The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 03, 1993
Filed:
Jun. 06, 1991
Joel Labat, Plougastel Daoulas, FR;
Dominique Leroux, Le Trehou, FR;
Patrick Vandamme, Perros Guirec, FR;
France Telecom, Issy Les Moulineaux, FR;
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.