Digital post-processing against inline spectrum narrowing caused by optical node traversals

Abstract

This paper evaluates performance of digital coherent receivers that executes partial-response spectrum shaping and MLSE to mitigate the inline-spectrum-narrowing impairment caused by traversing multiple optical nodes in photonic networks. Extensive computer simulations confirm that the maximum transmission distances and hop counts of DP 4-QAM and 16-QAM signals in highly dense WDM networks are substantially extended.