|
|
An Optical D/A Converter for VLC Applications
Dobesch, Aleš ; Vlček, Čestmír (oponent) ; Vašinek, Vladimír (oponent) ; Wilfert, Otakar (vedoucí práce)
The dissertation deals with the optical digital to analog converter as an alternative transmitter front-end concept for visible light communication applications. The dissertation looks into optical channel modeling and suggests a suitable modeling approach. A significant part devoted to the numerical optical channel modeling reveals the influence of emitter bit depth, emitter array topology and geometrical arrangement on communication system performance. The dissertation deals with optical digital to analog converter design based on previously acquired simulations and explores overall front-end performance. Furthermore, the thesis presents a real time demonstration of high data rate optical communication using the front-end.
|
|
|
Spatial Identification Methods and Systems for RFID Tags
Povalač, Aleš ; Carvalho, Nuno Miguel Gonçalves Borges de (oponent) ; Polívka,, Milan (oponent) ; Šebesta, Jiří (vedoucí práce)
The doctoral thesis is focused on methods and systems for ranging and localization of RFID tags operating in the UHF band. It begins with a description of the state of the art in the field of RFID positioning with short extension to the area of modeling and prototyping of such systems. After a brief specification of dissertation objectives, the thesis overviews the theory of degenerate channel modeling for RFID communication. Details are given about phase-based ranging and direction of arrival finding methods. Several antenna placement scenarios are proposed for localization purposes. The degenerate channel models are simulated in MATLAB. A significant part of the thesis is devoted to software defined radio (SDR) concept and its adaptation for UHF RFID operation, as it has its specialties which make the usage of standard SDR test equipment very disputable. Transmit carrier leakage into receiver path and requirements on local oscillator signals for mixing are discussed. The development of three experimental prototypes is also presented there: experimental interrogator EXIN-1, measurement system based on Ettus USRP platform, and antenna switching matrix for an emulation of SIMO system. The final part is focused on testing and evaluation of described positioning techniques based on complex backscatter channel transfer function measurement. Both narrowband/wideband ranging and direction of arrival methods are validated. Finally, both proposed antenna placement scenarios are evaluated with real-world measurements.
|
|
|
An Optical D/A Converter for VLC Applications
Dobesch, Aleš ; Vlček, Čestmír (oponent) ; Vašinek, Vladimír (oponent) ; Wilfert, Otakar (vedoucí práce)
The dissertation deals with the optical digital to analog converter as an alternative transmitter front-end concept for visible light communication applications. The dissertation looks into optical channel modeling and suggests a suitable modeling approach. A significant part devoted to the numerical optical channel modeling reveals the influence of emitter bit depth, emitter array topology and geometrical arrangement on communication system performance. The dissertation deals with optical digital to analog converter design based on previously acquired simulations and explores overall front-end performance. Furthermore, the thesis presents a real time demonstration of high data rate optical communication using the front-end.
|
|
|
Spatial Identification Methods and Systems for RFID Tags
Povalač, Aleš ; Carvalho, Nuno Miguel Gonçalves Borges de (oponent) ; Polívka,, Milan (oponent) ; Šebesta, Jiří (vedoucí práce)
The doctoral thesis is focused on methods and systems for ranging and localization of RFID tags operating in the UHF band. It begins with a description of the state of the art in the field of RFID positioning with short extension to the area of modeling and prototyping of such systems. After a brief specification of dissertation objectives, the thesis overviews the theory of degenerate channel modeling for RFID communication. Details are given about phase-based ranging and direction of arrival finding methods. Several antenna placement scenarios are proposed for localization purposes. The degenerate channel models are simulated in MATLAB. A significant part of the thesis is devoted to software defined radio (SDR) concept and its adaptation for UHF RFID operation, as it has its specialties which make the usage of standard SDR test equipment very disputable. Transmit carrier leakage into receiver path and requirements on local oscillator signals for mixing are discussed. The development of three experimental prototypes is also presented there: experimental interrogator EXIN-1, measurement system based on Ettus USRP platform, and antenna switching matrix for an emulation of SIMO system. The final part is focused on testing and evaluation of described positioning techniques based on complex backscatter channel transfer function measurement. Both narrowband/wideband ranging and direction of arrival methods are validated. Finally, both proposed antenna placement scenarios are evaluated with real-world measurements.
|
host ::
RSS.