ELEC 320, Fall 2006
Prof. Rich Kozick

## Homework 10

Date Assigned: Friday, October 27, 2006
Date Due: Wednesday, November 1 (items 3 and 4) and Friday, November 3, 2006 (item 5)

1. Please continue to study Chapter 3 in the Lathi text on Fourier series.

2. Please remember that for Lab 7 on November 1 and 6, submit an abstract that describes your lab design project. Include the title, the names of the participants, and a brief description of what you plan to do.

3. Please experiment with the Fourier series demonstrations at
http://www.jhu.edu/~signals/ with the title "Fourier Series Approximation".

Under Fourier Series Approximation:
(a) Which signal is easier to approximate, the "Rectangular Pulse" or "Triangle"? That is, if 10 coefficients are used, which signal is better approximated? Please explain why this is the case by observing the shape of the magnitude spectrum at the higher frequencies.
(b) How is the magnitude spectrum of "Noise" different from the other signals? Specifically, what do you notice about the "strength" of the higher frequencies in the magnitude spectrum?

Try the demo that is titled "Listen to Fourier Series". Did you learn anything interesting from this demo?

4. Please solve the following problems in Chapter 3 of the Lathi text, and submit your solutions on November 1. Show all of your work. If you obtain a result with your calculator, write down exactly what you input to your calculator, and identify the result from your calculator.
Problems 3.1-2 and 3.4-3 (parts b and c only).

5. Develop a Matlab program to plot the truncated Fourier series using your results from problems 3.4-3 (parts b and c).

The program fstrun.m that we used in class may be a useful template for your program. Please try to do this for Wednesday, but you may submit your results on Friday, November 3.

Thank you.