The present invention concerns a method for estimating the time-dispersion of a channel comprising D subchannels, wherein one computes from a received signal a set of estimated Channel Transfer Factors (CTF's) Ĥ[ν], where ν(0≦ν≦D) is the subchannel number, said method comprising a step of calculating, for a predetermined strictly positive integer d, a correlation factor Cd representing the correlations, both in amplitude and in phase, between pairs Ĥ[ν] and Ĥ[ν+d] of said computed CTF estimates. By an appropriate choice of d, the time-dispersion resolution can be adapted to most prevalent channels. The correlation is optionally corrected according to the mean channel estimation signal-to-noise ratio. This method can be used for many applications where knowing the time-dispersion characteristics of a channel is required, and is, for example, particularly suitable for designing a channel estimation filter, and for link adaptation. Application to devices and apparatus implementing these methods.