Method and system for providing precise multi-function modulation
US4812786A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1987 |
| Grant date | Mar 14, 1989 |
| Priority date | — |
| Expiry date | Sep 28, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2071
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and system is disclosed which provides precise multi-function digitally implementable modulation for a communication system. The invention provides a modulation signal for a communication system in response to an input signal from a data source. A digitized time response is generated from samples of a time domain representation of a spectrum profile of a selected modulation scheme. The invention generates and stores coefficients for each input symbol in accordance with the selected modulation scheme. The output signal is provided by a plurality of samples, each sample being generated by summing the products of a predetermined number of the coefficients and a predetermined number of the samples of the digitized time response. In a specific illustrative implementation, the samples of the output signals are converted to analog signals, filtered and used to modulate a carrier in a conventional manner. The invention is versatile in that it allows for the storage of the digitized time responses and corresponding coefficient lookup table of a number of modulation schemes, any of which may then be selected for use in accordance with the teachings of the invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.