Baseband signal generator for digital modulator
US5379322A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Oct 30, 1992 |
| Grant date | Jan 3, 1995 |
| Priority date | — |
| Expiry date | Oct 30, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2092
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A baseband signal generator according to the present invention performs differential encoding and mapping processings for a digital baseband signal and limits bandwidths of the obtained symbol mapping data of an I phase and a Q phase by digital filters. Each digital filter includes a circuit for accumulating symbol mapping data corresponding to a plurality of symbol sections, a plurality of ROMs provided corresponding to the plurality of symbol sections for storing symbol data corresponding to a predetermined filter waveform, and an adder for adding symbol data output from there ROMs. The adder outputs a digital baseband signal whose bandwidth is limited, which signal is converted into an analog baseband signal by a D/A converter and supplied to an analog modulation unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.