Title
Replacing the Soft-decision FEC Limit Paradigm in the Design of Optical Communication Systems
Abstract
The FEC limit paradigm is the prevalent practice for designing optical communication systems to attain a certain bit-error rate (BER) without forward error correction (FEC). This practice assumes that there is an FEC code that will reduce the BER after decoding to the desired level. In this paper, we challenge this practice and show that the concept of a channel-independent FEC limit is invalid for soft-decision bitwise decoding. It is shown that for low code rates and high order modulation formats, the use of the soft-decision FEC limit paradigm can underestimate the spectral efficiencies by up to 20%. A better predictor for the BER after decoding is the generalized mutual information, which is shown to give consistent post-FEC BER predictions across different channel conditions and modulation formats. Extensive optical full-field simulations and experiments are carried out in both the linear and nonlinear transmission regimes to confirm the theoretical analysis.
Year
DOI
Venue
2015
10.1109/JLT.2015.2450537
Lightwave Technology, Journal of
Keywords
Field
DocType
modulation,mutual information,decoding,forward error correction,bit error rate
Forward error correction,Nonlinear system,Computer science,Optical communication,Communication channel,Electronic engineering,Modulation,Mutual information,Decoding methods,Bit error rate
Journal
Volume
Issue
ISSN
PP
99
0733-8724
Citations 
PageRank 
References 
15
1.07
30
Authors
4
Name
Order
Citations
PageRank
Alex Alvarado111027.09
E. Agrell295991.69
domanic lavery34413.38
robert maher4173.18