The Experts below are selected from a list of 80259 Experts worldwide ranked by ideXlab platform
Rastislav Roka - One of the best experts on this subject based on the ideXlab platform.
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Impact of Environmental Influences on Multilevel Modulation Formats at the Signal Transmission in the Optical Transmission Medium
2017Co-Authors: Rastislav Roka, Pavol ŠalíkAbstract:This paper is devoted to the analysis of environmental influences in the optical Transmission Medium and their impacts on multilevel modulation formats. An attention is focused on main features and characteristics of environmental negative influences of optical fibers. Consequently, principles for appropriate multilevel modulation formats are introduced together with block schemes representing their main functionalities. The created Simulink model for technologies and communications is verified for real conditions in the optical Transmission Medium. It can allow executing requested analysis for environmental influences on advanced multilevel modulation formats at the signal Transmission. Finally, a comparison of considered multilevel modulations is introduced, using constellation diagrams, signal characteristics, eye diagrams and waterfall curves of individual signals.
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Analyzing Influence of the Transmission Medium on Timing Signals Transmitted by Hybrid Optical Transport Technologies
International Journal of Advances in Telecommunications Electrotechnics Signals and Systems, 2017Co-Authors: Rastislav Roka, Veronika DolinayováAbstract:The contribution deals with synchronization aspects in SDH and Synchronous Ethernet timing networks utilizing optical Transmission Medium. First, it explains a hierarchical configuration of timing network elements, characterizes Transmission features of the optical fiber, particularly its main negative influences influencing transmitted information signals. The main part is dedicated to the evaluation program created for analyzing influences of the optical Transmission path on timing signals transmitted by SDH and SyncE transport technologies. At last, resultant values from the introduced evaluation program are presented and evaluated.
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Possibilities for Advanced Encoding Techniques at Signal Transmission in the Optical Transmission Medium
The Journal of Engineering, 2016Co-Authors: Filip Čertík, Rastislav RokaAbstract:This paper presents a possible simulation of negative effects in the optical Transmission Medium and an analysis for the utilization of different signal processing techniques at the optical signal Transmission. An attention is focused on the high data rate signal Transmission in the optical fiber influenced by linear and nonlinear environmental effects presented by the prepared simulation model. The analysis includes possible utilization of OOK, BPSK, DBPSK, BFSK, QPSK, DQPSK, 8PSK, and 16QAM modulation techniques together with RS, BCH, and LDPC encoding techniques for the signal Transmission in the optical fiber. Moreover, the prepared simulation model is compared with real optical Transmission systems. In the final part, a comparison of the selected modulation techniques with different encoding techniques and their implementation in real Transmission systems is shown.
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Modeling of the PSK utilization at the signal Transmission in the optical Transmission Medium
International Journal of Computer Network and Information Security, 2015Co-Authors: Rastislav Roka, Martin MokráňAbstract:This paper deals with a modeling of the phase shift keying (PSK) and the possibility of implementing PSK modulations using Mach-Zehnder modulators in the Matlab simulation environment. Next, a simulation of selected multi-level PSK modulations utilizing at the signal Transmission in the optical Transmission Medium is executed. Finally, a comparison of modulated optical signals before and after passing a model of the optical Transmission path is introduced, using constellation diagrams, signal characteristics, eye diagrams and waterfall curves of individual signals.
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SIMULTECH - Simulation and Analysis of the Signal Transmission in the Optical Transmission Medium
Proceedings of the 5th International Conference on Simulation and Modeling Methodologies Technologies and Applications, 2015Co-Authors: Rastislav Roka, Filip źertíkAbstract:This paper presents a possible way for simulating a signal Transmission in the optical Transmission Medium. A main attention is focused on characteristics and analysis of linear and nonlinear effects that influence optical signals transmitting in the environment of optical fibers. Simultaneously, functional blocks created in the Matlab Simulink programming environment for particular effects are presented in the proposed simulation model. At the same time, the paper present a simulation of the optical Transmission system that can include various modulation and encoding techniques utilized for the signal Transmission. In addition, a comparison of results from the proposed simulation model with measurements on real optical Transmission paths is introduced.
Hoi-jun Yoo - One of the best experts on this subject based on the ideXlab platform.
