Abstract
This paper, for the first time, experimentally presents direct comparisons of two
25 GHz spaced wavelength division multiplexing (WDM) systems using conventional
dual-polarization (DP) 16-ary quadrature amplitude modulation and duobinary-shaped
DP-quadrature phase shift keying (QPSK) modulation. Both systems operate at the same bit
rate per channel of 112 Gbit/s, yielding a spectral efficiency of 4.1 bit/s/Hz. The
comparisons are conducted for three different cases, i.e., the back-to-back sensitivity,
the nonlinear tolerance over a 640-km standard single-mode fiber link, and the
phase-noise tolerance (by means of simulations). The results show that the
duobinary-shaped DP-QPSK system not only provides a 3.4 dB superior back-to-back
sensitivity, but also exhibits a 3 dB higher tolerance against nonlinear impairments
after 640 km transmission with three WDM channels. In addition, the numerical results
indicate that both investigated systems provide similar tolerances to the laser phase
noise given that the block length used in the carrier phase estimation is
optimized.
© 2012 IEEE
PDF Article
More Like This
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription
Add to BibSonomy