Achievable Physical-Layer Secrecy in Multi-Mode Fiber Channels using Artificial Noise

TL;DR

This paper proposes a scheme using artificial noise to enhance physical-layer secrecy in multi-mode fiber channels, demonstrating positive secrecy rates through real measurements and outperforming standard methods.

Contribution

Introduces an artificial noise-based transmission scheme and optimization algorithm for secure multi-mode fiber communication with real-world validation.

Findings

Positive average secrecy rates achieved with artificial noise

Gain over standard precoding and power allocation schemes

Validated on actual multi-mode fiber measurements

Abstract

Reliable and secure communication is an important aspect of modern fiber optic communication. In this work we consider a multi-mode fiber (MMF) channel wiretapped by an eavesdropper. We assume the transmitter knows the legitimate channel, but statistical knowledge of the eavesdropper's channel only. We propose a transmission scheme with artificial noise (AN) for such a channel. In particular, we formulate the corresponding optimization problem which aims to maximize the average secrecy rate and develop an algorithm to solve it. We apply this algorithm to actual measured MMF channels. As real fiber measurements show, for a 55 mode MMF we can achieve positive average secrecy rates with the proper use of AN. Furthermore, the gain compared to standard precoding and power allocation schemes is illustrated.