Sökning: "Information distortion"

Visar resultat 41 - 45 av 241 avhandlingar innehållade orden Information distortion.

  1. 41. Multicarrier modulation : duplexing design and interference/distortion mitigation

    Författare :Rickard Nilsson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

    Sammanfattning : Aspects of modern communication systems is the overall theme of this thesis with emphasis placed on multicarrier modulation. The work considers four facets of such systems; namely duplexing design, interference mitigation, channel estimation and multiuser detection. LÄS MER

  3. 42. Active Transmitter Antenna Array Modeling for MIMO Applications

    Författare :Parastoo Taghikhani; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; beam steering; Active antenna array; active impedance; hybrid beamforming transmitter; MIMO transmitter; far-field nonlinear distortion; millimeter wave; modeling.;

    Sammanfattning : The rapid growth of data traffic in mobile communications has attracted interests to the Multiple-Input-Multiple-Output (MIMO) communication systems at millimeter-wave (mmWave) frequencies.  MIMO systems exploit active transmitter antenna arrays for higher energy efficiency and providing beamforming flexibility. LÄS MER

  4. 43. All-optical nonlinearity mitigation in fiber-optic communications

    Författare :Henrik Eliasson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fiber-optic communications; phase-sensitive amplifiers; optical phase conjugation; nonlinear optics;

    Sammanfattning : The two main factors limiting the data throughput in modern fiber-optic communication links are the noise added by amplifiers and the nonlinear response of the optical fiber due to the Kerr effect. Today there are communication systems operating remarkably close to the limits set by these two factors. LÄS MER

  5. 44. Fiber-Optic Systems with Coherent Detection and Four-Dimensional Modulation

    Författare :Martin E Sjödin; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; intradyne; polarization-switched QPSK; quadrature phase-shift keying QPSK ; coherent detection; self-homodyne; wavelength-division multiplexing; 16-ary quadrature amplitude modulation; self-phase modulation; 128-SP-QAM; polarization multiplexing; pilot tone;

    Sammanfattning : To increase the data rates of fiber-optic communication systems, modulation formats withhigher spectral efficiency and/or higher power efficiency than binary formats are of greatinterest. These formats require coherent detection and this thesis has been dedicated toinvestigating both novel modulation formats and two different types of coherent systems. LÄS MER

  7. 45. Power Measurement Techniques for Nonsinusoidal Conditions. The Significance of Harmonics for the Measurement of Power and other AC quantities

    Författare :Stefan Svensson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; non-sinusoidal; reactive; harmonics; power; sampling wattmeter;

    Sammanfattning : The increased application of power electronics and other non-linear loads makes it necessary to re-evaluate the measuring techniques used in the power system, and the measuring problems these loads cause. An instrument utilising digital sampling techniques has been built and evaluated at the Swedish National Testing and Research Institute (SP). LÄS MER