This work deals with possibilities of operating signals under the power supply voltage and using of this technology in guidance of a model of railway. Firstly there is an analysis of analogous and digital guidance of the model of railway. There is also a description of theory of three kinds of used modulations such as ASK, FSK and OFDM modulation. There are described only principles of those modulations because the problematic of the modulation is going to be solved by integrated circuit. The next part of this work is going to deal with a market research and with description integrated circuits, which ensure the modulation of operating signals of power supply voltage. There is also going to be noticed a description of others circuits that are needed for the correct function of the whole furnishing. Then I will continue with a project of scheme and single PCB for a guidance of the model of the railway. The last part of this work is concerned with activation and a proof of those proposed linkage.

The thesis focuses on consideration of possible ways how to realize multi-state modulators for a laboratory instrument. This instrument will illustrate signals, which partake on generation QAM modulation. The design of the laboratory instrument includes theoretic schemata and the execution of a prototype. There are theoretical facts of multi-state signals and multi-state modulations in this thesis. A simple block diagram of the laboratory instrument is made by the theory of creating quadrature amplitude modulation. For each block there are made several schemata, which are compiled to the global scheme. A printed circuit board and the structure items are made by the aid of the global scheme. The next part is devoted to a software facility for a used microprocessor, which ensures the whole function of the laboratory instrument. The final section deals with measuring, which checks the function of the modulator and the right setting coder’s constellation diagrams.

The intended goal within the scope of this master´s thesis is to get acquainted with the product of EMONA INSTRUMENTS Company. There are two main concepts: the software version TutorTIMS – Advanced and the hardware version TIMS-301. Both concepts were bought into the laboratory, where the following subjects are being lectured: “Access and transport networks” and “Telecommunication network services”. Three laboratory exercises were prepared for both software version and hardware version. Both versions are modular and all designed exercises support independent and creative approach of students. All exercises also consist of standard parts, which are the description of the exercise and exemplary protocol solution. The first exercise is called “amplitude modulation” and is designed as an introductory exercise. Next are a couple of exercises which are designed to be performed on one workplace at the same time. The first of them is focused on practical verification of facts from amplitude shift keying, the second one focuses on link codes. This couple of exercises is the best choice, considering the hardware version of TIMS-301 and at the present time available modules in the lab. Software version is not limited in such way, but it was required to allow performing all of prepared exercises on both versions. Lastly there is a comparison between the software and hardware version and several options for hardware TIMS optimization.

Diploma thesis is focused on principles of measuring the vibrations using accelerometers and using them for making vibration measuring instrument with focus on modern integrated digital accelerometers. In the first part are described ways to measure acceleration and vibrations with available technical supplies with respecting place and purpose of measuring. In practical part are measured characteristics of used sensor, instrument for measuring vibrations is designed and built and for few experimental object vibrations or acceleration are measured and graphical interpreted.

The goal of the theses is to propose an idea for a generator of a radar polyphase modulated signal, that will operate at a frequency of 30 MHz. At the beginning of this project, an outline of the basic structure of the generator is proposed and a function of a programable logical perimeter is analyzed. This perimeter, together with an oscillator, generate two mutually phase-shifted rectangular pulses in its outputs. The shift phase of these two pulses is set by a program, and operated by single-chip processor. Those pulses are consequently converted to sinusoidal wave with the help of filters, and the required phase is chosen by the multiplexer, which is also operated by the processor. The phase modulation is realized this way. The output signal of the generator is radiopulse, which subpulses are phase modulated by the described method. Individual parts are solved analogously in this Theses.

Master’s thesis deals with possibilities of data communication on low voltage power lines, so-called PLC. This technology allows data transfer on power lines. According frequency band the PLC can be subdivide into narrowband or broadband class. Given are theoretical knowledge’s of data communication on power lines and describes technical solutions. Consequently is suggestion of LAN, which is accessible for commercial usage made by DS2 and his suitable for home use. The main acquisition is implementing and measuring this experimentally created LAN in family house. The results are real bitrates depending on distance and quality of specific connection.

The objective of Diploma thesis is design of analysis tool for equalizers used in FMT modulation. The model of transmission channel was designed for simulations with FMT. The transmission path is modeled by test loop, which corresponds to DSL line. For this reason, some principles of DSL technology is described in the thesis. The principles of multicarrier modulation are introduced in first part. The multicarrier modulation with filter bank (FMT) is described in detail.The different methods of design the fiter bank are given and compared. Channel equalization are introduced in second part. The attention was focused on minimum mean square error filtering (MMSE). Decision feedback channel equalizer (DFE) is extended from linear MMSE equalizer. DFE equalizers were programmed in analysis tool. For computation of equalizer coeficients was used also equalizers based on adaptive algorithms and MMSE. The last part describes the results of DFE equalizers used in communication system with FMT modulation. Analysis tool was programmed in MATLAB with a graphical user interface. It allows to show mean square error, signal-to-noise ratio and transmission speed dependence on delay between original and distorted signal. Signal-to-noise ration is displayed also in individual subchannels and users can display mean square error dependence on different orders of DFE filters.

The purpose of this paper is to study the possibilities of the OFDM system adaptive modulation. The study presents mechanism for acquiring the necessary data of every frequency subchannel using pilot signals and application of these data for system adjustment. The paper introduces the water-filling principle for subchannel power allocation on the basis of their SNR and adaptive modulation mechanisms for variety of OFDM usage. These mechanisms are implemented into a MATLAB model. The code is then transformed into graphical representation and using USRP2, the signal is transmitted by real world channel.

This project deals with transistorized converters in particular a four-quadrant bridge. The main part of project discusses the drivers of transistors and a possible way of controlling a converter. The proposal of control electronics and the regulation structure are involved in the second part. This project also includes a construction of an apparatus which will be used as a teaching material.

The object of this work is to meet readers with the basic principle and solution of high order digital modulator with integrated circuit AD9957 produced by the company Analog Devices. Block diagram and final scheme of the modulator and device construction is presented. Standard USB interface for communication, control and data transmission between modulator and host represented by personal computer is applied. The project describes following parts of the designed system: PCB layout, control firmware of MCU and application program running under PC. In the conclusion, chosen results of measurement are described and evaluated.