Four-dimensional optical multiband-OFDM for beyond 1.4 Tb/s serial optical transmission

Area of Science:

• Optical communications engineering
• Signal processing
• Information theory

Background:

• Optical Orthogonal Frequency Division Multiplexing (OFDM) is crucial for high-speed optical transport.
• Chromatic dispersion, Polarization Mode Dispersion (PMD), and Polarization Dependent Loss (PDL) degrade optical signal quality.
• Existing optical OFDM schemes face limitations in OSNR sensitivity.

Purpose of the Study:

• To propose a novel four-dimensional (4D) coded multiband-OFDM scheme.
• To achieve data rates beyond 1.4 Tb/s for serial optical transport.
• To enhance the OSNR sensitivity and robustness against impairments of optical OFDM.

Main Methods:

• Organizing N-dimensional (ND) signal constellation points into a signal matrix.
• Utilizing 2D-inverse Fast Fourier Transform (FFT) for modulation and 2D-FFT for demodulation.
• Exploiting orthogonal polarizations in conjunction with multidimensional signal constellations.

Main Results:

• The proposed 4D-OFDM scheme effectively mitigates chromatic dispersion, PMD, and PDL.
• Significant improvements in OSNR sensitivity compared to conventional optical OFDM were observed.
• Performance gains ranged from 1.79 dB (16-4D-OFDM) to 4.53 dB (128-4D-OFDM) over polarization-multiplexed QAM.

Conclusions:

• The 4D coded multiband-OFDM scheme offers a viable solution for ultra-high-speed optical transport.
• This approach leverages multidimensional signal constellations to overcome limitations of existing optical OFDM systems.
• The scheme demonstrates superior performance in terms of OSNR sensitivity and impairment mitigation.