Simplified LDPC-assisted CNC algorithm for entropy-loaded discrete multi-tone in a 100G flexible-rate PON

Area of Science:

• Optical Communications
• Digital Signal Processing
• Telecommunications Engineering

Background:

• Passive Optical Networks (PONs) are crucial for high-speed data traffic in optical access networks.
• The capacity of PONs is limited by the optical power budget of the optical network unit.
• Discrete Multi-Tone (DMT) modulation faces challenges in peak-power constrained PONs.

Purpose of the Study:

• To demonstrate a flexible-rate PON capable of increasing network capacity.
• To improve the performance of DMT modulation in peak-power constrained PONs.
• To reduce computational complexity in digital signal processing for PONs.

Main Methods:

• Utilizing entropy-loaded clipping discrete multi-tone (DMT) modulation.
• Implementing a clipping operation combined with a simplified Low-Density Parity-Check (LDPC) assisted clipping-noise-cancellation (CNC) algorithm.
• Reducing the iteration number in the LDPC decoding's sum-product algorithm.

Main Results:

• The simplified LDPC-assisted CNC algorithm improved optical receiver sensitivity by approximately 1.8dB at the 20% soft-decision forward-error-correction limit.
• Achieved a wide-range data-rate adjustment from 12.5Gb/s to 100Gb/s.
• Demonstrated operation under varying optical power budgets from 40dB to 26dB.

Conclusions:

• The proposed flexible-rate PON effectively increases network capacity.
• The simplified CNC algorithm significantly enhances DMT performance in power-limited PONs with reduced complexity.
• This approach offers a scalable solution for future high-capacity optical access networks.