The invention relates to a channel estimating method for an FBMC telecommunication system. The disclosed estimating method uses the signal before it is filtered by the analysis filter bank.According to a first embodiment, the preamble is composed of a repetition in time of an elementary pattern of pilot symbols and the channel estimate is made in the stationary part of the preamble.According to a second embodiment, the preamble is composed of a predetermined pattern of pilot symbols distributed in time and in frequency, and the channel estimate may be made on a typical part of the preamble.The channel thus estimated is used to make an equalisation before the analysis filter bank.