EE 329: Laboratory 8
FIR Filter Design with the Window Method
You will be given samples of an audio file that is corrupted by
Your assignment is to:
- Analyze the audio file, and specify
requirements on the frequency response of an FIR digital
filter that will remove the interference.
Your filter should remove the interference as much as possible,
but also preserve as much of the original signal as possible.
(These requirements are conflicting, so you will need to
decide on a compromise.)
- Design FIR digital filters to remove the interference.
Use two approaches to design your digital filters:
Which design achieves better results?
- By placing zeros in the z-plane, and
- Using the
described in Section 6.5 of the text.
Download the data file and load it into Matlab using
either of the following methods:
You can listen to the audio file in Matlab with the command
If you would like to here the original, uncorrupted music,
it can be loaded into Matlab with the command:
- Download the audio file
into your account, and load it into Matlab with the command:
x = auread('interfere.au');
- Downlaod the text file
and load it into Matlab with variable name x with the commands:
x = interfere;
xgood = auread('/home/pleiades/ACM/snd/spacemusic.au');
Matlab has built-in functions for generating many of the
common window functions. For a listing of the available
window commands, type
help signal and look at the "Windows" section.
Please submit a brief report describing your design procedure
and your results by Friday, April 11.
Also, I will ask each of you to demonstrate the effectiveness of
your filter to the class.
As we talk about other types of digital filters, feel free to
try them out on this particular signal processing problem.