A METHOD AND A DEVICE FOR CONSTRUCTING NEW SAMPLE VALUES USED IN A FIR ALGORITHM

摘要

The present invention relates to the method and a device for constructing new sample values to be used in a Finite Impulse Response, denoted FIR, algorithm, wherein a sampled analog signal contains at least a periodic fundamental component that has an actual period length that may deviate from a nominal period length, the device (3) comprises: a measuring unit (7) configured to continuously measure an actual fundamental frequency of the analog signal, a sampling unit (1 ) for sampling the analog signal at controlled time steps, a first storage (2) for storing the sample values as original sampling values, a system period length determination module (8) configured to continuously determine the actual fundamental period length based on the measured the actual fundamental frequency, a calculating unit (6) configured, to determine a new sampling time step based on the actual fundamental period length such that the number of new sampling time steps in the actual fundamental period is the same as the number of original sampling time steps in the nominal fundamental period, to calculate, for a finite number of stored original sample values, a finite number of new sample values, using said new sampling time step, wherein each of new sample values is calculated based on at least two original sample values, and a second storage unit (4) for storing the new calculated sample values.