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Equalization Methods in Digital Communication Systems
Deyneka, Alexander ; Šilhavý, Pavel (referee) ; Číž, Radim (advisor)
Tato práce je psaná v angličtině a je zaměřená na problematiku ekvalizace v digitálních komunikačních systémech. Teoretická část zahrnuje stručné pozorování různých způsobů návrhu ekvalizérů. Praktická část se zabývá implementací nejčastěji používaných ekvalizérů a s jejich adaptačními algoritmy. Cílem praktické části je porovnat jejich charakteristiky a odhalit činitele, které ovlivňují kvalitu ekvalizace. V rámci problematiky ekvalizace jsou prozkoumány tři typy ekvalizérů. Lineární ekvalizér, ekvalizér se zpětnou vazbou a ML (Maximum likelihood) ekvalizér. Každý ekvalizér byl testován na modelu, který simuloval reálnou přenosovou soustavu s komplexním zkreslením, která je složena z útlumu, mezisymbolové interference a aditivního šumu. Na základě implenentace byli určeny charakteristiky ekvalizérů a stanoveno že optimální výkon má ML ekvalizér. Adaptační algoritmy hrají významnou roli ve výkonnosti všech zmíněných ekvalizérů. V práci je nastudována skupina stochastických algoritmů jako algoritmus nejmenších čtverců(LMS), Normalizovaný LMS, Variable step-size LMS a algoritmus RLS jako zástupce deterministického přístupu. Bylo zjištěno, že RLS konverguje mnohem rychleji, než algoritmy založené na LMS. Byly nastudovány činitele, které ovlivnili výkon popisovaných algoritmů. Jedním z důležitých činitelů, který ovlivňuje rychlost konvergence a stabilitu algoritmů LMS je parametr velikosti kroku. Dalším velmi důležitým faktorem je výběr trénovací sekvence. Bylo zjištěno, že velkou nevýhodou algoritmů založených na LMS v porovnání s RLS algoritmy je, že kvalita ekvalizace je velmi závislá na spektrální výkonové hustotě a a trénovací sekvenci.
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Gateway for monitoring maritime transport
Fučík, Stanislav ; Číž, Radim (referee) ; Musil, Petr (advisor)
This thesis addressed the monitoring of maritime traffic. The aim was to evaluate current solutions in the field of maritime traffic monitoring and to design and create new solution. The proposed solution is powered by solar panels and Li-Ion batteries. For sending data, satellite and mobile connections is be used. As a source of information about position GPS is used. The monitoring unit is equipped with sensors for measuring temperature, humidity, acceleration, intrusion of into the container and a detector of the opening door. The unit is resistant to the atmospheric influences prevailing sea and is operational long-term at sea.
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Analyzer of IEEE 802.15.4 radio channels
Pokorný, Jiří ; Číž, Radim (referee) ; Šimek, Milan (advisor)
The master’s thesis deals with development of the radio channel analyser operating in the unlicensed 2.4 GHz band according to IEEE 802.15.4 standard. The analyzer will contain two basic functions, namely energy detection of channels and analysation of selected channel. Detection of energy will be solved by selection between simple graph and text list on display. Based on information about the occupancy of channels the user can decide which channel would be set up. During the receiving of valid frame the source address, signal strength and signal quality will be stored. At the end the processor will show these data on display. For controlling the device will be installed two LEDs and four buttons.
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Heart Rate Variability Measurement Device
Süss, Ivo ; Číž, Radim (referee) ; Strašil, Ivo (advisor)
The aim of this thesis was to develop a device that will receive the signal from sporttester belt and then that signal will be processed. The meter is based on development kit STM32 Primer 2. To receive signals from sporttester belts uses sensor RMCM-01 Polar. The meter allows measurement of parameters of heart variability, recording on a memory card and work with the measured data from the memory card.
