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Visar resultat 21 - 25 av 35 avhandlingar som matchar ovanstående sökkriterier.

  1. 21. Studies on Selected Topics in Radio Frequency Digital-to-Analog Converters

    Författare :Mohammad Reza Sadeghifar; Jacob Wikner; Adam Strak; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; DAC; Telecommunication; Semi-digital FIR filter; RF DAC; Sigma Delta Modulator; DDFS;

    Sammanfattning : The network latency in fifth generation mobile technology (5G) will be around one millisecond which is much lower than in 4G technology. This significantly faster response time together with higher information capacity and ultra-reliable communication in 5G technology will pave the way for future innovations in a smart and connected society. LÄS MER

  3. 22. Adaptation in multiple input multiple output systems with channel state information at transmitter

    Författare :Jinliang Huang; Svante Signell; Anders Ahlén; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MIMO; adaptive modulation; power allocation; spectral efficiency; CSI; Electrical engineering; Elektroteknik;

    Sammanfattning : This thesis comprises two parts: the first part presents channel-adaptive techniques to achieve high spectral efficiency in a single user multiple-input multiple-output (MIMO) system; the second part exhibits a programmable and reconfigurable software-defined-radio orkbench(SDR-WB) in the Matlab/Octave environment that accommodates a variety of wireless applications. In an attempt to achieve high spectral efficiency, an adaptive modulation technique is applied at the transmitter to vary the data rate depending on the channel state information (CSI). LÄS MER

  4. 23. Phase transitions in novel superfluids and systems with correlated disorder

    Författare :Hannes Meier; Mats Wallin; Asle Sudbø; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; condensed matter physics; phase transitions; critical phenomena; spin models; quantum phase transitions; quantum fluids; superfluidity; superconductivity; disordered systems; Bose glass; dirty bosons; vortex pinning; statistical mechanics; Monte Carlo simulation; Wolff algorithm; classical worm algorithm; Wang-Landau algorithm; Fysik; Physics;

    Sammanfattning : Condensed matter systems undergoing phase transitions rarely allow exact solutions. The presence of disorder renders the situation  even worse but collective Monte Carlo methods and parallel algorithms allow numerical descriptions. LÄS MER

  5. 24. Signal Reconstruction Algorithms for Time-Interleaved ADCs

    Författare :Anu Kalidas Muralidharan Pillai; Håkan Johansson; Christian Vogel; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : An analog-to-digital converter (ADC) is a key component in many electronic systems. It is used to convert analog signals to the equivalent digital form. LÄS MER

  7. 25. How ISM properties drive Lyman Continuum Escape

    Författare :Johannes Puschnig; Matthew Hayes; Göran Östlin; Rahman Amanullah; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astrophysics; Cosmology; Extragalactics; Reionization; Lyman Continuum; Interstellar Medium; ISM; Tololo 1247-232; Astronomy; astronomi;

    Sammanfattning : The thesis introduces physical processes that are at work in astrophysical plasmas and reviews the current state of research related to the emission of ionizing photons, i.e. Lyman continuum (LyC). Star forming galaxies and active galactic nuclei are discussed as sources of LyC. LÄS MER