BER performance due to irregularity of row-weight distribution of the parity-check matrix in irregular LDPC codes for 10-Gb/s optical signals

Jinhyun Youn, Hodeok Jang, Kyoungsoo Kim, Jichai Jeong

Research output: Contribution to journalArticle

8 Citations (Scopus)


Forward-error correction (FEC) coding is theoretically investigated to improve bit-error-rate (BER) performance in a 10-Gb/s optical transmission system using randomly irregular low-density parity-check (LDPC) codes, regular LDPC codes, and the Reed-Solomon (RS) (255,239) code as a comparison. The irregular LDPC codes has different row-weight variances of a parity-check matrix from 10.9 to 18.8 and a row-weight mean of 60. Simulation is carried out under various conditions including the impairment factors such as dispersion, polarization-mode dispersion (PMD), and fiber nonlinearities. Results suggest that the irregular LDPC code with a low row-weight variance (= 10.9) generally has better performance for the most impairment factors except for the factor of dispersion. On the other hand, for the factor of dispersion, the irregular LDPC code performs better with a high row-weight variance (= 18.8). A specific LDPC code can overcome the impairment limits in a deployed link.

Original languageEnglish
Pages (from-to)2673-2680
Number of pages8
JournalJournal of Lightwave Technology
Issue number9
Publication statusPublished - 2005 Sep 1



  • Belief-propagation algorithm
  • Block codes
  • Forward-error correction (FEC)
  • Graph girth
  • Iterative decoding
  • Low-density parity-check (LDPC) codes
  • Optical communications
  • Sum-product algorithm (SPA)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Atomic and Molecular Physics, and Optics

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