Method for decoding double-encoding codes and apparatus using the same
US4653052A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 1, 1985 |
| Grant date | Mar 24, 1987 |
| Priority date | — |
| Expiry date | Jul 1, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/29
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a method and an apparatus for decoding double-encoding codes in which the information to be decoded comprises a first data and a second data. The operation for decoding double-encoding codes is achieved through two stages. A decoder of the first stage checks the first data, and when an error is found in the first data, all symbols of the first data are assumed to be wrong. The first-stage decoder then adds an erasure flag to all symbols to generate erasure symbols. As a result, these erasure symbols include the symbols which are actually erroneous and those which are correct. A decoder of the second stage is used to perform an error correction on the second data. For this purpose, the second-stage decoder detects the number of erasure symbols which are contained in the second data and which are actually erroneous. If the number of actually erroneous symbols does not exceed the maximum number of correctable symbols which can be corrected by the decoder of the second stage, the error correction is effected; otherwise, the decoder detects an error without conducting the error correction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.