Search for dissertations about: "noncoherent"

Showing result 1 - 5 of 7 swedish dissertations containing the word noncoherent.

  1. 1. Modulation Optimization for Noncoherent Optical Systems

    Author : Johnny Karout; Chalmers University of Technology; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Direct detection; noncoherent communications; lattice codes; mutual information; fiber-optical communications; intensity modula- tion; sphere packing.; infrared communications; free-space optical communications;

    Abstract : There has been a significant improvement in high-speed electronics and optical components over the past few years, and this is one of the key enabling factors for high data rate transmission. Moreover, multi- level modulation formats, which encode information onto the carrier’s amplitude and phase, are necessary to increase the spectral efficiency of communication systems. READ MORE

  2. 2. Optimal Detectors for Transient Signal Families and Nonlinear Sensors : Derivations and Applications

    Author : Daniel Asraf; Mats Gustafsson; Anders Grennberg; Uppsala universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; optimal detection; transient signals; noncoherent detection; unknown arrival time; ultrasonic nondestructive testing; nonlinear sensor; stochastic resonance; Signalbehandling; Signal processing; Signalbehandling; Signal Processing; signalbehandling;

    Abstract : This thesis is concerned with detection of transient signal families and detectors in nonlinear static sensor systems. The detection problems are treated within the framework of likelihood ratio based binary hypothesis testing. READ MORE

  3. 3. Signaling for Optical Intensity Channels

    Author : Johnny Karout; Chalmers University of Technology; []
    Keywords : lattice codes; mutual information; intensity modulation; noncoherent communications; Direct detection; sphere packing.; infrared communications; free-space optical communications; fiber-optical communications;

    Abstract : With the growing popularity of social media services, e-commerce, and many other internet-based services, we are witnessing a rapid growth in the deployment of data centers and cloud computing platforms. As a result, the telecommunications industry has to continue providing additional network capacity to meet the increasing demand for bandwidth. READ MORE

  4. 4. Capacity Analysis and Receiver Design in the Presence of Fiber Nonlinearity

    Author : Kamran Keykhosravi; Chalmers University of Technology; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; perturbation theory.; Achievable rate; nonlinearity mitigation; noncoherent optics; dispersion compensation; fiber optics; channel capacity; information theory;

    Abstract : The majority of today's global Internet traffic is conveyed through optical fibers. The ever-increasing data demands have pushed the optical systems to evolve from using regenerators and direct-direction receivers to a coherent multi-wavelength network. READ MORE

  5. 5. Studies on the remineralization of white spot lesions : longitudinal assessment with quantitative light-induced fluorescence

    Author : Susan Al-Khateeb; Karolinska Institutet; Karolinska Institutet; []

    Abstract : The global aim of this work was to develop and test the light induced fluorescence method using either laser light or a regular, i.e. noncoherent light source for quantification of mineral changes in white spot lesions. Validation studies were carried out to establish the correlation between fluorescence loss and mineral loss. READ MORE