Open AccessChromatic dispersion equalization FIR filter design based on discrete least-squares approximation
Author(s) -
Dawei Wang,
Hao Jiang,
Guowei Liang,
Qianxin Zhan,
Zikang Su,
Zhaohui Li
Publication year - 2021
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.430955
Subject(s) - finite impulse response , blind equalization , filter design , digital filter , root raised cosine filter , equalization (audio) , computer science , weighting , passband , linear filter , impulse response , filter (signal processing) , optics , fourier transform , mathematics , algorithm , physics , band pass filter , acoustics , mathematical analysis , decoding methods , computer vision
Chromatic dispersion (CD) equalization is one of the core tasks of the digital signal processing (DSP) chain in modern optical coherent receivers. A conventional impulse-invariant method for designing the CD equalization filter is revisited, improved by proper weighting, and reinterpreted as a Fourier series. To improve upon a direct evaluation of the passband least-squares (LS) approximation, we propose to design a CD equalization finite impulse response (FIR) filter based on a discrete LS approximation. The proposed method avoids numerical evaluation of nontrivial functions and relies only on Fourier transform. Its flexibility is corroborated by a filter design demonstration of joint matched filtering and CD equalization.