J4 ›› 2011, Vol. 38 ›› Issue (2): 8-12+196.doi: 10.3969/j.issn.1001-2400.2011.02.002

• Original Articles • Previous Articles     Next Articles

Simplified decoding algorithm for LDPC over GF(q)

HU Shukai;WANG Xinmei   

  1. (State Key Lab. of Integrated Service Networks, Xidian Univ., Xi'an  710071, China)
  • Received:2010-04-12 Online:2011-04-20 Published:2011-05-26
  • Contact: HU Shukai E-mail:hushukai@sohu.com

Abstract:

A simple, yet effective decoding algorithm for LDPC (low-density parity-check) codes over GF(q) is presented. By taking advantages of the first-term Taylor's series expansion to approximate the correction term of the Jacobian logarithm used in LLR-SPA(log-likelihood ratio sum-product algorithm), we propose an algorithm which significantly simplifies the check node update computation of the optimal LLR-SPA. Compared to the offset min-sum algorithm, the proposed algorithm achieves a gain of about 0.2dB at the BER of 10-4. Moreover, unlike the offset min-sum algorithm, parameters of this algorithm are independent of the order of the Galois Filed.

Key words: nonbinary LDPC codes, sum-product algorithm, min-sum algorithm, iterative decoding