Open AccessDigital coherent superposition for performance improvement of spatially multiplexed coherent optical OFDM superchannels
Author(s) -
Xiang Liu,
S. Chandrasekhar,
A.H. Gnauck,
Peter J. Winzer,
Sebastian Randel,
Steve Corteselli,
A. R. Chraplyvy,
R.W. Tkach,
Bin Zhu,
T. F. Taunay,
M. Fishteyn
Publication year - 2012
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.20.00b595
Subject(s) - optics , transmission (telecommunications) , quadrature amplitude modulation , superposition principle , multiplexing , orthogonal frequency division multiplexing , scrambling , physics , wavelength division multiplexing , polarization division multiplexing , transmitter , subcarrier multiplexing , electronic engineering , spectral efficiency , signal to noise ratio (imaging) , computer science , qam , telecommunications , bit error rate , subcarrier , algorithm , engineering , channel (broadcasting) , wavelength , quantum mechanics
We demonstrate the use of digital coherent superposition to improve the performance of space-division-multiplexed (SDM) 676-Gb/s OFDM-16QAM superchannels, achieving ~4 dB improvement in OSNR by using two SDM copies and 1075-km (14 x 76.8 km) transmission over a seven-core-fiber with an effective aggregate spectral efficiency of 23.7 b/s/Hz. We further show that the performance improvement from the coherent superposition is retained in the nonlinear transmission regime through coordinated scrambling of signal constellations at the transmitter and appropriate unscrambling at the receiver, by using a series of simple scrambling functions.