Sökning: "phase-shift"

Visar resultat 6 - 10 av 82 avhandlingar innehållade ordet phase-shift.

  1. 6. Multidimensional Modulation Formats for Coherent Optical Communication Systems

    Författare :Tobias Eriksson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; binary pulse position modulation QPSK; Fiber-optical communication; spectral efficiency; power efficiency; multidimensional position modulation.; 16-ary quadrature amplitude modulation 16QAM ; quadrature phase shift keying QPSK ; coherent detection; polarization-switched quadrature phase shift keying PS-QPSK ; 128-level set-partitioning QAM 128-SP-QAM ;

    Sammanfattning : Coherent optical receivers have enabled the use of multilevel modulation formats with high spectral efficiencies and long transmission reaches. Traditionally, modulation formats utilizing the two dimensions spanned by the amplitude and the phase of the signal have been dominating. LÄS MER

  3. 7. DSP based Chromatic Dispersion Equalization and Carrier Phase Estimation in High Speed Coherent Optical Transmission Systems

    Författare :Tianhua Xu; Sergei Popov; Gunnar Jacobsen; Jie Li; Seb Savory; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; coherent detection; chromatic dispersion; carrier phase estimation; quadrature phase shift keying; SRA - ICT; SRA - Informations- och kommunikationsteknik;

    Sammanfattning : Coherent detection employing multilevel modulation formats has become one of the most promising technologies for next generation high speed transmission systems due to the high power and spectral efficiencies. Using the powerful digital signal processing (DSP), coherent optical receivers allow the significant equalization of chromatic dispersion (CD), polarization mode dispersion (PMD), phase noise (PN) and nonlinear effects in the electrical domain. LÄS MER

  4. 8. Multidimensional Modulation Formats for Coherent Single- and Multi-Core Fiber-Optical Communication Systems

    Författare :Tobias Eriksson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; four-dimensional 4D estimates of mutual information MI ; multidimensional modulation formats; lattice based modulation; biorthogonal modulation in eight dimensions; power efficiency; 16-ary quadrature amplitude modulation 16QAM ; quadrature phase shift keying QPSK ; polarization-switched QPSK PS-QPSK ; 128-ary set-partitioning 16QAM 128-SP-16QAM ; spectral efficiency; single parity check-coded modulation; multidimensional position modulation; achievable information rate.; iber-optical communication; multicore fiber transmission; binary pulse position modulation QPSK 2PPM-QPSK ; crosstalk;

    Sammanfattning : This thesis covers multidimensional modulation formats for coherent optical communication systems including spatial division multiplexed systems using multicore fibers. The single-mode optical signal has four dimensions which are spanned by the two orthogonal polarizations and the in-phase and quadrature components. LÄS MER

  5. 9. 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. 10. Bounds on the Performance of PSK Block Codes

    Författare :Efraim Laksman; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : In wireless communication, the minimum Euclidean distance between codewords is a major factor for the ability to correct errors in messages, and it is of interest to maximize the minimum Euclidean distance. The thesis improves previously established general upper bounds on minimum Euclidean distance of phase shift keying block codes. LÄS MER