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Now I am working on making pages of solutions. Thus, some of the solutions are not available right now. Those will be completed tonight! -Jaemin

Quiz Questions Pool for Week 5


$ \text{1. Find inverse Z-transform of } \frac{1}{1-az^{-1}} \text{ where } |z|<|a|. \,\! $


$ \text{2. Find inverse Z-transform of } \frac{3z^{-3}}{1-az^{-1}} \text{ where } |z|<|a|. \,\! $

  • If you use the time-shifting property of z-transform, it can be easily solved. See the details here.

$ \text{3. Compute the Fourier series coefficients of the following signal:} \,\! $

   $ x(t)=\left\{\begin{array}{ll}1&\text{ when } 0\leq t <1 \\ 0& \text{ when } 1\leq t <2\end{array} \right. \text{ and is periodic with the period of two.} $
  • This was from one of the exercises. See the solution here.

$ \text{4. The rational Z-transform }H(z)\text{ has zero at } z_1=j\text{, and pole at }p_1=2, \,\! $

   $ \text{which is expressed as }H(z)=\frac{z-z_1}{z-p_1}\text{. Compute the magnitude of }H(e^{jw})\text{ at }w_1=\frac{\pi}{2}, w_2=-\frac{\pi}{2} \,\! $
  • See the solution here.

$ \text{Let } x(t)= \text{cos} 1000 \pi t + \text{sin} 1500 \pi t. \,\! $

$ \text{5. What is the Nyquist frequency of the signal } x(t)? \,\! $

$ \text{6. Suppose the sampling rate is }2000\text{Hz. Upsample the signal by a factor of }2\text{.} \,\! $

   $ \text{In order to get rid of aliases, what is the cutoff frequency in hertz of LPF(Low-Pass Filter)?}\,\! $
  • See the solution here.


Back to ECE 438 Fall 2010

Alumni Liaison

Ph.D. 2007, working on developing cool imaging technologies for digital cameras, camera phones, and video surveillance cameras.

Buyue Zhang