Low-density parity-check codes for 40-Gb/s optical transmission systems

Ivan B. Djordjevic, Sundararajan Sankaranarayanan, Shashi Kiran Chilappagari, Bane Vasic

Research output: Contribution to journalArticlepeer-review

82 Scopus citations


In this paper, we compare performance of three classes of forward error correction schemes for 40-Gb/s optical transmission systems. The first class is based on the concatenation of Reed-Solomon codes and this is employed in the state-of-the-art fiber-optics communication systems. The second class is the turbo product codes with Bose-Chaudhuri-Hocquenghen component codes. The application of these codes in optical communication systems was extensively studied by Sab and Lemarie, and Mizuochi et al. The third class is the low-density parity-check (LDPC) codes that have attracted much attention over the past decade. We present enhanced decoding algorithms for Turbo product codes and LDPC codes that use probability density function of output sequences instead of calculating initial likelihood ratios assuming (inaccurate) Gaussian or chi-square approximation. The analysis in this paper shows that the LDPC codes perform better than the other codes in the waterfall region at bit error rates as low as 10 -9. We also presented error floors results obtained by analyzing decoding failures of hard-decision iterative decoders.

Original languageEnglish (US)
Article number1668096
Pages (from-to)555-562
Number of pages8
JournalIEEE Journal on Selected Topics in Quantum Electronics
Issue number4
StatePublished - Jul 2006


  • Error floor
  • Low-density parity-check (LDPC) codes
  • Optical communications
  • Turbo product codes

ASJC Scopus subject areas

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


Dive into the research topics of 'Low-density parity-check codes for 40-Gb/s optical transmission systems'. Together they form a unique fingerprint.

Cite this