Open AccessMIMO carrier phase recovery for carrier-asynchronous SDM-MIMO reception based on the extended Kalman filter
Author(s) -
Kohki Shibahara,
Takayuki Mizuno,
Yutaka Miyamoto
Publication year - 2021
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.424235
Subject(s) - mimo , computer science , asynchronous communication , electronic engineering , phase noise , transmission (telecommunications) , quadrature amplitude modulation , polarization division multiplexing , spatial multiplexing , kalman filter , control theory (sociology) , bit error rate , algorithm , telecommunications , signal processing , channel (broadcasting) , engineering , decoding methods , radar , control (management) , artificial intelligence
We propose a novel phase recovery scheme designed for coherent space division multiplexing (SDM) systems with independently-operated asynchronous light sources. The proposed scheme is based on the approach of the extended Kalman filter and is referred to as multiple-input multiple-output carrier phase recovery (MIMO-CPR). In the minimum mean squared error (MMSE) sense, it simultaneously and optimally obtains estimates of the multiple phase errors arising from phase-unlocked asynchronous light sources. To ensure the scheme's application for SDM fibers with a time-varying property, we also describe a modification to incorporate a MIMO equalization scheme and analyze the computational complexity. The performance of the proposed MIMO-CPR scheme is investigated through numerical simulation, which shows that it has a tolerance for the sum linewidth symbol duration product of up to 3.4 × 10 -4 , 1.0 × 10 -4 and 2.2 × 10 -5 for QPSK, 16QAM, and 64QAM signals, respectively, if 1-dB optical signal-to-noise ratio (OSNR) penalty is allowable to achieve BER of 10 -3 . Transmission experimental results using three spatial modes in a 51-km-long few-mode fiber (FMF) also verify the applicability of the MIMO-CPR scheme to carrier-asynchronous coherent SDM-MIMO systems.