Interference Focusing for Mitigating Cross-Phase Modulation in a Simplified Optical Fiber Model

TL;DR

This paper introduces interference focusing, a novel technique to mitigate cross-phase modulation in optical fibers, enabling each carrier to achieve full capacity pre-log without needing channel variations or global information.

Contribution

The paper proposes a new interference focusing method that doubles the capacity pre-log in optical fiber channels with cross-phase modulation effects.

Findings

Interference focusing achieves capacity pre-log of 1 for each carrier.

The method does not require channel time variations or global channel state information.

Generalizations to multiple carriers are discussed.

Abstract

A memoryless interference network model is introduced that is based on non-linear phenomena observed when transmitting information over optical fiber using wavelength division multiplexing. The main characteristic of the model is that amplitude variations on one carrier wave are converted to phase variations on another carrier wave, i.e., the carriers interfere with each other through amplitude-to-phase conversion. For the case of two carriers, a new technique called interference focusing is proposed where each carrier achieves the capacity pre-log 1, thereby doubling the pre-log of 1/2 achieved by using conventional methods. The technique requires neither channel time variations nor global channel state information. Generalizations to more than two carriers are outlined.