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Modulations in PLC systems
Procházka, Vít ; Kouřil, Jiří (referee) ; Krajsa, Ondřej (advisor)
The bachelor thesis describes principles and methods of Powerline Communications, practical usage possibilities both in industrial applications but mainly in broadband systems that may represent promising competition to conventional broadband access, e. g. xDSL connections without the need of new wiring, WIFI etc. The thesis also focuses on problems that can occur in the communication channel from the view of electromagnetic compatibility and assorted interferences. The 50 Hz frequency electric network (60 Hz in the USA) was not designed for data signal transmission, problems may arise mainly at higher frequencies and broadband communication. It is necessary to implement methods which enable transfer of information signal through a communication channel with minimalization of problems such as interference, cable attenuation, electromagnetic compatibility, bit error rate (BER), etc. Furthermore, currently used modulation principles and their characteristics are described, such as spread spectrum modulation DSSS, FHSS, traditional OFDM, alternative modulations FMT and DWMT with filter banks. The last chapter of the bachelor thesis features models of particular modulations created in the Matlab-Simulink program and the conclusion presents advantages and disadvantages of their implementation in PLC systems.
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Minimizing the effect of interference on wireless network
Doležal, Jan ; Kyselák, Martin (referee) ; Škorpil, Vladislav (advisor)
This thesis is concerned the technology with technologies of transfer through wireless devices. It is about possibilities of optimization of transfer in wireless net, especially of the reduction of interference influence. The first part is about theory and the standards development of wireless technology. There are methods and principles used in wireless technologies. The second part is a practical measuring and testing of an internal wireless net, with the emphasis being on the source of interference influence. Measuring was focused on interference between access points and was not about meteorological influence. It continues with theory and testing of interference of the microwave oven in our wireless net. Then, it is a practical demonstration of interference in an external environment. There are practical examples of interference between different providers’ nets on the same area and solutions to prevent or to cancel this interference. In next part of work the wireless net is parsed and described in a given territory. Here is described the way how to precede the reciprocal interference and eventually how this mutual disturbance suppress. Consequently, our net is optimized for customer growth and for today’s options of newer and more powerful components for wireless transfer. Finally there are two laboratory tasks. The first one is about practical measuring and testing of wireless net’s parameters and the second one is about simulation of wireless networks in the Opnet program.
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Modulations in PLC systems
Procházka, Vít ; Kouřil, Jiří (referee) ; Krajsa, Ondřej (advisor)
The bachelor thesis describes principles and methods of Powerline Communications, practical usage possibilities both in industrial applications but mainly in broadband systems that may represent promising competition to conventional broadband access, e. g. xDSL connections without the need of new wiring, WIFI etc. The thesis also focuses on problems that can occur in the communication channel from the view of electromagnetic compatibility and assorted interferences. The 50 Hz frequency electric network (60 Hz in the USA) was not designed for data signal transmission, problems may arise mainly at higher frequencies and broadband communication. It is necessary to implement methods which enable transfer of information signal through a communication channel with minimalization of problems such as interference, cable attenuation, electromagnetic compatibility, bit error rate (BER), etc. Furthermore, currently used modulation principles and their characteristics are described, such as spread spectrum modulation DSSS, FHSS, traditional OFDM, alternative modulations FMT and DWMT with filter banks. The last chapter of the bachelor thesis features models of particular modulations created in the Matlab-Simulink program and the conclusion presents advantages and disadvantages of their implementation in PLC systems.
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|
|
Minimizing the effect of interference on wireless network
Doležal, Jan ; Kyselák, Martin (referee) ; Škorpil, Vladislav (advisor)
This thesis is concerned the technology with technologies of transfer through wireless devices. It is about possibilities of optimization of transfer in wireless net, especially of the reduction of interference influence. The first part is about theory and the standards development of wireless technology. There are methods and principles used in wireless technologies. The second part is a practical measuring and testing of an internal wireless net, with the emphasis being on the source of interference influence. Measuring was focused on interference between access points and was not about meteorological influence. It continues with theory and testing of interference of the microwave oven in our wireless net. Then, it is a practical demonstration of interference in an external environment. There are practical examples of interference between different providers’ nets on the same area and solutions to prevent or to cancel this interference. In next part of work the wireless net is parsed and described in a given territory. Here is described the way how to precede the reciprocal interference and eventually how this mutual disturbance suppress. Consequently, our net is optimized for customer growth and for today’s options of newer and more powerful components for wireless transfer. Finally there are two laboratory tasks. The first one is about practical measuring and testing of wireless net’s parameters and the second one is about simulation of wireless networks in the Opnet program.
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