Novel approximations to>inf/infsup/sup<|h(n)| for second order digital filters
Dong-guang He, Shu-kun Han · 2005
The expression\Sigma\min{0}\max{\infin}|h(n)|is often encountered in literature or text books where the limit-cycle bounds for digital filters or l1norm for impulse responce sequence{h(n)}is used. Several authors have tried and derived some useful upper bounds for direct form digital filters mathematically ( 1,2,3 ). In this paper, novel approximations to the sum for direct form and normal form digital filters will be given, with the only constant factor\pi/4appeared. Plots for an example are given for comparison.