Signalling transition control in a modulated-signal communications system
US5321799A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 17, 1992 |
| Grant date | Jun 14, 1994 |
| Priority date | — |
| Expiry date | Apr 17, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/0008
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A signal transition control system for use in a modulated-signal communication system having a plurality of predefined signal states each representing a digital data symbol, enables a transition from one signal state to a next signal state to be executed in a smooth, bandwidth-efficient manner. The system includes circuitry for receiving a stream of data symbols and storing in succession consecutive pairs of the data symbols, each of the pairs including a last data symbol and a next data symbol, for producing data describing a vector in signal space from the last data symbol to the next data symbol, for storing data representative of a desired shape of a transition from the last data symbol to the next data symbol, means for sequentially stepping through the data representative of the desired shape, and for producing data representing a transition from the last data symbol to the next data symbol, the transition having the desired shape. The system is used to particular advantage in a number-controlled modulated oscillator that generates a signal having a numerically controlled frequency, a numerically controlled phase, a programmable shape, and a numerically controlled amplitude.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.