Device for recovering a carrier wave provided with a circuit for inhibiting dummy frequency acquisitions
US5233631A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1991 |
| Grant date | Aug 3, 1993 |
| Priority date | — |
| Expiry date | Jun 6, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0069
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The invention concerns a device for recovering a carrier wave provided with a circuit for inhibiting dummy frequency hookings or acquisitions for phase-modulated digital signals in N states with a phase N=2P, device including a phase locking loop provided with demodulation, a voltage-controllable oscillator, a 90.degree. phase shifter, for the low-pass filtering of basic band signals X1(t) and Y1(t), a loop filter, for sampling the signals X1(t) and Y1(t) and having a sampling frequency Fe so that Fe>(2p+1.vertline.n.vertline.)/T where T is the reciprocal value of the modulation speed and, associated with this loop, a circuit for drawing up the filtered signals Sign Sin (2P .PHI.k) and Sign Cos (2P .PHI.k) required for detection of the direction of variation of the phase error, a phase/frequency comparator, loss of synchronization and hooking detection and an adaptive filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.