Multidimensional Mutual Information Characterization of Nonlinear Interactions over Time and Polarizations

The achievable information rate is experimentally estimated in coherent fiber optical communication for different four dimensional descriptions of the channel to the demapper. Polarization-multiplexed 16-ary quadrature amplitude modulation with channel symbolrates of either 10 or 20 Gbaud are investigated in experiments over both erbium doped fiber amplifier based links and Raman aplified links. We show that doing demapping over two consecutive time slots rather than two orthogonal polarization states can be beneficial, although both cases show gain over conventional two-dimensional demappers. A Index Terms--IEEE, IEEEtran, journal, LTEX, paper, template.