Comparison of twin-SSB modulation schemes

Ryoto Nakagawa, Yuya Takanashi, Moriya Nakamura

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We investigated and compared the performances of three different types of optical twin-single sideband (twin-SSB) modulation methods. Twin-SSB can transmit two different signals on lower side-band (LSB) and upper side-band (USB), and has been studied as a technique to improve spectral efficiency. Twin-SSB arranges the spectra side-by-side without any spectral spacing. Dispersion tolerance of twin-SSB is as high as that of conventional SSB schemes. The twin-SSB modulation can be performed by using a dual-polarization quadrature phase shift keying (DP-QPSK) modulator, a QPSK modulator, or a single Mach-Zehnder modulator (MZM). The twin-SSB with the three modulation methods need to be modulated at a limited linear domain of the optical field output function of the modulator. Therefore, if we apply a large electrical modulation signal to the modulators to decrease the optical loss, the nonlinear characteristics of the modulators degrade the performance of the twin-SSB signals. We investigated the modulation performance by changing the amplitude of the electrical modulation signal for the modulators, and investigated the optimal conditions of the twin-SSB modulation methods. We also performed numerical simulations of 50-km standard single mode fiber (SSMF) transmission of the twin-SSB signals with the optimal modulation conditions, and evaluated the error vector magnitude (EVM) performances of the transmitted signals. The results revealed that the EVM performances of the twin-SSB signals using a DP-QPSK modulator and a QPSK modulator were superior to that of a single MZM.

Original languageEnglish
Title of host publicationNext-Generation Optical Communication
Subtitle of host publicationComponents, Sub-Systems, and Systems IX
EditorsGuifang Li, Xiang Zhou
PublisherSPIE
ISBN (Electronic)9781510633810
DOIs
Publication statusPublished - 1 Jan 2020
EventNext-Generation Optical Communication: Components, Sub-Systems, and Systems IX 2020 - San Francisco, United States
Duration: 5 Feb 20206 Feb 2020

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume11309
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Conference

ConferenceNext-Generation Optical Communication: Components, Sub-Systems, and Systems IX 2020
CountryUnited States
CitySan Francisco
Period5/02/206/02/20

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Keywords

  • Digital signal processing
  • Electrical butterfly operation
  • Mach-Zehnder modulator
  • Modulation parameter
  • Optical fiber communications
  • Optical modulation
  • QPSK modulator
  • Twin-SSB

Cite this

Nakagawa, R., Takanashi, Y., & Nakamura, M. (2020). Comparison of twin-SSB modulation schemes. In G. Li, & X. Zhou (Eds.), Next-Generation Optical Communication: Components, Sub-Systems, and Systems IX [113090S] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 11309). SPIE. https://doi.org/10.1117/12.2545608