Method and apparatus for multilevel encoding for a local area network
US5280500A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1991 |
| Grant date | Jan 18, 1994 |
| Priority date | — |
| Expiry date | Oct 10, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M5/20
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A multilevel encoding scheme for transmitted data that encodes data in a multilevel code wherein the amplitude of any transition is always exactly one level during any time interval. A single-level transition between any two adjacent levels during a time interval represents a logical "1"; no transition during a time interval represents a logical "0". In a specific embodiment, modulation is limited to three defined amplitude levels equally space in amplitude and encoding is according to a three-level code. A four-bit to five-bit encoding scheme may be used to distribute bits for minimizing d.c. offset. The input data is preferably further scrambled to minimize aberrations in the emissions spectrum of signal carried over unshielded media.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.