Should the order of a filter be proportional to the sampling rate? I have designed a fir filter with my desired frequency response at a specific sampling rate and filter order. If I were to redesign my filter for a new higher sampling rate, should I change the filter order? I am having trouble understanding how the same filter order influences the desired frequency response at different sampling rates.
Keeping the FIR filter the same order and doubling the sample rate will effectively halve the accuracy of frequency resolution which will be noticable at low frequencies (this is based on the assumption you are using something like FFT to create your FIR, otherwise the order of the FIR and it's resolution is a bit more complicated).