Optical disk apparatus permitting high-precision Viterbi decoding
US6920100B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 2002 |
| Grant date | Jul 19, 2005 |
| Priority date | — |
| Expiry date | Jan 10, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/6343
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The optical disk apparatus is provided with a Viterbi decoder and an expected value correction circuit. The branch metric operation unit calculates first, second and third errors between sampling data and expected values, and outputs them to the expected value correction circuit. The expected value correction circuit extracts the sampling data in a region where its variation is small based on the first, second and third errors, calculates the average values of the extracted sampling data to correct the first, second and third expected values, and outputs the corrected expected values to the branch metric operation unit. The Viterbi decoder performs Viterbi decoding of the sampling data based on the first, second and third corrected expected values. Thus, high-precision Viterbi decoding is permitted even if the amplitude value of the reproduction signal varies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.