Optimized windows for FIR filter design to perform maximally flat decimation stages in signal conditioning

Abstract

New cosine windows are proposed which allow maximally flat low-pass FIR filter realizations in a multistage decimation process. In digital measuring devices, this strategy is performed in order to adjust the amount of data to the storage-capabilities of the processor, in conjunction with filtering the data set available after oversampling to remove digitally the noise power produced by quantization. The consequent increase of the number of effective bits improves the dynamic performances of digital instrumentation, especially at lower frequencies.<>