APPARATUS FOR GENERATING SCALED WEIGHTING COEFFICIENTS FOR SAMPLED DATA FILTERS

摘要

Method and apparatus for generating continuously variable sets of weighting coefficients for application to weighting circuits of a sampled data filter. A set standard weighting coefficients are predetermined to produce a nominal desired frequency response (Fig. 1a). The variable coefficients are generated by piecewise linear interpolation of the standard filter impulse response at points in time corresponding to the relative time position of the standard coefficients multiplied by a scale factor. Apparatus for performing the method includes a means (18) for storing the standard coefficients in an indexed manner. Means (12) are also provided for generating a sequence of numbers corresponding to the index values. The sequence of numbers are multiplied in a multiplier (15) by a scale factor supplied at a terminal (SCALE FACTOR SOURCE). The scaled coefficients are calculated according to an equation in a calculating means (22, 24, 25, 26) and means (33) are provided for storing the scaled coefficients.