Trouble with convolution and system response to inputs

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SUMMARY

The discussion centers on solving a convolution problem involving an input signal x(t) and an impulse response h(t). The user initially approached the problem using a graphical method, reversing and shifting the input function to find overlapping intervals. After analyzing the intervals, the user concluded that for -1 < t < 0, the convolution result is represented by the equation c(t) = t + 1, indicating a rightward shift. Ultimately, the user resolved the confusion regarding the convolution output and confirmed the correct interpretation of the results.

PREREQUISITES
  • Understanding of convolution integrals in signal processing
  • Familiarity with impulse response functions
  • Graphical analysis of functions and their transformations
  • Basic knowledge of time-shifting and time-reversing signals
NEXT STEPS
  • Study the properties of convolution in linear time-invariant (LTI) systems
  • Learn about graphical methods for convolution in signal processing
  • Explore the implications of time-shifting and time-reversing on signal behavior
  • Investigate the use of MATLAB or Python for numerical convolution analysis
USEFUL FOR

Students and professionals in electrical engineering, particularly those focusing on signal processing, as well as anyone looking to deepen their understanding of convolution and system responses to inputs.

Lolsauce
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Homework Statement



x(t) is input, h(t) is the impulse response, y(t) is output

Find the system response to the input x(t)

x(t): [PLAIN]http://img10.imageshack.us/img10/5157/55570988.jpg

h(t): [PLAIN]http://img593.imageshack.us/img593/1079/52492104.jpg

Homework Equations



Now I know the convolution integral is (f*g)(t) = [URL]http://upload.wikimedia.org/math/d/1/2/d122f80c065a111d4617fb3afdae0e53.png[/URL]

But for this problem I took a more graphical approach

The Attempt at a Solution



I changed the variable to T (Tau) and chose a function to be time reversed

So I took the input and shifted then reversed the graph giving me this:
[PLAIN]http://img13.imageshack.us/img13/8581/xtshiftandreverse.jpg

Afterwards I found t in which the graphs starts overlapping and not overlapping. I found at for t < -1, convolution c(t) = 0. So for my first intervals I looked at -1 < t < 0, which overlapping begins.

[PLAIN]http://img703.imageshack.us/img703/5655/widthj.jpg

This gives me a width of (t-2) - (-3) = t + 1 which should be the equation from -1<t<0.

I repeat the same process from 0 < t < 5, and this give me an obviously overlap and convolution of c(t) = 1.

Then for the overlap starts to leave, I get and equation of:
(t-3) - 3 = t - 6, this is from the endpoint of x(t-T) leaving h(t).

So at the end I get this graph, it seems kind of whack. Especially the first interval of -1 < t < 0. Can anyone give me some tips or see a mistake I've done.

[PLAIN]http://img69.imageshack.us/img69/7213/convolution.jpg
 
Last edited by a moderator:
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Nevermind, I just solved it, lolsauce. I turns from -1 < t < 0 the equation is t + 1, means it is shift to the right by one, NOT shifted up like I had thought.
 

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