Evaluation of four-dimensional nonbinary LDPC-coded modulation for next-generation long-haul optical transport...

Area of Science:

• Optical Communications
• Information Theory
• Digital Signal Processing

Background:

• Advanced coherent optical communication technologies are crucial for future optical transport networks.
• Previous studies on 4D-NB-LDPC-CM primarily focused on amplified spontaneous emission (ASE) noise.
• Realistic optical fiber transmission involves multiple impairments including dispersion, nonlinearities, and noise.

Purpose of the Study:

• To investigate the feasibility of four-dimensional (4D) nonbinary LDPC-coded modulation (4D-NB-LDPC-CM) for long-haul optical transmission.
• To evaluate the performance of 4D-NB-LDPC-CM in a realistic optical fiber environment considering multiple impairments.
• To compare 4D-NB-LDPC-CM with conventional 2D modulation formats and 4D bit-interleaved LDPC-coded modulation (4D-BI-LDPC-CM).

Main Methods:

• Utilizing advanced coherent optical communication technologies.
• Simulating optical fiber transmission incorporating dispersion effects, nonlinear phase noise, Kerr nonlinearities, stimulated Raman scattering, and ASE noise.
• Comparing the performance of 4D-NB-LDPC-CM with PDM-2D and 4D-BI-LDPC-CM schemes.

Main Results:

• 4D modulation formats offer advantages over 2D formats in LDPC-coded modulation.
• 4D-NB-LDPC-CM schemes significantly outperform conventional PDM-2D counterparts.
• 4D-NB-LDPC-CM schemes show superior performance compared to 4D-BI-LDPC-CM schemes.
• The transmission reach improvement of 4D-NB-LDPC-CM over 4D-BI-LDPC-CM increases with constellation size and spectral efficiency.

Conclusions:

• 4D-NB-LDPC-CM is a highly effective scheme for long-haul optical transmission.
• The proposed scheme demonstrates significant advantages over existing modulation formats in realistic optical environments.
• 4D-NB-LDPC-CM is a promising candidate for next-generation optical networks, offering enhanced performance and reach.