A simple design method using trellis search is proposed for good low-density parity-check (LDPC) codes with relatively low code rates. By applying a trellis search technique to the design of a pre-assigned part of the parity-check matrix that allows a simple encoding, we improve the distribution of cycles formed by the entries contained in the parity-check part of the parity-check matrix. In addition, we extend the proposed algorithm to a class of structured LDPC codes, which have been recently preferred in many practical applications. Simulation results show that the codes designed by the proposed method outperform those constructed by conventionally used greedy design algorithms.
Bibliographical noteFunding Information:
Paper approved by O. Milenkovic, the Editor for Coding Theory and Applications of the IEEE Communications Society. Manuscript received February 25, 2007; revised December 18, 2007 and June 26, 2008. Initial work of this paper was presented at the International Symposium on Information Theory and Its Applications (ISITA), Seoul, Korea, 2006. This research was supported by the Ministry of Knowledge Economy, Korea, under the ITRC (Information Technology Research Center) support program supervised by the IITA (Institute of Information Technology Advancement) (IITA-2008-C1090-0803-0002). S. H. Lee is with the Electronics and Telecommunications Research Institute, Daejeon, Korea (e-mail: firstname.lastname@example.org). K. S. Kim is with with the Department of Electrical and Computer Engineering, Yonsei University, Seoul, Korea (e-mail: email@example.com). Digital Object Identifier 10.1109/TCOMM.2009.07.070088 1Although the common definition of the echelon form does not require the existence of the two nonzero diagonal entries, it is used in this paper for simplicity.
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering