Coherent optical DFT-spread OFDM transmission using orthogonal band multiplexing

Area of Science:

• Optical Communications
• Signal Processing

Background:

• Coherent optical OFDM (CO-OFDM) with orthogonal band multiplexing offers a scalable solution for ultra-high-speed data rates.
• Fiber nonlinearity poses a challenge for long-haul optical transmission systems.

Purpose of the Study:

• To investigate the performance of Digital Fourier Transform Spread CO-OFDM (DFT-S OFDM) in a band-multiplexed transmission system.
• To evaluate DFT-S OFDM's effectiveness in mitigating fiber nonlinearity and reducing peak-to-average power ratio (PAPR).

Main Methods:

• Illustration of the DFT-S OFDM principle.
• Experimental evaluation of coherent optical DFT-S OFDM in a band-multiplexed system.
• Comparison with conventional clipping methods for PAPR reduction.

Main Results:

• DFT-S OFDM effectively reduces the PAPR compared to conventional clipping methods.
• Reduced PAPR is achieved without interference from neighboring bands.
• Successful demonstration of 1.45 Tb/s DFT-S OFDM transmission over 480 km of standard single-mode fiber (SSMF).

Conclusions:

• DFT-S OFDM is a viable technique for mitigating fiber nonlinearity in long-haul optical communication systems.
• The reduced PAPR offered by DFT-S OFDM enables higher data rates and transmission distances.