mplexed
(in
proj_1.mat
)
signal 1
↑
8
signal 3
↑
8
signal 2
↑
8
gain
analog
anti-alias filter
digital filters
A/D converter
analog signal
Equation Chapter 1 Section 1Des
igning and Using I IR Filters
Overview
This project is intended to give you practice using M
ATLAB
to design and use IIR filters.
Particular emphasis will be given to the use of IIR filters in decimation, and to the
sensitivity of filter characteristics to quantization of the coefficients.
Notes on using M
ATLAB
For your M
ATLAB
coding, because it may take a few iterations to get each part right, and
because some filters used in one section of the project are then reused in the next section,
we strongly suggest that you write your code in
function
form and save it as
.m
files. For
help on writing functions, type
help function
, or see the Mathworks web site support
section for documentation on M
ATLAB
; similarly for all M
ATLAB
commands. To pull up the
color coded editor with a debugger, type
edit
. If you are curious to see the code for M
ATLAB
commands, type
edit command
. You can read the code for everything except the built-in
functions. The main commands used in this lab are listed in the following table.
Task(s)
M
ATLAB
statements or functions
Working with files and
variables
pwd, cd, ls, load, who
Math constants
j, pi
Making some basic signal
vectors
zeros(), ones()
Basic math and vector
operations
exp(), sum(), abs(), log10(), transpose(), length()
Polynomial operations
roots(), poly(), conv()
(see note below)
Changing the rate of a signal
decimate(), upsample(), interp()
Making IIR filters
butter(), cheby1(), cheby2(), ellip()
Ch. 7
S2004a1