Low overhead and nonlinear-tolerant adaptive zero-guard-interval CO-OFDM

Area of Science:

• Optical Communications
• Signal Processing
• Photonics

Background:

• Coherent optical orthogonal frequency-division multiplexing (CO-OFDM) is crucial for high-speed optical transmission.
• Zero-guard-interval (ZGI) techniques reduce overhead but are sensitive to transmission impairments.
• Accurate channel estimation (CE) is vital for mitigating these impairments.

Purpose of the Study:

• To propose and evaluate an adaptive channel estimation (CE) method for ZGI CO-OFDM systems.
• To assess the method's performance and robustness in a practical experimental setup.
• To analyze the impact of various transmission impairments on the proposed CE-aided system.

Main Methods:

• Development of an adaptive channel estimation algorithm tailored for ZGI CO-OFDM.
• Experimental demonstration using a 28 Gbaud polarization-division multiplexed ZGI CO-OFDM system.
• Systematic investigation of robustness against residual chromatic dispersion, polarization-mode dispersion, SOP rotation, SFO, and fiber nonlinearity.

Main Results:

• The adaptive CE method achieved high performance with only 1% OFDM processing overhead.
• Experimental and numerical results confirmed the system's robustness against multiple transmission impairments.
• The proposed method effectively mitigates distortions in high-speed optical fiber transmission.

Conclusions:

• The adaptive CE-aided ZGI CO-OFDM system offers a robust solution for future optical networks.
• This approach enhances the reliability of high-baud-rate optical communication systems.
• The method provides a practical means to overcome challenges in optical fiber transmission.