AMI-Assisted High-Capacity DWDM Optical Transmission with MIMO-OFDM for Future Networks

Abstract

Line coding plays a critical role in determining the performance and reliability of digital communication systems. This paper proposes a novel high-speed optical transmission method that employs Alternate Mark Inversion (AMI) line coding in a DWDM system integrated with an OFDM modulator and demonstrates its superior performance compared to conventional line coding schemes such as Non-Return-to-Zero (NRZ), Return-to-Zero (RZ), and Duo Binary Modulation class-1 (DBM1). The proposed AMI-DWDM-MIMO-OFDM system is evaluated over link lengths ranging from 50 to 150 km, with varying input power, link length, and data rate, using OptiSystem and MATLAB simulations. Owing to its DC-free bipolar signaling, AMI significantly suppresses baseline wander, intersymbol interference, and low-frequency power components. Results show BER improvements of 10−³ over NRZ and 10−3 over RZ and DBM1, along with a 9–12 dB OSNR and 18-25% wider eye opening even under challenging long-haul conditions. The scheme enables secure, low-latency transmission suitable for future 5G/6G optical backbone networks. These results show that MIMO-OFDM combined with AMI-based DWDM has the potential to be an acceptable option for next-generation optical backbone networks that demand resilience, efficiency, and robust physical-layer security.