|
|
Fading channel hardware simulator
Pirochta, Pavel ; Kováč, Michal (referee) ; Maršálek, Roman (advisor)
Fading channel is a communication channel that experiences different interference and fading due to multi-path signal propagation. The fading channel is designed by the finite impulse response filter with the time-varying impulse characteristic. The realisation of this filtr is based on the TDL (Tapped Delay Line) model, which simulate signal delay and signal attenuation in each branch. The aim of this thesis is to create the VHDL design of selected fading channel simulator and its description for hardware implementation into the FPGA.
|
|
|
Simulation of multipah propagation of multistate modulations
Polák, Ladislav ; Pust, Radim (referee) ; Šebela, Radek (advisor)
The diploma thesis Simulation of Multipath Propagation of Multistate Modulations is focused on the development of an appropriate algorithm in MATLAB environment, which is capable to simulate the impact of the multipath propagation on received signal (error rate) on the basis of given parameters of the transmission channels. Mechanisms and characteristics of the wave propagation in communication environment, types of digital modulations and their most important parameters are described in the first part of this thesis. The second part is focused on the simulation itself. Created GUI (Graphical User Interface) is able to display constellation diagrams of transmitted and received signals, as well as their bit error rate. It is also possible to compare these data with the data of signal, which is passed by a non-fading channel.
|
|
|
Channel estimation in CDMA systems
Kadlec, Petr ; Prokopec, Jan (referee) ; Kejík, Petr (advisor)
The subject of this work deals with the problem of channel estimation for CDMA systems. This method of multiple access when individual users share the same full bandwidth simultaneously and are differentiated with any of pseudorandom sequences, is now the most perspective method. That is proved by its wide implementation in mobile networks of the third generation and higher systems. This work describes basic theory principles of spread spectrum, above all DS-CDMA (Direct Sequence-CDMA) and furthermore some phenomena of radio wireless channel that affect changes in transmitted signal in its way from transmitter to receiver. Terms of fading, multipath propagation, loss, refraction, scattering of the wave and Rice and Rayleigh probability density functions are mentioned. The third chapter deals with yet known and used capabilities of channel estimation. Differences, advantages and disadvantages of so-called blind estimation or training-based estimation are discussed. Two algorithms: LS method and sliding correlator are analyzed in more detail. There is also description of their simulations in Matlab and some results of these simulations are discussed. The last chapter deals with comparison of main characteristics and achievable accuracy of wireless channel impulse response estimation by both methods, and their possible utilization in real live.
|
|
|
Wireless transmission interference modeling (AWGN, Rayleigh, Rice fading channels)
Hloušek, Tomáš ; Gleissner, Filip (referee) ; Mikulka, Jan (advisor)
This thesis describes and models wirelesss transmission intereferences in real communication channels. A signal received on a fading channel is subjected to a multiplicative distortion and to the usual additive noise. Real channel adds to the signal noise and fadings. Gaussian noise is a result of channel awgn. Fadings is implicated by multipath propagation of signal in Rayleigh and Rician channels. Main goal of this project is to program BERsolve, which is created in tool GUIDE in Matlab. User program BERsolve makes it possible to analyse bit error rate and symbol error rate for some types of channel models, which are defined by standard COST207. BERsolve offers some other functions i.e. display time behaviour, constellation diagram and spectrum. This program provides us with an overview representation of problem by multipath interferences in communication channels.
|
|
| |
|
|
Adolescent speech of stress
TRNKOVÁ, Jana
The objective of this diploma thesis is to provide basic orientation in the topic of the adolescents stress and key concepts of this topic. The next objektive of the thesis is to compare the individual effects of Adolescents stress at grammar schools. Theoretical part of the thesis defins the basic terms - difficult life situation, stress, frustration, conflicts, escape, aggression, coping strategies, stress management programs and concepts related to adolescence - age groups, pubescence, adolescence, results of adolescents stress. Practical part of thesis defines the objectives and assumtions for evaluation, describes used method of evaluation, approximate research course and in the end verifies the assumptions.
|
|
|
The urgent and follow-up precautions in case release of ammonia - back analysis of past cases
CHOCOVÁ, Lenka
For this final paper, I chose a rather serious topic that is very topical in our society. Hazardous chemical substance ? ammonia ? is used very widely at present. Ammonia is used as a coolant in various plants. I have compiled a list of all plants in South Bohemia that work with ammonia, including ice rinks. I characterized the properties of ammonia, what damage it causes to the human organism and the environment. I noted a list of accidents during which there have been ammonia leakages of ammonia and I analyzed one accident using a software programme called TerEx. I chose the building of the ice rink in České Budějovice for my research. The objective was to determine the amount of ammonia and to simulate, using the TerEx software programme, an accident with a potential ammonia leakage from the ice rink. I also listed all the activities of the individual components of the Integrated Rescue System, which would help during such an accident, as well as urgent and follow-up measures that would be used. Having assessed the results I came to the conclusion that ammonia leakage from the ice rink would have serious impacts on the residents of České Budějovice. Finally I explained what the terms of evacuation and individual protection mean for the people lining around the ice rink.
|
|
|
Design of conception of data loss prevention
Brejla, Tomáš ; Střížová, Vlasta (advisor) ; Sejk, Vratislav (referee)
This work deals with the making of conception of implementation of processes and software tools designed to ensure sensitive data leakage prevention from the organization infrastructure. The structure consists of three key parts. The first one describes theoretical basis of the work. It explains what is the data loss prevention, what it comes from, why it is necessary to deal with it and what its goals are. It also describes how this fits into the whole area of corporate ICT security environment. There are defined all the risks associated with leakage of sensitive data and there are also defined possible solutions and problems that are associated with these solutions. The first part also analyzes the current state of data loss prevention in organizations. They are divided according to their size and for each group there is a list of the most common weaknesses and risks. It is evaluated how the organizations currently solve prevention of data loss and how they cover this issue from both a procedural point of view and in terms of software tools. The second part focuses directly on the software tools. It is characterized the principle of operation of these systems and it is explained their network architecture. There are described and evaluated current trends in the development of the data loss prevention tools and it is outlined possible further development. They are divided into different categories depending on what features they offer and how these categories cover the needs of organizations. At the end of the second part there are compared the software solutions from leading vendors in the market against actual experience, focusing on their strengths and weaknesses. The third part presents the core content. IT joins two previous sections and the result is the creation of the overall concept of the implementation of data loss prevention with focus on breakdown by several different levels -- processes, time and size of the company. At the beginning of this third section it is described what precedes the implementation of data loss prevention, and what the organizations should be careful of. It is defined by how and what the organizations should set their own expectations for the project could be manageable. The main point is the creation of a procedure of data loss prevention implementation by creating a strategy, choice of solutions, to the implementation of this solution and related processes. The end of the third part deals with the legal and personnel issues which are with the implementation of DLP very closely related. There are made recommendations based on analysis of the law standards and these recommendations are added to the framework approach of HR staff. At the very end there are named benefits of implementing data loss prevention, and the created concept is summarized as a list of best practices.
|
|
|
A simulated road accident of a tank truck in Ústí nad Labem resulting in chlorine leakage
LANGOVÁ, Regina
The main theme of the diploma thesis is simulated accident of a truck transporting pressure barrels with chlorine.The study is focused on evaluating the effects of the accident on the lives and health of the local population and assessing the risks (and the level of hazards) with the use of selected methods.In this study, the truck accident is described in detail and the risks are evaluated through using the IAEA-TECDOC-727 method, which is based on quantitative risk assessment of sources according to the level of hazard to lives.
|
|
| |
guest ::
