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Methods for quadrature modulator imbalance compensation
Povalač, Karel ; Valenta, Václav (referee) ; Maršálek, Roman (advisor)
Quadrature modulator (demodulator) is used in transmitting (receiving) part of many devices. Unwanted imbalance can influence amplitude, phase or DC offset of modulator (demodulator). Correction of imbalance was a main subject of thesis. Simulations of these methods were created in MATLAB and results were compared. Basics of methods were implement on programmable logic field by program Xilinx ISE. Development kit V2MB1000 with analogue board Memec P160 was chosen for this purpose. In the last part were compare simulation results with practical measurement.
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Telecommunication Education Environment and its Optimal Usage
Al Salman, Ahmed Nasser M ; Vychodil, Petr (referee) ; Škorpil, Vladislav (advisor)
Students in introductory communication theory classes can benefit from a well-planned laboratory component. Such that TIMS lap equipments which can handle a wide variety of experiments ranging from analog baseband to pass-band digital communications. These papers describe three advanced laboratory tasks with their optimized manuals designed by Al Salman Ahmed at Brno University of technology. Two are based on the simulation software TutorTIMS to implement Eye patterns, Signal Constellations, and the third is based on the Biskit hardware to implement Quadrature phase shift keying (QPSK).
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Signal Processing in Flarion System
Szajkó, Juraj ; Kejík, Petr (referee) ; Hanus, Stanislav (advisor)
Cílem bakalářské práce Zpracování signálů v systému Flarion bylo prostudovat způsoby zpracování signálu ve fyzické vrstvě a architekturu sítě Flarion. Na základě získaných poznatků při studiu fyzické vrstvy bylo za úkolem sestavit v prostředí Matlab model systému a simulace BER v závislosti na poměr vysílaného výkonu a výkonu rušivého signálu. V první části práce je detailní popis fyzické vrstvy Flarionu, probrána je baseband a OFDM modulace, LDPC kódování a frekvenční skákání. V druhém části práce je prostudována architektura sítě, ekvalizace, řízení výkonu, radiových zdrojů, a způsob handoffu. Ve třetí části práce je vytvoření downlink a uplink modelu v Matlab, dále je provedena simulace BER v závislosti na poměr vysílaného výkonu a výkonu rušivého signálu.
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Analysis of Converged Networks by Simulations
Gardáš, Vít ; Novotný, Bohumil (referee) ; Škorpil, Vladislav (advisor)
The primary purpose of this study is to analyze converged high-speed networks with the usage of Matlab and Simuling. To set problematic area in the field of high-speed networks and solve this problem by creating a model of measurement and simulation of this model. A laboratory exercise is afterwards created on the specific problem.
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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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DOCSIS Technology in Access Networks
Pirohanič, Lukáš ; Šilhavý, Pavel (referee) ; Horváth, Tomáš (advisor)
This bachelor thesis explains the design and implementation of data communication between a central unit and a cable modem. Suitable transfer medium and intermediate devices for signal forking and amplification are chosen in practical part of the work. The upstream and downstream channel transfer rates are tested using modulation techniques and also testing the DOCSIS Network for qualitative parameters and laboratory task dealing with the DOCSIS standard. The theoretical part describes DOCSIS standard, CATV network architecture and signal modulation during transmission.
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Modelling of Power Line Communication for data transmission
Kadlček, Václav ; Mišurec, Jiří (referee) ; Mlýnek, Petr (advisor)
Thesis deals with problems PLC (Power Line Communication) communication. It is aimed at drawing up a suitable model for testing power network PLC communication. The reader is aware of at the beginning of work with the basic principles of PLC systems, distribution and use in communication networks. Another part of the work deals with different types of interference, which occur in power networks and ways to defend against such interference. For example, an appropriate choice of modulation and coding relevant. As a source of interference in the proposed model is used AWGN channel (Additive White Gaussian Noise). Conclusion of work is dedicated to design and build a model for PLC communication. There are three models designed with different OFDM technology. Models therefore vary between different levels of key mapping in OFDM (QPSK, 16-QAM, 64-QAM). It made a detailed description of a set of blocks that were used to build models. The behavior and functionality of the proposed models for broadband PLC communication was verified in the simulation program Matlab Simulink. Finally, it is shown the comparison and evaluation of results of each modulation.
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Implementation of software radio into FPGA
Šrámek, Petr ; Maršálek, Roman (referee) ; Prokeš, Aleš (advisor)
The common objective of this project is implementation of software defined radio (SDR) into FPGA. The text contains review and comparison of several hardware concepts intended for SDRs implementation then the methods for digital implementation of various components of radios as the filters, mixers and others are mentioned. Part of the text introduces used hardware platform and describes software support for designing, simulations and implementation into hardware. Significant part of project describes complex of external hardware components as filter, amplifier and control panel designed and built within the project realization. But the main part of project demonstrates design of the software solution of radio receiver. There is specified architecture of radio for FM broadcast receiving, next the more complex systems with carrier recovery algorithm are presented. These systems are able to work with AM, BPSK and QPSK modulations. It is possible to implement all these receivers into hardware and verify their operation. The practical laboratory theme has been outlined within the project run.
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Modulator and demodulator for microwave link
Martinec, Matěj ; Frydrych, Jiří (referee) ; Záplata, Filip (advisor)
This work is dealing with the design of intermediate part of transmitter and reciever that use digital BPSK and QPSK modulations for microwave link that works in 24 – 26 GHz bands. Besides choosing the suitable modulator and demodulator there was need to provide proper connection of this part with transceiver Nortel CTR26-01M. Input and output of this intermediate part was take out to baseband, where was need to ensure the transfer of diferential inputs of modulator and demodulator to symetric leading for reason of data communication with PC, for which was created the algorithms to provide transmitting and receiving data. Complete structure controlled by the microcontroller has been enliven and furthemore there was created the measurement of chosen parameteres.
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