Search for dissertations about: "optical communication"

Showing result 6 - 10 of 229 swedish dissertations containing the words optical communication.

  2. 6. Multidimensional Modulation Formats for Coherent Optical Communication Systems

    Author : Tobias Eriksson; Chalmers tekniska högskola; []
    Keywords : 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 ;

    Abstract : 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. READ MORE

  4. 7. Dynamic Resource Provisioning and Survivability Strategies in Optical Networks

    Author : Jawwad Ahmed; Lena Wosinska; Andrea Fumagalli; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optical networks; passive optical networks; wavelength; routing; Survivability; protection; restoration; SRA - ICT; SRA - Informations- och kommunikationsteknik;

    Abstract : Optical networks based on Wavelength Division Multiplexing (WDM) technology show many clear benefits in terms of high capacity, flexibility and low power consumption. All these benefits make WDM networks the preferred choice for today’s and future transports solutions which are strongly driven by a plethora of emerging online services. READ MORE

  5. 8. Implementation and Evaluation of Signal Processing Circuits for Optical Communication

    Author : Erik Börjeson; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Adaptive Equalization; Carrier Phase Recovery; Digital Signal Processing; Application-Specific Integrated Circuits; Communication Systems; Fiber-Optic Communication;

    Abstract : The digital signal processing (DSP) circuits used in the fiber-optic communication links that make up the backbone of the Internet can be a significant contributor the over-all power dissipation of a link. As the number of connected users and their bandwidth requirements are expected to continue to grow over the coming years, the development of power-efficient high-throughput DSP systems is a critical factor in enabling this growth. READ MORE

  6. 9. Towards Secure Synchronous Communication Architectures for Wireless Networks

    Author : Kasun Hewage; Thiemo Voigt; Shahid Raza; Matthias Hollick; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Datagram Transport Layer Security; Synchronous Transmissions; Denial-of-service Attacks; Transmission Control Protocol; Communication Security; Time Synchronisation; Optical Wireless Communication; Networked Embedded Systems; Internet of Things; Electrical Engineering with Specialisation in Networked Embedded Systems; Elektroteknik med inriktning mot nätverksbaserade inbyggda system;

    Abstract : The vision behind the Internet of Things (IoT) revolves around creating a connected ecosystem where devices, people, and systems collaborate seamlessly, unlocking new possibilities, improving efficiency, and enhancing our daily lives. IoT encloses many device classes, including low-power wireless devices that rely on batteries or energy harvesting. READ MORE

  7. 10. 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