Partial Differential Phase Shift Keying - Theory and Motivation

TL;DR

This paper investigates the benefits of partial Differential Phase Shift Keying in optical communications, providing both numerical and analytical insights into its ability to mitigate signal deformation caused by spectral narrowing.

Contribution

The paper offers the first analytical explanation for the effect of partial DPSK in compensating spectral narrowing, supported by numerical simulations and a phenomenological relation.

Findings

Analytical model matches simulation results with high accuracy.

Derived a relation between optimal Free Spectral Range and channel bandwidth.

Demonstrated partial DPSK's effectiveness in spectral narrowing scenarios.

Abstract

Recently, many evidences demonstrate that partial Differential Phase Shift Keying (i.e., when the delay inside the Delay Interferometer is shorter than the symbol period) can partially compensate the signal deformation caused by spectrally narrowing the optical channel (by interleavers, add-drop elements, WDM filters, etc.). In this paper the source of this effect is investigated with numerical simulations and, to the best of our knowledge for the first time, analytically. We found that our analytical analysis matched the simulation results with high accuracy. Furthermore, a phenomenological relation, which relates the optimum Free Spectral Range to the channel bandwidth, was derived.