ELEC 320, Fall 1997

**Revision in class on September 22:**
Items 4 and 5 below will be due on Friday, September 26.

- Please continue reading Chapter 3, Sections 3.3 and 3.4. Also review Section 1.2 on signals, with particular attention to the impulse function delta(t), step function u(t), and time-shifted signals.
- Please show me a draft you your lab report this week. The final report will be due on Monday, September 29.
- Problem 3.1 in the text. Note that the term "unit-pulse
response" in the text means the same thing as "impulse response",
which I have used in class. Also, the impulse response h[n] is
computed
**with all initial conditions equal to zero**. This is because h[n] is used via convolution to compute the zero-state response (ZSR) of a system, and the ZSR has all initial condtions equal to zero. -
Consider a linear, time-invariant, discrete-time
system with impulse response h[n] plotted below.
Plot the system output y[n] when the input is the sequence
x[n] shown below.

*Hint:*y[n] = x[n] * h[n] where * denotes convolution!*[GRAPHIC NOT AVAILABLE IN HTML FILE -- SEE PAPER VERSION]*

Check your result using MATLAB and the

`conv`command as follows:>> h = [1, 1, 1]; >> x = [1, 1, 1, 1, 1]; >> y = conv(x, h); >> n = 0:length(y)-1; >> stem(n, y)

*A note about MATLAB help:*Remember that MATLAB has on-line help available. For example, typing

`help conv`will describe the convolution command and how to use it. Also, if you type`hthelp`on the Suns, then a hypertext version of help will be opened in a new window. This might be useful to view the available commands and follow links to related commands. - Problem 3.4 in the text, for the signals
x[n] and v[n] in Figure P3.4(b)
*only*. Show all of the steps when you compute your answer on paper, and use the MATLAB`conv`command to check your results.

Thank you.