Search for dissertations about: "modulation format"

Showing result 1 - 5 of 28 swedish dissertations containing the words modulation format.

2. 1. Multi-level modulation formats for high-speed optical transmission systems

   Author : Ekawit Tipsuwannakul; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quadrature amplitude modulation; spectral efficiency; differential detection; modulation format; coherent detection; phase shift keying;

   Abstract : Over the past several years, the use of multi-level modulation formats has enabledsignificant improvements in the field of optical fiber communication, particularlyin terms of per-channel bit-rate (i.e., line-rate) and spectral efficiency (SE), byencoding multiple bits per symbol. READ MORE

4. 2. The alternate-phase return-to-zero modulation format in high-speed optical-fibre communications

   Author : Marco Forzati; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-speed optical transmission; return-to-zero; nonlinear optics; dispersion management; phase modulation; modulation formats; Fibre optics communication; fibres;

   Abstract : Increasing the channel bit rate is an efficient way to upgrade traffic capacity in installed transmission links. At bit rates of the order of 40 Gb/s, on-off keying transmission becomes severely impaired by non-linear effects,particularly Intra-channel Cross-Phase Modulation (IXPM) and Intra-channel Four-Wave Mixing (IFWM), which cause pulses in different bit slots to interact with each-other. READ MORE

5. 3. 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

6. 4. Fiber-Optic Systems with Coherent Detection and Four-Dimensional Modulation

   Author : Martin E Sjödin; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; intradyne; polarization-switched QPSK; quadrature phase-shift keying QPSK ; coherent detection; self-homodyne; wavelength-division multiplexing; 16-ary quadrature amplitude modulation; self-phase modulation; 128-SP-QAM; polarization multiplexing; pilot tone;

   Abstract : 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. READ MORE

7. 5. Multilevel Modulation and Transmission in VCSEL-based Short-range Fiber Optic Links

   Author : Tamas Lengyel; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; IM DD; NRZ OOK; intensity modulation; 3-PAM; inter-symbol interference; Data communication; multimode fiber; vertical cavity surface emitting lasers; 4-PAM; optical interconnects; short-range fiber optic links;

   Abstract : As the demand for ever higher throughput short-range optical links is growing, research and industry associations have shown increased interest in multilevel modulation formats, such as the four leveled pulse amplitude modulation, referred to as 4-PAM. As on-off keying (OOK) persists to be the choice for low latency applications, for example high performance computing, datacenter operators see 4-PAM as the next format to succeed current OOK-based optical interconnects. READ MORE