Spectrally efficient digital modulation method and apparatus
US4737969A · kind A · utility
116Cited by
3References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1987 |
| Grant date | Apr 12, 1988 |
| Priority date | — |
| Expiry date | Jan 28, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/3854
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are provided for generating a uniquely shaped prototype digital pulse which is transmitted with minimal frequency spectrum consumption and yet a relatively high bit rate. Such uniquely shaped digital pulse is stored in a memory included in a transmitter until transmission is desired, at which time a positive of the pulse is transmitted to correspond to a first logic level or the negative of the pulse is transmitted to correspond to a second logic level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.