A method and a correspondingly operative radio receiver (10) (in either user equipment or a base transceiver station of a cellular telecommunication system) by which the radio receiver (10), in receiving signals transmitted over a radio channel, estimates the impulse response of the radio channel (so as to account for changing conditions of the radio channel) based on a received training sequence (Y) included in the received signal and corresponding to a transmitted training sequence (X), the method including a symbol averaging process (101) by which in effect, by using a calculated correlation sequence (Y.sub.c''), two sets of correlations are performed (i.e. a so-called double correlation) without actually performing two sets of correlations, and so improving the estimate of the channel impulse response to the same extent as would result from performing two sets of correlations but with fewer processor operations.