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Updated: Nov 1, 2025
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Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping
Published on: March 20, 2017
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2048-QAM transmission at 15 GBd over 100 km using geometric constellation shaping
Optics Express
|June 22, 2021
Summary
This study enhanced achievable information rates (AIRs) in intradyne coherent systems using pilot-aided digital signal processing (DSP) and geometric constellation shaping (GS). The highest-order GS 2048 quadrature amplitude modulation (QAM) format achieved record data rates.
Area of Science:
- Optical Communications
- Digital Signal Processing
- Information Theory
Background:
- Standard intradyne coherent transmission systems face limitations in achievable information rates (AIRs).
- High-order modulation formats and advanced digital signal processing (DSP) are crucial for enhancing data transmission capacity.
Purpose of the Study:
- To investigate the combination of pilot-aided DSP and high-order geometric constellation shaping (GS) to increase AIRs.
- To demonstrate the highest-order GS format and its performance in intradyne coherent systems.
Main Methods:
- Experimental investigation of a pilot-aided DSP chain with high-order geometric constellation shaping.
- Utilizing geometrically-shaped (GS) 2048 quadrature amplitude modulation (QAM) at 15 GBd.
- Characterization of DSP, transceiver performance, and transmission modeling.
Main Results:
- Maximized AIR using GS 2048-QAM, reaching 18.0 b/4D-symbol (back-to-back) and 16.9 b/4D-symbol (100 km fiber).
- Demonstrated the highest-order GS format to date in standard intradyne systems.
- Achieved the highest AIR for systems using conventional optics and 8-bit electronics.
Conclusions:
- The combined pilot-aided DSP and GS approach significantly boosts AIR in intradyne coherent systems.
- This work sets a new benchmark for data rates in conventional optical and electronic systems.
- Further insights into impairments and improvements were provided through detailed characterization.
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