Reduced-complexity decoding of Q-ary LDPC codes for magnetic recording

• Published in: IEEE transactions on magnetics Vol. 39; no. 2; pp. 1081 - 1087
• Main Authors: Hongxin Song, Cruz, J.R.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2003; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Additive white noise; Algorithms; Applied sciences; AWGN channels; Bursting; Channels; Decoding; Electronics; Exact sciences and technology; Fading; Gaussian; Gaussian noise; Impairment; Iterative algorithms; Iterative decoding; Magnetic and optical mass memories; Magnetic recording; Magnetism; Matrices; Other magnetic recording and storage devices (including tapes, disks, and drums); Parity check codes; Reed-Solomon codes; Storage and reproduction of information; Thermal degradation; Reed Solomon code; AWGN; Magnetic recording noise; low-density parity-check (LDPC) codes; Coding; Theoretical study; Iterative decoding; Magnetic recording; Belief propagation
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2003.808600

Binary low-density parity-check (LDPC) codes perform very well on magnetic recording channels (MRCs) with additive white Gaussian noise (AWGN). However, an MRC is subject to other impairments, such as media defects and thermal asperities. Binary LDPC codes may not be able to cope with these impairments without the help of a Reed-Solomon code. A better form of coding may be Q-ary LDPC codes, which have been shown to outperform binary LDPC codes and Reed-Solomon codes on the AWGN channel. In this paper, we report on our investigation of Q-ary LDPC coded MRCs, both with AWGN and with burst impairments, and we present a new reduced-complexity decoding algorithm for Q-ary LDPC codes. We show that Q-ary LDPC codes outperform binary LDPC codes in the presence of burst impairments.