Sökning: "spectral efficiency"

Visar resultat 1 - 5 av 236 avhandlingar innehållade orden spectral efficiency.

  1. 1. Spectral Efficiency and Fairness Maximization in Full-Duplex Cellular Networks

    Författare :Jose Mairton B. da Silva Jr.; Carlo Fischione; Gabor Fodor; Ioannis Krikidis; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; full-duplex; power control; user assignment; cellular networks; fairness; spectral efficiency; Telecommunication; Telekommunikation;

    Sammanfattning : Future cellular networks, the so-called 5G, are expected to provide explosive data volumes and data rates. To meet such a demand, the research communities are investigating new wireless transmission technologies. One of the most promising candidates is in-band full-duplex communications. LÄS MER

  3. 2. Heat Transfer and Energy Efficiency in Infrared Paper Dryers

    Författare :Magnus Pettersson; Avdelningen för kemiteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; experimental; modelling; electricity; gas; efficiency; energy; drying; dryer; heat transfer; radiation; paper; infrared; IR; coating; Chemical technology and engineering; Kemiteknik och kemisk teknologi;

    Sammanfattning : Infrared (IR) dryers are widely used in the paper industry, mainly in the production of coated paper grades. The thesis deals with various aspects of heat transfer and energy use in infrared heaters and dryers as employed in the paper industry. Both gas-fired and electric IR dryers are considered and compared. LÄS MER

  4. 3. 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

  5. 4. 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

  7. 5. High spectral efficiency transmission using optical frequency combs

    Författare :Mikael Mazur; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Optical frequency combs; Superchannels; Coherent optical communication;

    Sammanfattning : Modern long-haul optical communication systems transmit data on all available single-mode fiber dimensions, time, polarization, wavelength, phase and amplitude. Powerful digital signal processing and forward error correction has pushed the per-channel throughput towards its theoretical limits and the bandwidth is limited by the erbium-doped fiber amplifiers. LÄS MER