Method of synchronization of the uplink channel of a simulcast network

Method of synchronization on the uplink channel of a Simulcast network which comprises a plurality of fixed receivers and a selection unit, the method comprising the steps according to which:

• a) all the receivers are placed in a synchronization search mode, in which they search fox a synchronization pattern in a radio signal sent by a mobile terminal on the uplink channel, by scanning a radio channel associated with the uplink channel;
• b) when one or more receivers receive the radio signal and detect said synchronization pattern, they produce a respective initial synchronization context value, which indicates the delay between a time reference of the received radio signal and a time reference of the network, and transmit to the selection unit said initial synchronization context value;
• c) the selection unit transmits to all the receivers respectively the or a predefined one of the initial synchronization context values received in step b);
• d) each receiver having detected the synchronization pattern in step b) starts processing the radio signal on the basis of the initial synchronization context value that it has produced and/or on the basis of the initial synchronization context value that it has received from the selection unit, while the other receivers start processing the radio signal on the basis of the initial synchronization context value that they have received born the selection unit;
• e) each receiver, after step d),
• transmits to the selection unit useful information frames obtained by processing the radio signal, as well as quality information or similarity information associated with each item of useful information in said frames;
• maintains it synchronization context using a synchronization tracking algorithm based on the useful information contained in the radio signal, and processes the radio signal on the basis of its maintained synchronization context;
• transmits the current value of its duly maintained synchronization context to the selection unit, with at least some of the useful information frames;
• f) at regular intervals, the selection unit chooses a defined current synchronization context value horn a current synchronization context values respectively transmitted by the receivers, according to a criterion based on the quality information or the similarities respectively associated with the useful information of the corresponding frame, and transmits the duly selected current synchronization context value to all the receivers.