Sökning: "Optical processing"

Visar resultat 16 - 20 av 341 avhandlingar innehållade orden Optical processing.

  1. 16. 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. 17. On Nonlinear Compensation Techniques for Coherent Fiber-Optical Channel

    Författare :Naga Vishnukanth Irukulapati; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; performance limits.; nonlinear compensation; factor graphs; fiber-optical communications; near-MAP detector; Digital backpropagation;

    Sammanfattning : Fiber-optical communication systems form the backbone of the internet, enabling global broadband data services. Over the past decades, the demand for high-speed communications has grown exponentially. One of the key techniques for the efficient use of existing bandwidth is the use of higher order modulation formats along with coherent detection. LÄS MER

  4. 18. Quantitative image analysis : a focus on automated characterization of structures in optical microscopy of iron ore pellets

    Författare :Frida Nellros; Carolina Wählby; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

    Sammanfattning : Sintering occurs in many types of material such as iron, ceramics and snow, typically during thermal treatment, and aects the material properties, particularly the strength, by the bonding of particles into a coherent structure. In order to improve the mechanical strength in magnetite iron ore pellets it is important to be able to characterize and quantitatively measure the degree of sintering and features that impact the process of sintering. LÄS MER

  5. 19. High Spectral Efficiency Fiber-Optic Transmission Systems Using Pilot Tones

    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; Coherent Optical Communications; Analog Optical Signal Processing;

    Sammanfattning : Modern fiber-optic communication systems combine state-of-the-art components with powerful digital signal processing (DSP) to maximize the system spectral efficiency (SE). Systems rely on wavelength-division multiplexing, including superchannel transmission, to enable transmission over the available bandwidth which reaches about 10 THz when accounting for the so-called C and L bands. LÄS MER

  7. 20. Aspects of Power Consumption in Coherent Fiber-Optical Communication Systems

    Författare :Lars Lundberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optical frequency comb; Fiber-optical communication; power consumption; carrier-recovery; Raman amplification; energy-efficiency; optical amplifier; digital signal processing; coherent detection; erbium-doped fiber amplifier; phase-tracking;

    Sammanfattning : The power consumption of coherent fiber-optical communication systems is becoming increasingly important, for both environmental and economical reasons. The data traffic on the Internet is increasing at a faster pace than that at which optical network equipment is becoming more energy efficient, which means that the overall power consumption of the Internet is increasing. LÄS MER