Extremely Higher-Order Modulation Formats

Research output: Chapter in Book/Report/Conference proceedingChapter

9 Citations (Scopus)


We provide on overview of fundamental technologies and recent challenges on extremely higher-order quadrature amplitude modulation (QAM) such as 256-1024 levels, toward the realization of an ultrahigh spectral efficiency approaching the Shannon limit. Key components required for such a higher-order QAM transmission are described in detail, including a coherent light source, an optical phase-locked loop, an IQ modulator, and a digital demodulator. We also present recent demonstrations of single-carrier 1024 QAM, 256 QAM-OFDM, and OTDM-RZ/32 QAM transmissions realized with these fundamental technologies.

Original languageEnglish
Title of host publicationOptical Fiber Telecommunications VIB
Subtitle of host publicationSystems and Networks: Sixth Edition
PublisherElsevier Inc.
Number of pages40
ISBN (Electronic)9780123972378
ISBN (Print)9780123969606
Publication statusPublished - 2013 May 13


  • Coherent transmission
  • Digital signal processing
  • Frequency-stabilized laser
  • Multi-level modulation
  • Nyquist filter
  • Optical phase-locked loop
  • Orthogonal frequency division multiplexing (OFDM)
  • Quadrature amplitude modulation (QAM)
  • Shannon limit
  • Spectral efficiency

ASJC Scopus subject areas

  • Engineering(all)


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