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Model of physical layer of communication system IEEE 802.11ah
Jurák, Petr ; Staněk, Miroslav (referee) ; Polák, Ladislav (advisor)
This diploma thesis deals with the analysis of the IEEE 802.11ah wireless communication system. For such a purpose, an appropriate simulation model in program environment MATLAB is created. The first part of thesis focuses on the IEEE 802.11 standard. Basic blocks of the transmitter and receiver are described. Attention is also devoted on the brief description of considered transmission channels. The second part contains the description of the proposed and realized simulation model in MATLAB. Individual blocks of the simulation model are described in details. Finally, the obtained simulation results are evaluated and discussed.
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COMMUNICATION CHAIN SUB-BLOCK MODELLING AND IMPLEMENTATION IN FPGA
Kubíček, Michal ; Jalovecký, Rudolf (referee) ; Pinker,, Jiří (referee) ; Kolka, Zdeněk (advisor)
Most modern clock and data recovery circuits (CDR) are based on analog blocks that need to be redesigned whenever the technology process is to be changed. On the other hand, CDR based blind oversampling architecture (BO-CDR) can be completely designed in a digital process which makes its migration very simple. The main disadvantages of the BO-CDR that are usually mentioned in a literature are complexity of its digital circuitry and finite phase resolution resulting in larger jitter sensitivity and higher error rate. This thesis will show that those problems can be solved by designing a new algorithm of BO-CDR and subsequent optimization. For this task an FPGA was selected as simulation and verification platform. This enables to change parameters of the optimized circuit in real time while measuring on real links (unlike a simulation using inaccurate link models). The output of this optimization is a new BO-CDR algorithm with heavily reduced complexity and very low error rate. A new FPGA-based method of jitter measurement was developed (primary for CDR analysis), which enables a quick link characterization without using probing or additional equipment. The new method requires only a minimum usage of FPGA resources. Finally, new measurement equipment was developed to measure bit error distribution on FSO links to be able to develop a suitable error correction scheme based on ARQ protocol.
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Simulation of the RF Transmission Channel for the DVB-H and DVB-SH
Hrach, Petr ; Fliegel, Karel (referee) ; Polák, Ladislav (advisor)
Project is focused on description DVB broadcasting for hand-held’s. It describes standard DVB-H that is founded on DVB-T and uses its transmission infrastructure. Standard DVB-SH is a hybrid system that adds to terrestrial broadcasting satellite connection. Signal can extend by various environments, therefore it are defined models transmission channel with defined parameters. Simulation of the transmission in both channel are realized in user application created in MATLAB. Finally, obtained results are evaluated and discussed.
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Measurement of DVB-T transmission over simulated fading channel
Vašut, Jakub ; Kratochvíl, Tomáš (referee) ; Štukavec, Radim (advisor)
The goal of this bachelor’s thesis is to study basic functional elements of coder and modulator of standart DVB-T. Another goal is to study documentation of DVB-T modulator DTA-110T and ASI/SDI adapter DTA-145 by DekTec. Also is described software channel simulator DTC-305 and parameter settings of simulated fading channel. Fading channels are measured and assigned their effect on quality of received DVB-T signal.
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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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Model of physical layer of communication system IEEE 802.11ah
Jurák, Petr ; Staněk, Miroslav (referee) ; Polák, Ladislav (advisor)
This diploma thesis deals with the analysis of the IEEE 802.11ah wireless communication system. For such a purpose, an appropriate simulation model in program environment MATLAB is created. The first part of thesis focuses on the IEEE 802.11 standard. Basic blocks of the transmitter and receiver are described. Attention is also devoted on the brief description of considered transmission channels. The second part contains the description of the proposed and realized simulation model in MATLAB. Individual blocks of the simulation model are described in details. Finally, the obtained simulation results are evaluated and discussed.
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Measurement of DVB-T transmission over simulated fading channel
Vašut, Jakub ; Kratochvíl, Tomáš (referee) ; Štukavec, Radim (advisor)
The goal of this bachelor’s thesis is to study basic functional elements of coder and modulator of standart DVB-T. Another goal is to study documentation of DVB-T modulator DTA-110T and ASI/SDI adapter DTA-145 by DekTec. Also is described software channel simulator DTC-305 and parameter settings of simulated fading channel. Fading channels are measured and assigned their effect on quality of received DVB-T signal.
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COMMUNICATION CHAIN SUB-BLOCK MODELLING AND IMPLEMENTATION IN FPGA
Kubíček, Michal ; Jalovecký, Rudolf (referee) ; Pinker,, Jiří (referee) ; Kolka, Zdeněk (advisor)
Most modern clock and data recovery circuits (CDR) are based on analog blocks that need to be redesigned whenever the technology process is to be changed. On the other hand, CDR based blind oversampling architecture (BO-CDR) can be completely designed in a digital process which makes its migration very simple. The main disadvantages of the BO-CDR that are usually mentioned in a literature are complexity of its digital circuitry and finite phase resolution resulting in larger jitter sensitivity and higher error rate. This thesis will show that those problems can be solved by designing a new algorithm of BO-CDR and subsequent optimization. For this task an FPGA was selected as simulation and verification platform. This enables to change parameters of the optimized circuit in real time while measuring on real links (unlike a simulation using inaccurate link models). The output of this optimization is a new BO-CDR algorithm with heavily reduced complexity and very low error rate. A new FPGA-based method of jitter measurement was developed (primary for CDR analysis), which enables a quick link characterization without using probing or additional equipment. The new method requires only a minimum usage of FPGA resources. Finally, new measurement equipment was developed to measure bit error distribution on FSO links to be able to develop a suitable error correction scheme based on ARQ protocol.
|
|
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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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Simulation of the RF Transmission Channel for the DVB-H and DVB-SH
Hrach, Petr ; Fliegel, Karel (referee) ; Polák, Ladislav (advisor)
Project is focused on description DVB broadcasting for hand-held’s. It describes standard DVB-H that is founded on DVB-T and uses its transmission infrastructure. Standard DVB-SH is a hybrid system that adds to terrestrial broadcasting satellite connection. Signal can extend by various environments, therefore it are defined models transmission channel with defined parameters. Simulation of the transmission in both channel are realized in user application created in MATLAB. Finally, obtained results are evaluated and discussed.
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