The sequences x[n] = {4, 4, 2} and h[n] = {4, 3, −2} both start at n = 0. Find the largest sample ymax of y[n] = x[n] ∗ h[n].
Convolution & LTI systems worksheet with answers
1.Easy
x[n] = {4, 4, 2}, n = 0…2h[n] = {4, 3, −2}, n = 0…2
ymax =
2.Easy
A system with the impulse response h[n] = {1, 3, 1} (n = 0…2) receives the step input x[n] = 2·u[n]. Find the output y[4].
h[n] = {1, 3, 1}x[n] = 2·u[n]
y[4] =
3.Medium
The input x(t) = 1·e−4tu(t) is applied to a system with h(t) = e−5tu(t). Find the output y(0.5) at t = 0.5 s.
x(t) = 1·e−4tu(t)h(t) = e−5tu(t)t = 0.5 s
y(0.5) =
4.Medium
A system has the impulse response h(t) = e−0.5tu(t). The input is a step x(t) = 4·u(t). Find the output y(2) at t = 2 s.
h(t) = e−0.5tu(t)x(t) = 4·u(t)t = 2 s
y(2) =
5.Hard
The input x(t) = 10·cos(30t) is applied to a system with h(t) = 5·e−10tu(t). Find the amplitude Ym of the steady-state output.
h(t) = 5e−10tu(t)x(t) = 10cos(30t)
Ym =
6.Hard
A system obeys y[n] = 0.8·y[n − 1] + 2·x[n] and starts at rest. The input is the unit step x[n] = u[n]. Find y[2].
y[n] = 0.8y[n − 1] + 2x[n]x[n] = u[n]
y[2] =
Answer key
- 1. ymax = 28
- 2. y[4] = 10
- 3. y(0.5) = 0.05325
- 4. y(2) = 5.057
- 5. Ym = 1.581
- 6. y[2] = 4.88
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