Patent ID: 8417749

Claim:
A processor-implemented method for specifying a digital multirate filter, comprising: inputting an objective function for determining an effectiveness of a plurality of digital multirate filters; inputting an input and output characteristic of the digital multirate filters; wherein the characteristic includes an overall rate change value that specifies a ratio of integers equaling an input sample rate divided by an output sample rate, each of the digital multirate filters having the input sample rate and the output sample rate; factoring the overall rate change value into a plurality of ordered sets of at least one factor, with each factor in each of the ordered sets being an integer or a reciprocal of an integer, and the overall rate change value being a product of the at least one factor in the ordered set; wherein each of the digital multirate filters corresponds to one of the ordered sets and includes a respective stage for each factor in the ordered set, with the factor specifying a local rate change value of the respective stage; evaluating a plurality of respective values of the objective function for the digital multirate filters, the respective value for each of the digital multirate filters indicating the effectiveness of the digital multirate filter; selecting a one of the digital multirate filters in response to the respective values of the objective function; and storing the at least one factor in the ordered set that corresponds to the selected one of the digital multirate filters.