Spring computer lab assignment ece introduction discrete-time signalsprof

Spring/Summer 2018

Computer Lab Assignment 1

(a) What is the range of the variable x, which makes y real?

3. Consider the continuous-time signal given by x(t) = 128t2e−0.3466tcos(0.6πt +π 3)ua(t). (a) Plot x(t). Hence, find the its max. value and the time where the max. occurs.

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(b) Determine the integral A = x(t)dt.

5. Generate and plot the following discrete-time signals (sequences):

(a) x1(n) = δ(n − 3) ∗ δ(n + 2),
(b) x2(n) = 2δ(n − 320),
(c) x3(n) = 3.6δ(n + 6) + 2.4δ(n − 5), (d) x4(n) = u(−n + 2)u(2n + 9),
(e) x5(n) = p4(n) ∗ p2(n),

average power and plot 5 periods. For part (c), show that it is possible to express the

sequence using a simple formula. As for the aperiodic signals, just plot 40 samples.

Make two plots of the resulting signal: one as a function of time (in msec.), and the other

as a function of the sample index n used in tn = nt. Calculate the digital frequency of the

(a) Sketch x(n). Hint: Choose the range |n| ≤ 40.

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9. Consider the following discrete-time exponential signal x(n) = 75(−0.95)nu(n − 3). (a) Plot x(n) over the range n = 0, 1, 2, . . . , 20.