Sökning: "quadrature phase shift keying QPSK"
Visar resultat 1 - 5 av 11 avhandlingar innehållade orden quadrature phase shift keying QPSK.
1. Multidimensional Modulation Formats for Coherent Optical Communication Systems
Sammanfattning : 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. LÄS MER
2. Fiber-Optic Systems with Coherent Detection and Four-Dimensional Modulation
Sammanfattning : To increase the data rates of fiber-optic communication systems, modulation formats withhigher spectral efficiency and/or higher power efficiency than binary formats are of greatinterest. These formats require coherent detection and this thesis has been dedicated toinvestigating both novel modulation formats and two different types of coherent systems. LÄS MER
3. Multidimensional Modulation Formats for Coherent Single- and Multi-Core Fiber-Optical Communication Systems
Sammanfattning : This thesis covers multidimensional modulation formats for coherent optical communication systems including spatial division multiplexed systems using multicore fibers. The single-mode optical signal has four dimensions which are spanned by the two orthogonal polarizations and the in-phase and quadrature components. LÄS MER
4. DSP based Chromatic Dispersion Equalization and Carrier Phase Estimation in High Speed Coherent Optical Transmission Systems
Sammanfattning : Coherent detection employing multilevel modulation formats has become one of the most promising technologies for next generation high speed transmission systems due to the high power and spectral efficiencies. Using the powerful digital signal processing (DSP), coherent optical receivers allow the significant equalization of chromatic dispersion (CD), polarization mode dispersion (PMD), phase noise (PN) and nonlinear effects in the electrical domain. LÄS MER
5. On interference suppression techniques for communication systems
Sammanfattning : The work presented in this thesis concerns interferencesuppression techniques in two different communication systems.In the first part we study fiber-optic systems with practical non-ideal transmitters and receivers, which give rise to intersymbol interference (ISI). LÄS MER