Sökning: "spectral shaping"

Visar resultat 1 - 5 av 27 avhandlingar innehållade orden spectral shaping.

  1. 1. Inverse Problems in Analytic Interpolation for Robust Control and Spectral Estimation

    Författare :Johan Karlsson; Anders Lindquist; Alberto Isidori; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nevanlinna-Pick Interpolation; Approximation; Model Reduction; Robust Control; Gap-robustness; Sensitivity Shaping; Entropy functional; Spectral Estimation; Weak*-topology; Monge-Kantorovic Transportation; Optimization; systems theory; Optimeringslära; systemteori;

    Sammanfattning : This thesis is divided into two parts. The first part deals with theNevanlinna-Pick interpolation problem, a problem which occursnaturally in several applications such as robust control, signalprocessing and circuit theory. We consider the problem of shaping andapproximating solutions to the Nevanlinna-Pick problem in a systematicway. LÄS MER

  3. 2. Voronoi Constellations for Coherent Fiber-Optic Communication Systems

    Författare :Shen Li; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; coded modulation; constellation shaping; geometric shaping; forward error correction coding; lattices; Voronoi constellations.; multidimensional modulation formats; Achievable information rates; coherent fiber-optic communications;

    Sammanfattning : The increasing demand for higher data rates is driving the adoption of high-spectral-efficiency (SE) transmission in communication systems. The well-known 1. LÄS MER

  4. 3. Measurement and Control of Attosecond Light Fields

    Författare :Erik Mansten; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pulse characterization; Spectral signature; Two-color generation; Pulse compression; Attosecond pulse trains; High-order harmonics; Pulse shaping; Tunable; Fysicumarkivet A:2009:Mansten;

    Sammanfattning : Attosecond pulses are used to study electron dynamics in atoms and molecules. In this thesis, schemes to control the generation of attosecond pulses and pulse-shaping techniques to compress the pulses are presented. Generation of attosecond pulses requires high intensity, which is reached by focusing a pulsed femtosecond laser. LÄS MER

  5. 4. On Probabilistic Shaping and Learned Decoders with Application to Fiber-Optic Communications

    Författare :Andreas Buchberger; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Error correcting codes; learned decoders; machine learning; iterative decoding; probabilistic shaping; fiber-optic communications; pruning;

    Sammanfattning : We live in an ubiquitously connected world whose backbone are optical fibers. Achieving high spectral efficiencies and hence high transmission rates requires a careful combination of forward error correction (FEC) and higher-order modulation. This is referred to as coded modulation. LÄS MER

  7. 5. An Event-Reconstructing Silicon Detector for 1 µm Resolution Spectral Computed Tomography

    Författare :Christel Sundberg; Mats Danielsson; Julia Herzen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photon-counting; silicon detector; spectral computed tomography; subpixel resolution; dose efficiency; coincidence tracking; event reconstruction; fotonräknande; kiseldetektor; spektral datortomografi; subpixelupplösning; doseffektivitet; koincidensspårning; händelserekonstruktion; Fysik; Physics;

    Sammanfattning : Computed tomography (CT) is a medical imaging modality in which cross-sectional images of the human body are created using x-rays. Commercial CT scanners utilize energy-integrating detectors to measure the x-ray attenuation. However, photon-counting detectors with energy-discriminating abilities have started to emerge. LÄS MER