práce jsou uvedeny mechanizmy a vlastnosti šíření vln v komunikačním prostředí, rozdělení typů digitálních modulací a jejich nejdůležitější parametry. Druhá část práce se už zabývá samotnou simulací. Vytvořené uživatelský přívětivé rozhraní (GUI) pro vstup a výstup dat simulátoru umožňuje zobrazení konstelačních diagramů vyslaného a přijímaného signálu a také bitovou chybovost. Tyto údaje je vždy možné porovnat s průběhem signálu v bezúnikovém kanálu.

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