Summary: This module explains the MATLAB commands for FIR filter design.
fir1() designs
conventional lowpass, highpass, bandpass, and bandstop
linear-phase FIR filters based on the windowing
method. The command
b = fir1(N,Wn)
b the impulse response of a
lowpass filter of order N. The cut-off
frequency Wn must be between 0 and 1 with 1
corresponding to the half sampling rate.
b = fir1(N,Wn,'high')
N with normalized cutoff frequency
Wn.
b = fir1(N,Wn,'stop') with
Wn a two-element vector designating the
stopband designs a bandstop filter.
b = fir1(N, Wn, blackman(N)).
b = remez(N,F,A)
N+1
linear phase FIR filter of order N designed
by Parks-McClellan algorithm. F is a vector of frequency
band edges in ascending order between 0 and 1 with 1
corresponding to the half sampling rate. A is a real
vector of the same size as F which specifies the desired
amplitude of the frequency response of the points
(F(k),A(k)) and (F(k+1),A(k+1))
for odd k. For odd k, the bands
between F(k+1) and F(k+2) is
considered as transition bands.