EE 329: Homework 8
Date Assigned: Wednesday, April 2, 1997
Date Due: Friday, April 4, 1997
Please work on the following digital filter problems.
Please begin reading Chapter 6 on FIR filters, sections 6.1-6.5.
We will design digital filters using the "window method" in
lab on Friday.
Use Matlab to design different types of IIR
low-pass filters to meet the
Sampling rate = 10,000 samples/second
A procedure that you might follow is:
Passband: 0 to 2,000 Hz
Stopband: 2,500 to 5,000 Hz
Passband ripple: less than 1 dB
Stopband attenuation: 40 dB or more
- Use filtdemo to get an idea how the four types
of IIR filters (butter, cheby1, cheby2, ellip) perform for
Note that filtdemo does not return the digital
- Design each filter in Matlab using the functions:
butter and buttord,
cheby1 and cheb1ord,
cheby2 and cheb2ord,
ellip and ellipord
- For each filter, check the frequency response with
freqz, and plot the pole and zero locations with
What to submit:
Submit a Matlab script containing the commands that you
used for the filter design.
Which type of filter achieves the specifications with the
Also, please comment on the pole and zero locations for each
filter type, and briefly explain how the pole/zero locations
correspond with the observed frequency response of
You do not have to submit the frequency response plots.
Try processing some
sound data with a digital filter.
You can load a sound file with the
f = auread('/home/pleiades/ACM/snd/spacemusic.au');
Then you can design a digital filter and process the sound with
the filter command.
The sound command can be used to play the sound.