Intra-symbol frequency-domain averaging based channel estimation for coherent optical OFDM

Area of Science:

• Optical Communications
• Signal Processing
• Photonics

Background:

• Coherent optical orthogonal frequency-division multiplexing (CO-OFDM) is a key technology for high-capacity optical transport systems.
• Accurate channel estimation is crucial for compensating impairments in CO-OFDM systems.
• Existing channel estimation methods may struggle with robustness against diverse transmission impairments.

Purpose of the Study:

• To propose and evaluate an efficient channel estimation method for CO-OFDM systems.
• To systematically assess the robustness of the proposed method against major optical transmission impairments.
• To validate the performance of the method in a realistic high-speed optical transport scenario.

Main Methods:

• Development of an intra-symbol frequency-domain averaging (ISFA) based channel estimation algorithm.
• Numerical simulations of a 112-Gb/s polarization-division multiplexed (PDM) CO-OFDM signal.
• Systematic analysis of the method's performance under optical noise, chromatic dispersion (CD), polarization-mode dispersion (PMD), polarization-dependent loss (PDL), and fiber nonlinearity.

Main Results:

• The proposed ISFA-based channel estimation method is computationally efficient.
• The method demonstrates significant robustness against optical noise, CD, PMD, PDL, and fiber nonlinearity.
• Effective channel compensation is achieved following the ISFA-based estimation.

Conclusions:

• The ISFA-based channel estimation offers a robust solution for CO-OFDM systems.
• This method is well-suited for mitigating impairments in typical optical transport networks.
• The findings support the practical deployment of advanced CO-OFDM systems.