A low-weight trellis-based iterative soft-decision decoding algorithm for binary linear block codes

Takuya Koumoto, Toyoo Takata, Tadao Kasami, Shu Lin

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


This paper presents a new low-weight trellis-based softdecision iterative decoding algorithm for binary linear block codes. The algorithm is devised based on a set of optimality conditions and the generation of a sequence of candidate codewords for an optimality test. The initial candidate codeword is generated by a simple decoding method. The subsequent candidate codewords, if needed, are generated by a chain of low-weight trellis searches, one at a time. Each search is conducted through a low-weight trellis diagram centered around the latest candidate codeword and results in an improvement over the previous candidate codewords that have been already tested. This improvement is then used as the next candidate codeword for a test of optimality. The decoding iteration stops whenever a candidate codeword is found to satisfy a sufficient condition on optimality or the latest low-weight trellis search results in a repetition of a previously generated candidate codeword. A divide-and-conquer technique is also presented for codes that are not spanned by their minimum-weight codewords. The proposed decoding algorithm has been applied to some well-known codes of lengths 48, 64, and 128. Simulation results show that the proposed algorithm achieves either practically optimal error performance for the example codes of length 48 and 64 or near optimal error performance for the (128, 29, 32) RM code with a significant reduction in computational decoding complexity.

Original languageEnglish
Pages (from-to)731-741
Number of pages11
JournalIEEE Transactions on Information Theory
Issue number2
Publication statusPublished - 1999
Externally publishedYes


  • Iterative decoding
  • Low-weight subtrellis
  • Optimality

ASJC Scopus subject areas

  • Information Systems
  • Computer Science Applications
  • Library and Information Sciences


Dive into the research topics of 'A low-weight trellis-based iterative soft-decision decoding algorithm for binary linear block codes'. Together they form a unique fingerprint.

Cite this