Multi-phase and multi-amplitude level modulator and modulation and demodulation methods
US3983485A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 28, 1975 |
| Grant date | Sep 28, 1976 |
| Priority date | — |
| Expiry date | Feb 28, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/361
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A multi-phase, multi-amplitude level modulation method, and modulator, is provided which produces a three-level, ten-phase modulated carrier. The carrier is modulated in three amplitude levels, viz., off, intermediate and high and in ten phase positions, to produce sixteen signal states, one state corresponding to the carrier being off, five intermediate amplitude level states having five equally spaced phase positions, and ten high amplitude level states having ten equally spaced phase positions. A number of different four digit binary coding schemes for the sixteen signal states are disclosed together with other different coding and modulation techniques.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.