Search for dissertations about: "Coherent communications"

Showing result 1 - 5 of 51 swedish dissertations containing the words Coherent communications.

  2. 1. Microresonator combs for coherent optical communications

    Author : Attila Fülöp; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fiber-optic communication; nonlinear optics; integrated optics devices; four-wave mixing; microresonators;

    Abstract : This thesis covers the study of microresonator-based optical frequency combs for use in coherent optical communication links. Current links typically utilize several free-running lasers to achieve wavelength-division multiplexing (WDM). READ MORE

  4. 2. Multidimensional Constellation Shaping for Coherent Optical Communication Systems

    Author : Ali Mirani; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lattice-based constellations; geometric shaping; probabilistic shaping; multidimensional modulation format; Voronoi constellation; constellation shaping; optical communications; coherent receiver;

    Abstract : To overcome the increasing demands for Internet traffic, exploiting the available degrees of freedom in optical communication systems is necessary. In this thesis, we study how constellation shaping can be achieved in various dimensions and how various shaping schemes affect the whole performance in real systems. READ MORE

  5. 3. Modulation Optimization for Noncoherent Optical Systems

    Author : Johnny Karout; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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

  6. 4. Signaling for Optical Intensity Channels

    Author : Johnny Karout; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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

  7. 5. Phase Noise Tolerant Modulation Formats and DSP Algorithms for Coherent Optical Systems

    Author : Jaime Rodrigo Navarro; Sergei Popov; Gunnar Jacobsen; Richard Schatz; Xiaodan Pang; Oskars Ozolins; Gabriella Bosco; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optical communications; carrier phase recovery; blind phase search; circular quadrature amplitude modulation; CmQAM; coherent optical communications; digital signal processing; carrier phase estimation; equalization enhanced phase noise; EEPN; Telecommunication; Telekommunikation;

    Abstract : Coherent detection together with multilevel modulation formats has the potential to significantly increase the capacity of existing optical communication systems at no extra cost in signal bandwidth. However, these modulation formats are more susceptible to the impact of different noise sources and distortions as the distance between its constellation points in the complex plane reduces with the modulation index. READ MORE