A general characterization of lowpass FIR frequency response in the transition band

A general model is derived for the frequency response of lowpass FIR filters in the transition band which has applications to filter bank aliasing calculations and convergence of the LMS algorithm. It is shown that as a class, these filters exhibit a frequency response whose squared magnitude rolls off approximately as (/spl omega//sub 0/-/spl omega/)/sup q/, where q is a positive exponent that is expressed generically in terms of the filter order and the angular stopband edge frequency /spl omega//sub 0/.<
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