Open AccessDoubling direct-detection data rate by polarization multiplexing of 16-QAM without active polarization control
Author(s) -
Moshe Nazarathy,
A. Agmon
Publication year - 2013
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.21.031998
Subject(s) - polarization division multiplexing , multiplexing , optics , quadrature amplitude modulation , polarization (electrochemistry) , physics , computer science , multiplexer , electronic engineering , bit error rate , telecommunications , wavelength division multiplexing , decoding methods , engineering , wavelength , chemistry
We introduce and simulate a technique enabling to utilize the polarization dimension in direct-detection optical transmission, supporting polarization multiplexing (POL-MUX) over direct-detection (DD) methods previously demonstrated for a single polarization such as direct-detection OFDM. POL-MUX is currently precluded in self-coherent DD with remotely transmitted pilot, as signal x pilot components may randomly fade out. We propose POL-MUX transmission of advanced modulation formats, such as 16-QAM and higher, by means of a novel low-complexity photonic integrated optical front-end and adaptive 3x2 MIMO DSP. The principle of operation is as follows: an additional X x Y cross-polarizations signal is generated, providing three projections onto an over-complete frame of three dependent vectors. This enables to resiliently reconstruct the received state of polarization even when the remotely transmitted pilot fades along one of the received polarization axes.