A Soft-Aided Staircase Decoder Using Three-Level Channel Reliabilities

Research output: Contribution to journalArticleAcademicpeer-review


The soft-aided bit-marking (SABM) algorithm is based on the idea of marking bits as highly reliable bits (HRBs), highly unreliable bits (HUBs), and uncertain bits to improve the performance of hard-decision (HD) decoders. The HRBs and HUBs are used to assist the HD decoders to prevent miscorrections and to decode those originally uncorrectable cases via bit flipping (BF), respectively. In this paper, an improved SABM algorithm (called iSABM) is proposed for staircase codes (SCCs). Similar to the SABM, iSABM marks bits with the help of channel reliabilities, i.e., using the absolute values of the log-likelihood ratios. The improvements offered by iSABM include: (i) HUBs being classified using a reliability threshold, (ii) BF randomly selecting HUBs, and (iii) soft-aided decoding over multiple SCC blocks. The decoding complexity of iSABM is comparable of that of SABM. This is due to the fact that on the one hand no sorting is required (lower complexity) because of the use of a threshold for HUBs, while on the other hand multiple SCC blocks use soft information (higher complexity). The gains achieved by iSABM are up to 0.53 dB with respect to SABM and up to 0.91 dB with respect to standard decoding of SCCs at a bit error rate 10<sup>-6</sup>. Furthermore, it is shown that using 1-bit reliability marking, i.e., only having HRBs and HUBs, only causes a gain penalty of up to 0.25 dB with a significantly reduced memory requirement.

Original languageEnglish
JournalJournal of Lightwave Technology
Issue numberX
Publication statusAccepted/In press - 2021

Bibliographical note

Publisher Copyright:


  • Complexity theory
  • Decoding
  • Forward error correction
  • Gain
  • Iterative decoding
  • Log-likelihood ratios
  • Optical fiber communications
  • Quantization
  • Quantization (signal)
  • Reliability
  • Staircase codes
  • Standards


Dive into the research topics of 'A Soft-Aided Staircase Decoder Using Three-Level Channel Reliabilities'. Together they form a unique fingerprint.

Cite this