A study on iterative decoding with LLR modulator by parity check information in SMR system

M. Nishikawa, Y. Nakamura, H. Osawa, Y. Okamoto, Y. Kanai, H. Muraoka

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


In recent years, shingled magnetic recording (SMR) has attracted attention as a new recording system of the hard disk drives. Although SMR can realize narrow track by overwriting data track like tile roofing, it has remarkable performance deterioration due to the influence of inter-track interference. Therefore, the performance improvement of the low-density parity-check (LDPC) coding and iterative decoding system using the sum-product decoding is required. In this paper, we propose the LDPC encoding and iterative decoding system with the log-likelihood ratio modulator and show the error floor is eliminated and improvement of signal-to-noise ratio to achieve the error free is obtained in the SMR under an areal recording density of 4 Tbits/in2 specification for the channel bit sequence coded by run-length limited and LDPC encoders by computer simulation. Therefore, the channel bit is composed bit about five magnetic grains.

Original languageEnglish
Article number8369398
JournalIEEE Transactions on Magnetics
Issue number11
Publication statusPublished - 2018 Nov
Externally publishedYes


  • Log-likelihood ratio (LLR)
  • parity check information
  • shingled magnetic recording (SMR)

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


Dive into the research topics of 'A study on iterative decoding with LLR modulator by parity check information in SMR system'. Together they form a unique fingerprint.

Cite this