Digital filtering method for use in frequency range by e.g. digital finite impulse response filter, involves multiplying signals with coefficients, and summing products when number of non null-coefficients are very small and very large

摘要

The method involves dividing an input signal into multiple signals, and transforming the input signals from a finite impulse response (FIR) filter with transfer functions. The signals are multiplied with coefficients i.e. sample values of a desired frequency response. A pair of products is summed when the number of non null-coefficients is very small and very large, where the digital filtering in a frequency range is realized in a parallel form or in a cascade form.