Open AccessBlind polarization demultiplexing by constructing a cost function for coherent optical PDM-OFDM
Author(s) -
Zhenming Yu,
Minghua Chen,
Hongwei Chen,
Xingwen Yi,
Sigang Yang,
Shizhong Xie
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.018511
Subject(s) - subcarrier , orthogonal frequency division multiplexing , subcarrier multiplexing , computer science , polarization division multiplexing , multiplexing , quadrature amplitude modulation , electronic engineering , optics , modulation (music) , polarization mode dispersion , physics , bit error rate , signal processing , telecommunications , optical fiber , engineering , channel (broadcasting) , acoustics , radar
We propose a training symbols-free polarization demultiplexing method by constructing a cost function (CCF-PDM) for coherent optical PDM-OFDM. This method is applicable for high-speed, wide-bandwidth OFDM signals, different subcarrier modulation formats and long-haul transmission. It shows comparable performance with that of conventional method but without overhead and converges fast. Since the neighboring subcarriers experience similar polarization effects, we set the initial matrix parameters by the neighboring subcarrier to reduce the number of iteration for the gradient algorithm and prevent swapping the data of the two orthogonal polarizations. We verify this method in experiment by transmitting 66.6-Gb/s PDM-OFDM signal with 4QAM subcarrier modulation over 5440 km SSMF and 133.3-Gb/s PDM-OFDM signal with 16QAM subcarrier modulation over 960 km SSMF respectively. We compare its performance with that of training symbols. We also analyze the convergence speed of this method.