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Automatic counting of people
Mitáček, Štěpán ; Číž, Radim (referee) ; Koutný, Martin (advisor)
This effort deals with the problem of effective counting of people in the room. Although more companies deal with this problem at present, but their systems are very expensive. For this reason I strive to find a cheaper solution for counting people using active infra- red sensors by which I want to perceive the passage of a person through the door or his presence in the room. In addition it is necessary to take into consideration the other various situations that may occur when a person comes into the room or when he/she leaves. These situations can be in many cases similar, but the output should be able correctly distinguish the possibilites. The result of this effort is detector which is able to detect correctly one person or more people passing the door. People can browse through a door one behind the other, but they also can pass in the doorway in random combinations.
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Laboratory exercises making use of the industrial sensor system ADAM
Mixa, Jan ; Číž, Radim (referee) ; Rampl, Ivan (advisor)
The main Objective of the Bachelor Thesis is to familiarize with industry sensor system. The whole system is based on Modules ADAM 4000, RS 485 Bus, a Personal Computer with RS 232 Bus. It is important to understand how the system works and what method of communication is between system components. For this Purpose are designed two laboratory tasks. The first task is „Thermal quantity sensor“, for this task is used a development environment designed directly for ADAM modules – ADAMview. The second task is called „ADAM ASCII protocol“. Sensor System with ADAM modules provides simplicity, comfort and precision of measurements.
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Open Source IMS implementations
Ježek, Jiří ; Číž, Radim (referee) ; Šilhavý, Pavel (advisor)
The diploma thesis deals with open source implementations of IMS technology. The theoretical part describes the functioning of IMS and its architecture, including the protocols used, the process of registration and connection establishment, as well as potential security threats to IMS systems. Two open source IMS projects were selected, Open IMS Core and Project Clearwater, on which the work is focused. In its next part, the diploma thesis deals with the description of selected open source IMS projects, this part also includes a description of the implemented security of both projects and a detailed procedure of system installation with any necessary configuration. In its practical part, the diploma thesis focused on performance testing of selected projects using the Abacus 5000 hardware tester. First, initialization tests were performed, which verified the possibility of communication between the tester and the tested projects. Subsequently, it was possible to perform performance testing of selected projects. In performance testing, emphasis is placed on system stability, performance in the area of call set-up speed and response time of SIP messages and speed of user registration in the network, at different load levels. The systems have been tested for both call set-up and user registration. Part of the testing is also the implementation of the flood DoS inviteflood attack and the system's response to the increasing intensity of the attack. The last chapter is devoted to the comparison of selected IMS projects, where the test results are clearly presented. This chapter is partly based on publicly available information, such as the technical documentation of individual projects and possibly publicly available mailing lists. Part of the diploma thesis is also a laboratory task in which the student tries to work with Open IMS Core. The laboratory task focuses on the process of creating a user and his registration in the IMS network, establishing a call between individual users and internal routing in IMS networks. The task focuses mainly on signaling processes within the implemented tasks.
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G.fast transmission technology
Zvařič, Filip ; Číž, Radim (referee) ; Šilhavý, Pavel (advisor)
This diploma thesis focuses on G.fast and VDSL2 technologies and their comparison. G.fast has the prerequisites for replacing VDSL2 for short distances. This work describes in detail the modulation techniques of both DSL technologies - DMT modulation used by both technologies. The aim of this work is to create a software for comparing the transfer rates of all profiles of both technologies, including the effects of far-end crosstalk. This is performed in the Matlab environment. This work describes how the program works and how to run the simulations. The results of selected simulations and their charts are enclosed in this work.
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Model of transmission channel for xDSL systems
Jedlička, Zdeněk ; Číž, Radim (referee) ; Krajsa, Ondřej (advisor)
This bachelor thesis introduces the xDSL systems, shows the distribution of group members to symmetric and asymmetric, and shows the possibility of modeling the transmission channel for xDSL systems. It also gives ways you can get primary and secondary cable parameters and shows the potential of simulation. These parameters are used to calculate the transfer function, embedded input impedance and attenuation using the program, which is an integral part of this work.
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