CROSSTALK-FREE HIGH-DIMENSIONAL CONSTELLATIONS FOR DUAL-POLARIZED NONLINEAR FIBER-OPTIC COMMUNICATIONS

摘要

PROBLEM TO BE SOLVED: To provide a method of reducing time-varying polarization crosstalk due to XPolM by transmitting multi-dimensional orthogonal constellations.;SOLUTION: Three variants of crosstalk-free constellations are provided: Grassmann constellations, unitary constellations, and rotation codes. The method uses the Grassmann constellations and the unitary constellations to deal with fiber nonlinearity by applying as a polarization-time coding. The rotation codes exploit a fiber channel characteristic to improve performance and to reduce computational complexity. The underlying orthogonality behind those constellations enables a receiver to decode the constellations as if there is no polarization crosstalk. Moreover, the required computational complexity at the receiver is significantly reduced because neither a crosstalk canceller nor a channel estimator is needed.;COPYRIGHT: (C)2013,JPO&INPIT