Carrier and data recovery and demodulation system
US5001727A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 15, 1989 |
| Grant date | Mar 19, 1991 |
| Priority date | — |
| Expiry date | Feb 15, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0057
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A modulated carrier is received on a node (10) and then the I- and the Q-channels extracted with a local carrier clock (16) that is free-running relative to the modulated carrier. The I- and the Q-channels are then input to a digital signal processor (26) wherein a composite phase signal is generated representing the phase difference between the modulated carrier and the local carrier clock (16). The composite phase is output from a look-up table in an EPROM (30) and then the free-running phase the local carrier clock (16) and the modulated carrier is discriminated from the composite phase. The free-running phase is then subtracted from the composite phase to yield the phase modulation on the carrier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.