文档介绍：Practical FIR Filter Design in MATLAB
R
Revision
Ricardo A. Losada
The MathWorks, Inc.
3 Apple Hill Dr. Natick, MA 01760, USA
January 12, 2004
Abstract 4 Optimal equiripple designs with fixed transi-
tion width and peak passband/stopband ripple 7
This tutorial white-paper illustrates practical aspects of FIR Minimum-phase designs with fixed tran-
filter design and fixed-point implementation along with the sition width and peak passband/stopband
algorithms available in the Filter Design Toolbox and the ripple . . . . . . . . . . . . . . . . . . . 8
Signal Processing Toolbox for this purpose.
The emphasis is mostly on lowpass filters, but many of the 5 Optimal equiripple designs with fixed peak rip-
results apply to other filter types as well. ple and filter order 8
The tutorial focuses on practical aspects of filter design Minimum-phase designs with fixed peak
and implementation, and on the advantages and disadvan- ripple and filter order . . . . . . . . . . . 9
tages of the different design algorithms. The theory behind
the design algorithms is avoided except when needed to mo- 6 Other equiripple designs 9
tivate them.
Constrained-band equiripple designs . . . 9
Sloped equiripple filters . . . . . . . . . . 10
Contents 7 Advanced design algorithms - interpolated FIR
filters 10
1 Ideal lowpass filter 2 Further IFIR optimizations . . . . . . . . 12
Multirate implementation of IFIR design . 13
2 FIR lowpass filters 2
FIR filter design specifications . . . . . . 2 8 Interpolation filter design 13
Ideal band-limited interpolation in the
3 Optimal FIR designs with fixed transition frequency domain . . . . . . . . . . . . . 14
width and filter order 3 Ideal band-limited interpolation in the
Linear-phase designs . . . . . . . . . . . 4 time domain . . . . . . . . . . . . . . . . 15
Equiripple filters . . . . . . . . . 4 Design of FIR interpolation filters . . . . 16
Least-squares filters