A 9.52 dB NCG FEC scheme and 164 bits/cycle low-complexity product decoder architecture

TL;DR

This paper introduces a novel product code-based FEC scheme with post-processing that achieves high net coding gains and low complexity, suitable for high-speed optical communication systems.

Contribution

A new FEC scheme based on product codes with post-processing, achieving high NCG and low complexity, tested on FPGA and CMOS.

Findings

Achieves 9.52 dB NCG at BER 10^{-15}

Reaches 9.96 dB NCG at BER 10^{-18}

Decodes at 164 bits/cycle with 100 Gb/s throughput

Abstract

Powerful Forward Error Correction (FEC) schemes are used in optical communications to achieve bit-error rates below $10^{-15}$. These FECs follow one of two approaches: concatenation of simpler hard-decision codes or usage of inherently powerful soft-decision codes. The first approach yields lower Net Coding Gains (NCGs), but can usually work at higher code rates and have lower complexity decoders. In this work, we propose a novel FEC scheme based on a product code and a post-processing technique. It can achieve an NCG of 9.52~dB at a BER of $10^{-15}$ and 9.96~dB at a BER of $10^{-18}$, an error-correction performance that sits between that of current hard-decision and soft-decision FECs. A decoder architecture is designed, tested on FPGA and synthesized in 65 nm CMOS technology: its 164 bits/cycle worst-case information throughput can reach 100 Gb/s at the achieved frequency of 609~MHz. Its complexity is shown to be lower than that of hard-decision decoders in literature, and an order of magnitude lower than the estimated complexity of soft-decision decoders.