Advanced perturbation technique for digital backward propagation in WDM systems

Area of Science:

• Optical communication systems
• Signal processing

Background:

• Dense wavelength-division multiplexing (WDM) systems face challenges from inter-nonlinear effects and dispersion.
• Traditional perturbation techniques (TPT) for digital backward propagation (DBP) involve complex iterative calculations.

Purpose of the Study:

• To propose an improved digital backward propagation (DBP) method using an advanced perturbation technique (APT).
• To jointly compensate for inter-nonlinear effects and dispersion in WDM systems.
• To reduce computational complexity and improve accuracy compared to TPT.

Main Methods:

• Developed a non-iterative weighted concept to replace iterative calculations in analytical recursion expressions.
• Derived an analytical recursion expression for the output after backward propagation.
• Conducted numerical simulations across various transmission system parameters.

Main Results:

• The advanced perturbation technique (APT) relaxes step size requirements and reduces the oversampling factor at launch powers above -2 dBm.
• Demonstrated a significant reduction in computational complexity, estimated at a factor of seven compared to conventional DBP.
• Achieved joint compensation of inter-nonlinear effects and dispersion.

Conclusions:

• The proposed APT offers a more efficient and accurate approach for digital backward propagation in WDM systems.
• This technique is particularly beneficial for systems operating at higher launch powers.
• The non-iterative nature significantly simplifies the DBP process.