Patent ID: 8130743

Claim:
A synchronization process by a terminal of a supplementary channel associated with a symmetric two-directional principal channel, said supplementary channel and said symmetric two-directional principal channel being different in nature and being implemented by a same base station, said symmetric two-directional principal channel comprising a principal uplink channel and a principal downlink channel, particularly for low or medium speed transmission of signalling and control data and information, said supplementary channel being assigned to the downlink only, particularly for transmission of data at high speed, making use of a multicarrier technique for distribution of data in the time/frequency space, and with a sub-frame type structure, wherein the process comprises: a) synchronizing the supplementary channel at sub-frame level, wherein synchronizing is performed by the terminal and includes the following steps: 1) detecting, by the terminal, a determined time (t 0 ) on the principal downlink channel; and 2) obtaining, by the terminal, the beginning of a sub-frame of the supplementary channel, by offsetting the determined time (t 0 ) detected in 1) by a time interval with a determined duration not equal to zero (Δt), wherein the principal channel or the supplementary channel transmit(s) information about a rank within a frame of the structure of the supplementary channel, a sub-frame for which the beginning may be detected, so as to enable synchronization of the supplementary channel at the frame level by detecting the beginning of the next frame as a function of said synchronization at sub-frame level and said information about the rank of said sub-frame.