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The human body characteristics as a signal Transmission Medium for intrabody communication
IEEE Transactions on Microwave Theory and Techniques, 2007Co-Authors: Namjun Cho, Seonghyun Jeon, Seong Jun Song, Jeabin Lee, Jerald Yoo, Hoi-jun YooAbstract:The human body characteristics as a signal Transmission Medium are studied for the application to intrabody communication. The measurements of the body channel cover the frequency range from 100 kHz to 150 MHz and the distance on the body up to 1.2 m. A distributed RC model is developed to analyze the large variation of the channel properties according to the frequency and channel length. The simulation results using the channel model match well with the measurements in both the frequency and time domains. The effect of the ground plane to the body channel transceivers is also investigated and an empirical formula for the minimum ground size is obtained. Finally, the amount of the electromagnetic radiation due to the body antenna effect is measured. With regards to the Federal Communications Commission regulations, the proper frequency range for the intrabody communication is determined to satisfy given bit error rate requirements
Tetsushi Sekiguchi - One of the best experts on this subject based on the ideXlab platform.
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a very low power consumption wireless ecg monitoring system using body as a signal Transmission Medium
Sensors, 1997Co-Authors: T Handa, Shuichi Shoji, S Ike, S Takeda, Tetsushi SekiguchiAbstract:A very low-power consumption wireless system for monitoring ECG (electrocardiogram) is proposed. It consists of an ECG detector/transmitter located on the chest and the relay transmitter placed at the wrist. Between the detector part and the relay transmitter, the signal is send as the AC micro current flows through the tissue of the body. Since this method achieves very low-power signal Transmission of about 8 /spl mu/W (400 mV/sub RMS//spl times/20 /spl mu/A/sub RMS/), the system can be driven by a very small power source like a thin film battery. A similar wireless Transmission method can be applied for other medical signal/data sensing micro systems sharing the same relay transmitter.
Filip Čertík - One of the best experts on this subject based on the ideXlab platform.
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Possibilities for Advanced Encoding Techniques at Signal Transmission in the Optical Transmission Medium
The Journal of Engineering, 2016Co-Authors: Filip Čertík, Rastislav RokaAbstract:This paper presents a possible simulation of negative effects in the optical Transmission Medium and an analysis for the utilization of different signal processing techniques at the optical signal Transmission. An attention is focused on the high data rate signal Transmission in the optical fiber influenced by linear and nonlinear environmental effects presented by the prepared simulation model. The analysis includes possible utilization of OOK, BPSK, DBPSK, BFSK, QPSK, DQPSK, 8PSK, and 16QAM modulation techniques together with RS, BCH, and LDPC encoding techniques for the signal Transmission in the optical fiber. Moreover, the prepared simulation model is compared with real optical Transmission systems. In the final part, a comparison of the selected modulation techniques with different encoding techniques and their implementation in real Transmission systems is shown.
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Modeling of Environmental Influences at the Signal Transmission in the Optical Transmission Medium
International Journal of Computer Network and Information Security, 2012Co-Authors: Rastislav Roka, Filip ČertíkAbstract:This contribution discusses characteristics of environmental influences on transmitted signals in the optical Transmission Medium. A main attention is focused on the explanation of simulation methods for substantial linear and nonlinear negative effects in the optical fiber presented by the proposed simulation model. The paper also presents characteristics of modulation techniques utilized in the optical Transmission Medium. Finally, a comparison of different modulation techniques affected by various environmental influences in this simulation model is presented.
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Analysis of modulation techniques utilized in the optical Transmission Medium
2012 ELEKTRO, 2012Co-Authors: Filip Čertík, Rastislav RokaAbstract:This contribution deals with different types of modulation techniques and with characteristics of the optical environment. The paper presents a design and simulation of optical modulators when passing through an optical Transmission Medium with negative influences degrading the signal Transmission. Finally, the evaluation and comparison of these modulation methods are presented.
Namjun Cho - One of the best experts on this subject based on the ideXlab platform.
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The human body characteristics as a signal Transmission Medium for intrabody communication
IEEE Transactions on Microwave Theory and Techniques, 2007Co-Authors: Namjun Cho, Seonghyun Jeon, Seong Jun Song, Jeabin Lee, Jerald Yoo, Hoi-jun YooAbstract:The human body characteristics as a signal Transmission Medium are studied for the application to intrabody communication. The measurements of the body channel cover the frequency range from 100 kHz to 150 MHz and the distance on the body up to 1.2 m. A distributed RC model is developed to analyze the large variation of the channel properties according to the frequency and channel length. The simulation results using the channel model match well with the measurements in both the frequency and time domains. The effect of the ground plane to the body channel transceivers is also investigated and an empirical formula for the minimum ground size is obtained. Finally, the amount of the electromagnetic radiation due to the body antenna effect is measured. With regards to the Federal Communications Commission regulations, the proper frequency range for the intrabody communication is determined to satisfy given bit error rate requirements
