Abstract
Fiber nonlinearity imposes limitations on the transmission distances in optical fiber networks. Fiber nonlinearity compensation (NLC) becomes essential for extending the transmission reach; however, conventional methods like digital backpropagation (DBP) experience challenges related to the intricacies of computational demands. To mitigate the fiber nonlinearity cost-effectively, subcarrier multiplexing (SCM) emerges as a promising solution compared to single-carrier systems. However, the SCM performance is limited by nonlinear effects such as self-subcarrier nonlinearity (SSN) and cross-subcarrier nonlinearity (CSN). In previous studies, a combination of SCM with DBP, named SCM-DBP, has been employed to address these issues. Concurrently, deep learning-assisted NLC, for example, learned DBP (LDBP), has shown promise in enhancing performance and reducing complexity. In this paper, we aim to apply learning to the SCM-DBP by holistically combining the principles of the SCM-DBP and LDBP approaches, denoted as SCM-LDBP, to mitigate SSN and CSN cost-effectively. To investigate the efficacy of our proposed SCM-LDBP technique, we carry out numerical simulations for both a contemporary 32 Gbaud and a strategic 120 Gbaud SCM transmission system over a 1600km optical fiber link. With only two interfering subcarriers in the back-propagation routine, our proposed SCM-LDBP demonstrates a 0.3dB Q factor improvement and a 31.7% complexity reduction in the 32 Gbaud system when compared to the SCM-DBP. Similarly, in the 120 Gbaud system, the proposed SCM-LDBP demonstrates a 0.2dB Q factor improvement and a 37.8% reduction in complexity over the SCM-DBP technique.
Original language | English |
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Pages (from-to) | 8162-8172 |
Number of pages | 11 |
Journal | Journal of Lightwave Technology |
Volume | 42 |
Issue number | 23 |
Early online date | 12 Jul 2024 |
DOIs | |
Publication status | Published (in print/issue) - 1 Dec 2024 |
Bibliographical note
Publisher Copyright:© 2024 IEEE.
Keywords
- Complexity theory
- Mathematical models
- Optical fiber networks
- Optical fiber polarization
- Symbols
- Optical fiber filters
- Q-factor
- Coherent communications
- machine learning
- nonlinearity compensation
- optical fiber communications
- subcarrier multiplexing