Method and circuit arrangement for producing a QPSK signal on which a carrier signal is superposed
US5289503A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1991 |
| Grant date | Feb 22, 1994 |
| Priority date | — |
| Expiry date | Sep 10, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2046
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method of generating a composite signal in the form of a QPSK signal on which an additional carrier signal is superposed, wherein a carrier signal is conducted through two series connected, switchable phase shifters. One of the phase shifters is controlled by one of two data signals. Both data signals are logically linked with one another by a logic circuit, and the resulting linkage signal used to control the other phase shifter. The phase states into which each phase shifter can be switched are selected and the linkage signal formed from the data signals such that, with the available values of the data signals, the carrier signal passing through the phase shifters is brought into the phase positions that should exist with the additional carrier signal superposed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.