Synchronization at multiframe level of a mobile terminal of a radiocommunications system

Method of synchronization at multiframe level of a mobile terminal of a radiocommunications system on a traffic down path which exhibits a multiframe structure with a determined number L of useful data frames, of the type comprising the use by the mobile terminal, in order to recover the synchronization at the multiframe level, of signalling codes respectively contained in signalling frames which are sent by a base station of the system while being respectively associated with each useful data frame of the traffic down path, wherein:

• the number N of distinct values of the signalling codes which are usable by the mobile terminal to recover the synchronization at multiframe level, hereinafter called synchronization values, is less than L;
• said N synchronization values are apportioned to the associated signalling frames in such a way that there exist integers P and Q, not both equal to unity, such that the P×Q synchronization values respectively contained in P sequences of associated signalling frames each comprising Q signalling frames respectively associated with any Q consecutive useful data frames of a multiframe, form a unique word;
• a) the mobile terminal performs monitorings inside at least P determined monitoring windows, so as to detect signalling frames respectively associated with useful data frames of the traffic down path;
• b) the size of the monitoring windows is adapted so that, in each of them, the mobile terminal receives at least Q signalling frames respectively associated with any Q consecutive useful data frames of the traffic down path;
• c) the mobile terminal recovers the synchronization at multiframe level on the basis of a word formed of the P×Q synchronization values respectively contained in the P×Q associated signalling frame thus received.

Signal intended to be sent by a base station of a radiocommunications system, on a determined carrier frequency on which is set up a traffic down path which exhibits a multiframe structure with a determined number L of useful data frames,

• comprising signalling frames respectively associated with each useful data frame and each containing a signalling code, and wherein:
• the number N of distinct values of the signalling codes which are usable by the mobile terminal to recover the synchronization at multiframe level, hereinafter called synchronization values, is less than L;
• and
• said N synchronization values are apportioned to the associated signalling frames in such a way that there exist integers P and Q, not both equal to unity, such that the P×Q synchronization values respectively contained in P sequences of associated signalling frames each comprising Q signalling frames respectively associated with any Q consecutive useful data frames of a multiframe, form a unique word.