| 摘要 |
A decimation filter arrangement for reducing the sampling frequency of a time-discrete input signal from fi to fu, fu not being a rational portion of fi. For the generation of the required filter coefficients this arrangement comprises clock pulse generators producing first clock pulses ki(.) at a rate fi and second clock pulses au(.) at a rate fu. The arrangement also comprises a coefficients generator in which a deviation component dn is calculated which indicates the ratio between the time interval located between a clock pulse au(.) and the immediately preceding clock pulse ki(.), and the time interval 1/fi between two consecutive clock pulses ki(.). In response to this deviation component this coefficients generator produces N vilter coefficients, the mth filter coefficient, m=0, 1, 2, . . . N-1, being equal to an(m)=h[(dn+m)Vo]. Herein the function h(v) represents the impulse response of an FIR-filter, v a continuous variable in the interval - INFINITY <v< INFINITY and Vo a predetermined constant.
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