FPGA implementation of rate-adaptive spatially coupled LDPC codes suitable for optical communications

Area of Science:

• Digital Communications
• Error Correction Coding

Background:

• Forward Error Correction (FEC) is crucial for reliable data transmission.
• Low-Density Parity-Check (LDPC) codes offer near-Shannon limit performance.
• Spatially Coupled (SC) LDPC codes enhance performance but require efficient implementation.

Purpose of the Study:

• To propose a unified Field-Programmable Gate Array (FPGA) structure for rate-adaptive FEC.
• To enable on-the-fly rate adaptation for spatially coupled (SC) LDPC codes derived from quasi-cyclic (QC) LDPC codes.
• To demonstrate the feasibility and benefits of the unified decoder structure.

Main Methods:

• Design of a unified decoder architecture for SC-LDPC codes.
• Integration of a controller for on-the-fly rate adaptation.
• FPGA-based emulation for performance evaluation.

Main Results:

• The unified structure supports rate adaptation for QC-LDPC derived SC codes.
• FPGA emulation confirms SC codes provide larger coding gain at comparable complexity.
• The implemented decoder is versatile for various template QC-LDPC codes.

Conclusions:

• The proposed unified FPGA structure effectively implements rate-adaptive FEC using SC-LDPC codes.
• This approach enhances coding gain and offers flexibility for different code rates.
• The design facilitates efficient and reliable data transmission in digital systems.