m |
|||
| Line 31: | Line 31: | ||
<span class="texhtml"> = ''X''(''z'') = (9 + 4''z''<sup> − 1</sup> + ''z''<sup> − 2</sup>) / (''z''<sup> − 3</sup>)</span>, for all z in complex plane. | <span class="texhtml"> = ''X''(''z'') = (9 + 4''z''<sup> − 1</sup> + ''z''<sup> − 2</sup>) / (''z''<sup> − 3</sup>)</span>, for all z in complex plane. | ||
| − | === Answer | + | === Answer 2 === |
Muhammad Syafeeq Safaruddin | Muhammad Syafeeq Safaruddin | ||
Revision as of 16:49, 12 September 2013
Contents
Practice Problem on Z-transform computation
Compute the compute the z-transform (including the ROC) of the following DT signal:
$ x[n]= n^2 \left( u[n+3]- u[n-1] \right) $
(Write enough intermediate steps to fully justify your answer.)
You will receive feedback from your instructor and TA directly on this page. Other students are welcome to comment/discuss/point out mistakes/ask questions too!
No need to write your name: we can find out who wrote what by checking the history of the page.
Answer 1
x[n] = n2(u[n + 2] − u[n − 1]).
$ X(z) = \sum_{n=-\infty}^{+\infty} x[n] z^{-n} $
$ = \sum_{n=-3}^{0} n^2 z^{-n} $
= 9z3 + 4z2 + z
= z3(9 + 4z − 1 + z − 2)
= X(z) = (9 + 4z − 1 + z − 2) / (z − 3), for all z in complex plane.
Answer 2
Muhammad Syafeeq Safaruddin
x[n] = n2(u[n + 3] − u[n − 1])
x[n] = n2(δ(n + 3) + δ(n + 2) + δ(n + 1) + δ(n))
$ X(z) = \sum_{n=-\infty}^{+\infty} x[n] z^{-n} $
$ X(z) = \sum_{n=-\infty}^{+\infty} n^2(\delta(n+3)+\delta(n+2)+\delta(n+1)+\delta(n)) z^{-n} $
X(z) = 9z3 + 4z2 + z + 1 for all z in complex plane
Answer 3
Write it here.
Answer 4
Write it here.
Answer 5
Tony Mlinarich
$ X(z) = \sum_{n=-\infty}^{+\infty} x[n] z^{-n} $
$ X(z) = n^2(\delta (n+3)+\delta (n+2)+\delta (n+1)+\delta (n)+\delta (n-1)) z^{-n} $
X(z) = 9z3 + 4z2 + z + 1/z<\span>
Back to ECE438 Fall 2013 Prof. Boutin
Answer 7
Yixiang Liu
$ X(z) = \sum_{n=-\infty}^{+\infty} x[n] z^{-n} $
= \sum_{n=-\infty}^{+\infty} n^2 (u[n+3] - u[n-1])z^{-n}</math>
