Nonlinear Digital Back Propagation compensator for coherent optical OFDM based on factorizing the Volterra Series...

Area of Science:

• Optical Communications
• Digital Signal Processing
• Nonlinear Optics

Background:

• Digital back-propagation (DBP) is crucial for mitigating nonlinear impairments in coherent optical OFDM systems.
• Existing Volterra Series Transfer Function (VSTF) based nonlinear compensation methods face high computational complexity.
• There is a need for efficient and accurate nonlinear compensation techniques to enhance receiver performance.

Purpose of the Study:

• To introduce an efficient and accurate nonlinear compensator (NLC) for DBP in coherent optical OFDM receivers.
• To reduce the computational complexity of nonlinear compensation based on VSTF.
• To improve the nonlinear tolerance of optical communication links.

Main Methods:

• A novel factorization procedure for the Volterra Series Transfer Function (VSTF) is proposed.
• The proposed method reduces the nonlinear compensation complexity from O(N^2) to 28 + 6logN.
• The NLC system was analyzed and simulated for performance evaluation.

Main Results:

• The proposed NLC system demonstrates superior performance compared to previous VSTF-based nonlinear compensation methods.
• The new method achieves an improved nonlinear tolerance of approximately 2 dB for the analyzed link.
• The computational complexity of the new method is 52% higher than a recent VSTF-based method, but offers significant performance gains.

Conclusions:

• The developed NLC provides an efficient and accurate solution for nonlinear compensation in DBP.
• This approach effectively enhances nonlinear tolerance in coherent optical OFDM systems.
• The trade-off between computational complexity and performance improvement is favorable for practical applications.