Data modulation interface
US4771440A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 3, 1986 |
| Grant date | Sep 13, 1988 |
| Priority date | — |
| Expiry date | Dec 3, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4902
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A data modulation interface is provided for serial data transmission. A biphase signal is encoded with the binary bits of a parallel data word. The bits of the parallel data word are examined to determine whether there are more one bits or zero bits in the word. A polarity bit is provided in addition to the other bits to indicate which bit-state occurred most often. The biphase signal is modulated to create different time intervals between phase reversals with one time interval corresponding to a bit-state of one and another time interval corresponding to a bit-state of zero. The shortest time interval is assigned to correspond to the bit-state occurring most often in the word so that the total time required to transmit each word is minimized. A time interval can be assigned to a sync signal transmitted after each parallel data word. A time interval can also be assigned to correspond to plural bit combinations so they can be represented by a single phase interval and transmitted quickly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.