Digital signal processor exciter
US5418818A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 1992 |
| Grant date | May 23, 1995 |
| Priority date | — |
| Expiry date | Sep 22, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03C1/00
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digital exciter (30) for selectively modulating digital or analog input data. The digital exciter includes a digital signal modulator (32) and a digital quadrature modulator (DQM)(36) comprising two digital signal processors (DSPs). The signal modulator is controlled by a control (40). An operator can selectively determine whether the digital exciter is used for modulating either two level or four level NRZ digital data and whether the device is to provide linear modulation or frequency modulation (FM) of the input signal. An interpolator (38) interpolates a 662/3 kHz timer interrupt rate used in the signal modulator to a 400 kHz rate, thereby reducing the processing load on the DSP comprising the DQM by simplifying the sine and cosine values used in the quadrature modulation. An operator can select from among a plurality of operating parameters on a menu for controlling the signal modulator, either from a local or a remote video display terminal (VDT).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.