Open AccessSpectral efficiency limits of pre-filtered modulation formats
Author(s) -
Yi Cai,
J.-X. Cai,
A.N. Pilipetskii,
G. Mohs,
Neal S. Bergano
Publication year - 2010
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.020273
Subject(s) - modulation (music) , limit (mathematics) , optics , delta modulation , bandwidth (computing) , spectral efficiency , intensity modulation , physics , optical filter , phase modulation , mathematics , computer science , telecommunications , pulse amplitude modulation , mathematical analysis , acoustics , channel (broadcasting) , detector , phase noise , pulse (music)
We investigate the spectral efficiency (SE) limit of pre-filtered modulation in optical fiber communication systems. We show that pre-filtering induced symbol correlation generates a modulation with memory and, thus, a higher SE limit than that of the original memoryless modulation. The SE limits of a series of modulation formats with varying number L of correlated symbols producing 50% of the original bandwidth are evaluated, which approach the SE limit of a modulation format with 50% pre-filtering as L --> ∞. We show that the SE limit of a modulation format with L correlated symbols approximates a lower bound for the SE limit of the corresponding pre-filtered format.