Phase synchronization device integrated into the demodulator stage of a receiver of multi-phase modulator signals

Claim 1

Phase synchronization device adapted to be integrated into a demodulator stage of a receiver of digital signals phase modulated with at least two phase states, a signal being transmitted by successive packets, said device comprising: a corrector module for rotating a constellation of phase states of a received function according to information representative of an angular offset of said constellation, said angular offset corresponding to a phase shift; and two separate circuits for calculating an indication representative of the angular offset: a first calculator circuit implementing a Viterbi algorithm to produce a first angular offset indication from a sequence constituted by a predetermined number of symbols of a received signal, a second calculator circuit constituted by a phase-locked loop providing a second angular offset indication from a signal received continuously; wherein, for each packet received, said indication representative of the angular offset of the constellation of phase states is supplied to the corrector module from an output of switching means receiving on its input side: firstly, said first angular offset indication from the first calculator circuit, and secondly, said second angular offset indication from the second calculator circuit; wherein said switching means is controlled by a time-delay circuit so that said output of the switching means supplies initially, for a predetermined time, said first angular offset indication and thereafter, at a switching time corresponding to an end of said predetermined time, supplies said second angular offset indication, said second calculator circuit being initialized with said first angular offset indication at said switching time.