Abstract: A method processes a signal by storing a template sequence composed of a number N of consecutive digital samples of the signal; calculating a sequence of extended sums that includes, for each digital sample, an extended sum of absolute values of differences between N most recent digital samples and the samples of the template sequence; detecting minima of the sequence of extended sums; and estimating a period of the signal as a time interval between two consecutive minima of the sequence of extended sums. The method also estimates the noise level of the signal as a ratio between most recently-detected minimum and maximum of said sequence of extended sums. The method also generates a reduced-noise replica of the signal as a weighted average of the template sequence and of the current samples of the signal processed between two consecutive minima of said extended sum, the weighted average being calculated using weights based on the estimated noise level.