Low-complexity optical phase noise suppression in CO-OFDM system using recursive principal components elimination.

Area of Science:

• Optical Communications
• Signal Processing
• Information Theory

Background:

• Coherent Optical Orthogonal Frequency-Division Multiplexing (CO-OFDM) systems are susceptible to optical phase noise (OPN).
• OPN causes signal distortion, limiting system performance and laser linewidth tolerance.
• Existing OPN suppression techniques often involve high computational complexity.

Purpose of the Study:

• To propose and theoretically derive a low-complexity optical phase noise suppression method.
• To reduce the computational complexity of OPN mitigation in CO-OFDM systems.
• To enhance the laser linewidth tolerance of CO-OFDM systems.

Main Methods:

• Recursive Principal Components Elimination (R-PCE) approach.
• Frequency domain principal components estimation and elimination.
• Decision-aided R-PCE (DA-R-PCE) for enhanced performance.
• Monte-Carlo simulations for feasibility demonstration.

Main Results:

• R-PCE significantly mitigates signal distortion caused by OPN.
• Computational complexity is drastically reduced compared to orthogonal basis expansion algorithms.
• R-PCE demonstrates superior laser linewidth tolerance, even with a small number of principal components (q=3).
• Optimal performance achieved with moderate q, suitable for hardware implementation.

Conclusions:

• R-PCE is a feasible and effective method for OPN suppression in CO-OFDM systems.
• The proposed method offers a significant improvement in laser linewidth tolerance.
• The low computational complexity makes R-PCE suitable for practical hardware implementation in CO-OFDM systems.