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Updated: Oct 17, 2025
07:45
Quasi-light Storage for Optical Data Packets
Published on: February 6, 2014
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Subcarrier-pairing entropy loading for digital subcarrier-multiplexing systems with colored-SNR distributions
Optics Express
|October 7, 2021
Summary
A new subcarrier-pairing entropy loading (SubP-EL) scheme efficiently optimizes digital subcarrier-multiplexing systems. This method significantly reduces computational complexity while maintaining near-optimal performance in optical fiber transmissions.
Area of Science:
- Digital Communications
- Optical Networks
- Information Theory
Background:
- Digital subcarrier-multiplexing (SCM) systems face challenges with colored signal-to-noise ratio (SNR) distributions.
- Optimizing data loading across subcarriers is crucial for maximizing system performance.
Purpose of the Study:
- To propose a low-complexity entropy loading scheme for SCM systems.
- To evaluate the performance and complexity of the proposed scheme against existing methods.
Main Methods:
- A subcarrier-pairing entropy loading (SubP-EL) algorithm is developed.
- The scheme iteratively optimizes subcarrier entropy in pairs under a target entropy constraint.
- Performance is validated through simulations and experimental fiber transmissions.
Main Results:
- SubP-EL achieves near-optimal performance comparable to brute-force methods.
- Significant complexity reduction is observed; for an 8-subcarrier system, complexity is reduced by factors of 764, 95, and 13 for different entropy granularities.
- Experimental 345 km fiber transmissions show an average NGMI gain of 0.0286 over systems without entropy loading.
Conclusions:
- The SubP-EL scheme offers an efficient and practical solution for entropy loading in SCM systems.
- It provides a substantial reduction in computational complexity without sacrificing significant performance.
- The method demonstrates practical viability in optical communication systems.
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