Sökning: "coded modulation"

Visar resultat 16 - 20 av 650 avhandlingar innehållade orden coded modulation.

1. 16. Analysis of Some Convolutional Coding Constructions

   Författare :Karin Engdahl; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbo-codes; low-density parity-check convolutional codes; low-density codes; PSK; PAM; QAM; coded modulation; multilevel coding; convolutional codes; multilevel modulation; iterative decoding; Informatics; systems theory; Informatik; systemteori;

   Sammanfattning : This thesis focuses on different convolutional coding constructions for digital communication systems, and on methods to analyze these constructions. The work presented in the thesis can be divided into three main areas; error probability bounds for convolutional codes, analysis of multilevel modulation, and investigation of low-density parity-check convolutional codes. LÄS MER

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

   Författare :Marco Forzati; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 18. Modulation of retinal progenitors : A bird’s-eye view of retinal regeneration and disease

   Författare :Dardan Konjusha; Finn Hallböök; Rusty Lansford; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Developmental neurobiology; Retinoblastoma; MYCN; Cone photoreceptor; Nolz1; Endothelin; Müller cells;

   Sammanfattning : The cell populations of the retina and their intricate organization provide us with one of the most important senses – vision. All retinal cell populations are derived from a common progenitor pool as a result of tight regulation of proliferation, differentiation, dedifferentiation, and programmed cell death. LÄS MER

5. 19. Multidimensional Modulation Formats for Coherent Optical Communication Systems

   Författare :Tobias Eriksson; Chalmers tekniska högskola; []
   Nyckelord :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 ;

   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

7. 20. Multi-level modulation formats for high-speed optical transmission systems

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

   Sammanfattning : 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. LÄS MER