Method and apparatus for code conversion of binary to multilevel signals
US4408189A · kind A · utility
60Cited by
5References
6Claims
0Family size
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Key dates
| Filing date | May 18, 1981 |
| Grant date | Oct 4, 1983 |
| Priority date | — |
| Expiry date | May 18, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/1496
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for converting a binary signal to one having quaternary-level symbols with no d-c component. To achieve this, the running digital sum is limited by selectively inverting words within each frame of (n) symbols. A separate (n+1)th symbol is added to each frame to indicate the selective inversion of the words, so that the correct polarity of the (n) symbols can be re-established.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.