1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Using an impulse response and an output to find an input using Z-transform

  1. May 1, 2012 #1
    1. The problem statement, all variables and given/known data
    An LTI digital system with impulse response h[n] = 2(1/4)^n u[n-1] produces an output y[n] = (-3)^n u[n-1]. Determine the corresponding input x[n].

    2. Relevant equations

    I believe that Y[z] = X[z]H[z]

    3. The attempt at a solution

    So I started by finding the z-transform of h[n]. Which I think is (0.25z)/(z-0.25)^2.

    I then went on the find to the z-transform of y[n]. Which I think is z/(z+3).

    So then I divided them and got 4((z-0.25)^2) / (z+3)..

    I can't figure out how to take the inverse z-transform to get x[n]. I think my z-transforms might be wrong, or I'm just dividing incorrectly.
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted