Patent · US Expired

Rate 24/25 modulation code for PRML recording channels

US5757294A · kind A · utility

41Cited by
7References
21Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 31, 1996
Grant dateMay 26, 1998
Priority date
Expiry dateDec 31, 2016

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B2020/1449
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

Rate 24/25 modulation encoding methods and apparatus improve efficiency in a PRML magnetic recording channel. The rate 24/25 code word uses rate 8/9 RLL encoding of one byte of user data, combined with interleaved unencoded bytes to achieve improved code rates with reasonable global run length constraint. Use of the the rate 8/9 RLL (0,3) subcode results in a rate 24/25 RLL (0,11) code, while a rate 8/9 (0,6/5) subcode results in a rate 24/25 RLL (0,14/13) code.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.