Title :
Least squared error FIR filters with flat amplitude or group delay constraints
Author :
Gopinath, Ramesh A.
Author_Institution :
IBM T. J. Watson Res., Yorktown, NY, USA
Abstract :
Finite impulse response lowpass filters with prescribed number of zeros at /spl omega/=/spl pi/ and either prescribed group delay flatness or prescribed amplitude flatness and linear phase are designed by minimizing a squared error. A simple orthogonal projection of least squared error filters (that are often available in closed form) onto a linear subspace determined via Thiran filters (for group delay flatness) and via Herrmann filters (for amplitude flatness) gives the desired filters.
Keywords :
FIR filters; delays; filtering theory; least squares approximations; linear phase filters; low-pass filters; poles and zeros; FIR filters; Herrmann filters; Thiran filters; finite impulse response lowpass filters; flat amplitude constraint; flat group delay constraint; least squared error filters; linear phase; linear subspace; orthogonal projection; zeros; Band pass filters; Delay; Digital filters; Finite impulse response filter; Frequency domain analysis; Nonlinear distortion; Nonlinear filters; Polynomials; Spline; Subspace constraints;
Journal_Title :
Signal Processing Letters, IEEE
DOI :
10.1109/LSP.2003.815611
