I just dabble in digital signal processing, to some thought still not familiar with, hope to get guidance,
Filtering is an important digital signal processing technology, I understand, about the filter, with Fourier transform this tool, in theory, through Fourier transform, multiplied by a filter function in frequency domain, such as low-pass, the specific frequency with filtering function to filter out, and then through the inverse discrete Fourier transform, you can achieve filtering? So why the introduction of IIR and FIR digital filter? With several chapters section design method of this type of filter,