Secure 100 Gb/s IMDD Transmission Over 100 km SSMF Enabled by Quantum Noise Stream Cipher and Sparse RLS-Volterra Equalizer

Quan Yu,Lei Deng,Deming Liu,Xingxing Jiang,Linbojie Huang,Yudi Fu,Haiping Song,Mengfan Cheng,Di Li,Yang Wang

doi:10.1109/access.2020.2984330

Abstract

In this paper, we have experimentally demonstrated a secure 100 Gb/s intensity-modulation and direct-detection transmission over 100 km standard single-mode fiber (SSMF) based on quantum noise stream cipher (QNSC) for the first time. The original 4-level pulse-amplitude modulation (PAM4) data is mapped to M-level data sequence randomly, and quantum noise such as the generated amplified spontaneous emission noise and the shot noise in the channel can mask these adjacent signal levels. The legitimate receiver needs to distinguish not M-level encrypted data but 4-level data with the shared key. In our scheme, a calculated detection failure probability of 98.72% is achieved. Apparently, more quantum noise contributes to higher security but the worse signal to noise ratio. To balance algorithm complexity, transmission performance and security performance, a sparse $\ell _{1} $ regularization based on recursive least square (RLS) algorithm is proposed and firstly used in Volterra equalizer. To eliminate the power fading induced by fiber dispersion, a dual-drive Mach-Zehnder modulator is used to achieve single-sideband modulation, and no dispersion compensation is required. By these means, 100 Gb/s PAM4-QNSC signal transmission over 100 km SSMF with the bit error rate (BER) below the 7% overhead hard-decision forward error correction threshold of $3.8 \times 10^{-3}$ is achieved, and > 59% complexity reduction of Volterra equalizer is realized. Moreover, the measured BER of 150 Gb/s PAM8-QNSC signal transmission over 50 km SSMF could go below the 20% overhead soft-decision forward error correction threshold of $2.0\times 10^{-2}$ . The results validate that the proposed scheme is effective to realize low-cost, high-speed (> 100 Gb/s), and secure optical fiber transmission in the data center.

Highlights

The advent of the information age has accelerated the boom of the Internet, and the information traffic in the metro and short transmission networks is growing exponentially
The results show that the measured bit error rate (BER) value for both 100 Gb/s PAM4 signal transmission over 100 km standard single-mode fiber (SSMF) and 150 Gb/s PAM8 signal transmission over 25 km SSMF can go below the hard-decision forward error correction (HD-FEC) limit
The results show that the BER performance of the sparse recursive least square (RLS)-Volterra equalizer outperforms that of the sparse least mean square (LMS)-Volterra equalizer

Summary

Introduction

The advent of the information age has accelerated the boom of the Internet, and the information traffic in the metro and short transmission networks is growing exponentially. The growing demand for traffic capacity in the data center requires high-speed fiber-optic transmission [1]. The associate editor coordinating the review of this manuscript and approving it for publication was Rentao Gu. modulation and direct detection (IMDD) technique is preferred in the data center due to its low cost and low power consumption. The fiber-optic transmission is not safe enough as it commonly supposed because of more and more security threats [5]. Establishing low cost, high-speed and secure fiber communication in the data center is an urgent demand

Methods

Results

Conclusion