Open AccessNarrow optical filtering in phase modulated communication links
Author(s) -
Shapiro E.G.,
Shapiro D.A.
Publication year - 2013
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2012.3625
Subject(s) - differential phase , dispersion (optics) , keying , optical communication , sequence (biology) , phase (matter) , phase shift keying , mathematics , optics , physics , optical filter , modulation (music) , differential (mechanical device) , bit error rate , topology (electrical circuits) , telecommunications , computer science , algorithm , quantum mechanics , decoding methods , chemistry , combinatorics , acoustics , thermodynamics , biochemistry
Two variants of differential phase‐shift keying with π and π/2 shifts are compared theoretically. The expressions are derived for dispersion averaged over all the realisations of the bit sequence. It is shown that in the presence of strong optical filtering the π/2 scheme yields less dispersion of pulses and much better Q‐factor in agreement with the experiment. The inequality is confirmed by numerical calculation.