Search for dissertations about: "direct modulation"

Showing result 1 - 5 of 161 swedish dissertations containing the words direct modulation.

  2. 1. Modulation of Modular Multilevel Converters for HVDC Transmission

    Author : Arman Hassanpoor; Hans-Peter Nee; Staffan Norrga; Rainer Marquardt; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC; switching schemes; modulation; high power converters; power grids; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The outstanding features of modular multilevel converters (MMC) have recently gained much attention in the high-voltage direct-current (HVDC) transmission field. Power quality, converter cost and system performance are three crucial aspects of HVDC MMCs which are directly linked to the converter modulation and switching schemes. READ MORE

  4. 2. Unveiling the nature of dark matter with direct detection experiments

    Author : Vanessa Zema; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NaI; phenomenology; annual-modulation; direct-detection; cryogenics; COSINUS; polarised-nuclei; CRESST; dark-matter; phonons;

    Abstract : The desire of discovery is an anthropic need which characterises and connects the human being over the eras. In particular, observing the sky is an instinctive drive exerted by the curiosity of the mysteries which it retains. READ MORE

  5. 3. Low Noise Oscillator in ADPLL toward Direct-to-RF All-digital Polar Transmitter

    Author : Jian Chen; Li-Rong Zheng; Fredrik Jonsson; Hannu Tenhunen; Georges Gielen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; all-digital; digitally-intensive; frequency modualtion; phase modulation; amplitude modulation; polar; transmitter; oscillator; digital controled oscillator; DCO; VCO; voltage controled oscillator; class-C oscillator; class-D PA; ADPLL; phase noise; RF; CMOS.;

    Abstract : In recent years all-digital or digitally-intensive RF transmitters (TX) have attracted great attention in both literature and industry. The motivation is to implement RF circuits in a manner suiting advanced nanometer CMOS processes. To achieve that, information is encoded in the time-domain rather than voltage amplitude. READ MORE

  6. 4. Modulation Optimization for Noncoherent Optical Systems

    Author : Johnny Karout; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Direct detection; noncoherent communications; lattice codes; mutual information; fiber-optical communications; intensity modula- tion; sphere packing.; infrared communications; free-space optical communications;

    Abstract : There has been a significant improvement in high-speed electronics and optical components over the past few years, and this is one of the key enabling factors for high data rate transmission. Moreover, multi- level modulation formats, which encode information onto the carrier’s amplitude and phase, are necessary to increase the spectral efficiency of communication systems. READ MORE

  7. 5. Enhancing Direct Searches for Dark Matter : Spatial-Temporal Modeling and Explicit Likelihoods

    Author : Bart Eduard Jan Pelssers; Jan Conrad; Jochen Schieck; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Dark matter; direct detection; statistical analysis; fysik; Physics;

    Abstract : Astronomical and cosmological observations on different scales point to the existence of dark matter. In the current cosmological paradigm this dark matter accounts for about 26% of the energy-density of the universe, yet has not been directly observed. READ MORE