EFM/DVD demodulator
US6177892A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 31, 1998 |
| Grant date | Jan 23, 2001 |
| Priority date | — |
| Expiry date | Dec 31, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/8042
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A technique to demodulate digital data streamed from a recording medium by periodically hashing m-bits of data to create an index to a look up table and a code word identifier. The look up table includes the modulation pattern, which has a plurality of m-bit data entries, mapped into a plurality of n-bit data clusters, with each of the plurality of data clusters including a sub-portion of one of the plurality of m-bit data entries and a cluster identifier, with each of the plurality of data clusters differing from the remaining data clusters, with n being less than mn. The index and code word identifier is determined from a sub-portion of the m-bits of data, which are then both compared with a sub-group of the plurality of data clusters. Upon finding a match between one of the data clusters of the subgroup and both the index and the code word identifier, a signal is generated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.