Search for dissertations about: "load modulation"

Showing result 11 - 15 of 55 swedish dissertations containing the words load modulation.

  2. 11. Multirate Codes and Multicarrier Modulation for Future Communication Systems

    Author : Pål Frenger; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; channel estimation; code-spread CDMA; DS-CDMA; convolutional codes; interference cancellation; nested convolutional codes; multicarrier modulation; optimum distance spectrum ODS ; rate-compatible punctured convolutional codes RCPC-codes ; OFDM; turbo decoding; rate matching; parallel combinatory signaling; Rayleigh fading;

    Abstract : In this thesis, new detection and modulation methods for multicarrier systems are presented. The proposed multicarrier detectors are based on feedback of previously detected symbols and the idea is to exploit the correlation, both in time between consecutive symbols, and in frequency between neighboring sub-carriers. READ MORE

  4. 12. Power System Oscillations - Detection, Estimation and Control

    Author : Morten Hemmingsson; Industriell elektroteknik och automation; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Elektroteknik; oscillation; power system; damping; power swing; distance protection; detection; estimation; real-time; reactive co-variation; control; Electrical engineering; load modulation; Automation; robotics; control engineering; Automatiska system; robotteknik; reglerteknik;

    Abstract : The topic of this thesis is the electro-mechanical oscillations which to some extent always are present in a power system. The demand of electric power is ever increasing. At the same time, the tolerance of disruptions in the power supply is decreasing. READ MORE

  5. 13. Theory and Design of Efficient Active Load Modulation Power Amplifiers

    Author : Han Zhou; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; GaN; circulator; non-reciprocity; Doherty power amplifier; Combiner synthesis; CLMA; deep power back-off; energy efficiency;

    Abstract : The increasing demand for mobile data traffic has put new challenges and requirements for the development of the wireless communication infrastructure. The performance of the RF power amplifier (PA) is, in particular, of great importance, since it is the key building block for microwave transmitters in base stations and radio link equipment. READ MORE

  6. 14. On soft-switching isolated AC/DC converters without auxiliary circuit

    Author : Staffan Norrga; Stefan Östlund; Rik De Doncker; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical power technology; voltage source converter; cycloconverter; isolated converter; medium frequency transformer; soft switching; modulation; commutation; wind power; electric traction; Elkraftteknik; Electric power engineering; Elkraftteknik;

    Abstract : The thesis is concerned with a class of power electronic converter systems that permit bidirectional AC/DC conversion with galvanic separation of the AC and DC sides by a transformer operating at elevated frequency. The systems consist of a capacitively snubbered voltage source converter and a cycloconverter, separated by the mentioned transformer. READ MORE

  7. 15. System Aspects and Modulation Strategies of an HVDC-based Converter System for Wind Farms

    Author : Stephan Meier; Hans-Peter Nee; Boon-Teck Ooi; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Isolated AC DC Converter; Mutual Commutation; Soft Switching; Voltage Source Converter; Cycloconverter; Modulation Strategies; Medium-Frequency Transformer; HVDC Transmission; Wind Power; Wind Farms; Electric power engineering; Elkraftteknik; Electrical engineering; Elektroteknik;

    Abstract :   In this thesis, a new HVDC-based converter system for wind farms is investigated. It is based on a mutually commutated soft-switching converter system and provides a unique integrated solution for the wind turbine generator drive systems, the wind turbine interconnection, and the power conversion for HVDC transmission. READ MORE