Patent · US Expired

Decoder for cross interleaved error correcting encoded data

US5412667A · kind A · utility

25Cited by
4References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 8, 1993
Grant dateMay 2, 1995
Priority date
Expiry dateJul 8, 2013

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03M13/151
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

An improved method for processing a sector of data read from a CD-ROM which has been encoded using a cross-interleaved Reed Solomon (CIRS) code is time linear in the number of errors in the sector. The improved method iteratively processes the data values from the sector, which appear in each of the sets of cross-interleaved sequences, through an error detection/correction algorithm. In the first pass, a syndrome is generated for each sequence in each set. If the syndrome indicates that the sequence either contains no errors or an undetectable number of errors, the sequence is marked as being error-free. If a sequence contains a correctable error, the error is corrected and the sequence is marked as being error-free. If the syndrome indicates that the sequence contains a number of errors which may be detected but not corrected the sequence is marked as containing errors. After the first pass the improved method only calculates an error syndrome for the sequences which are marked as containing errors. The sequences in this subset are those which are determined by the method to possibly contain an error. If an error is corrected in a sequence from one of the sets during any of the pa…

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