Sökning: "binary modulation"

Visar resultat 21 - 25 av 34 avhandlingar innehållade orden binary modulation.

  1. 21. Surface-normal multiple quantum well electroabsorption modulators : for optical signal processing and asymmetric free-space communication

    Författare :Stéphane Junique; Lars Thylén; Uzi Efron; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spatial light modulators; quantum wells; optical resonator; Fabry–Pérot cavity; electroabsorption modulator; free–space optical communication; Photonics; Fotonik;

    Sammanfattning : Electroabsorption is the physical phenomenon by which the absorption of light in a medium can be controlled by applying an electric field. The Quantum–Confined Stark Effect, which makes the absorption band–edge in quantum wells very field–dependent, together with the strong absorption peak provided by excitons, are the physical foundations for the success of electroabsorption modulators based on quantum well structures in telecommunication networks. LÄS MER

  3. 22. On the labeling of Signal Constellations

    Författare :Johan Lassing; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The work in this thesis studies a simple model of a digital communication system in which the transmitter operates on a sequence of information bits by grouping them into blocks of m bits and mapping such blocks onto one out of M = 2m waveforms, which is transmitted over the channel. The receiver recovers the original message by demapping the transmitted signals disturbed by noise back to m-bit blocks using maximum-likelihood symbol detection. LÄS MER

  4. 23. Phase-Sensitive Parametric Signal Processing in Optical Communications

    Författare :Abel Lorences Riesgo; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : This thesis covers the analysis of several schemes for parametric processing in fiberoptic communication systems, focusing mainly on phase-sensitive processing. Vector phase-sensitive amplifiers are characterized and phase regeneration of a dualpolarization (DP)-binary phase-shift keying signal (BPSK) signal is experimentally demonstrated. LÄS MER

  5. 24. Diffractive Optics Design

    Författare :Jörgen Bengtsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; computer-generated waveguide hologram; diffractive optics; fan-out; millimeter wave radiation; proximity effect; optimal-rotation-angle method; kinoform; integrated optics; beam shaping; outcoupling grating; scalar optics;

    Sammanfattning : Diffractive optical elements (kinoforms) change the way light propagates, and can perform very complex tasks. They can split an incident beam into any number of outgoing, and possibly focused, beams (fan-out). LÄS MER

  7. 25. Synthesis and Characterization of Acceptor Polymers for All-Polymer Solar Cells and Photodetectors

    Författare :Zhaojun Li; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; morphology; all polymer solar cells; all polymer photodetectors; conjugated polymers; charge recombination;

    Sammanfattning : The development of polymer semiconductors has become an important topic due to its advantages of low cost, easy fabrication, light weight, and capability to fabricate flexible large-area devices. For example, as the need for new clean energy sources is increasing, polymer solar cells (PSCs) are being developed rapidly and becoming a promising alternative to silicon solar cells. LÄS MER