The sequences x[n] = {−1, 3, 1} and h[n] = {−2, −2, −3} are convolved. Find the sum Σy[n] of all samples of y[n] = x[n] ∗ h[n].
Convolution & LTI systems worksheet with answers
1.Easy
x[n] = {−1, 3, 1}, n = 0…2h[n] = {−2, −2, −3}
Σy[n] =
2.Easy
A system with the impulse response h[n] = {3, 2, −2, −1} (n = 0…3) receives the step input x[n] = 3·u[n]. Find the output y[5].
h[n] = {3, 2, −2, −1}x[n] = 3·u[n]
y[5] =
3.Medium
The pulse x(t) = 2 for 0 ≤ t < 0.5 s (zero elsewhere) is applied to a system with h(t) = e−2tu(t). Find the output y(1.5) at t = 1.5 s, after the pulse has ended.
x(t) = 2, 0 ≤ t < 0.5 sh(t) = e−2tu(t)t = 1.5 s
y(1.5) =
4.Medium
The input x(t) = 10·e−3tu(t) is applied to a system with h(t) = e−0.5tu(t). Find the output y(0.25) at t = 0.25 s.
x(t) = 10·e−3tu(t)h(t) = e−0.5tu(t)t = 0.25 s
y(0.25) =
5.Hard
A system obeys y′(t) + 1·y(t) = 2·x(t). Find its impulse response at t = 0.2 s, h(0.2).
y′ + 1y = 2xt = 0.2 s
h(0.2) =
6.Hard
A system obeys y′(t) + 1·y(t) = 2·x(t). Find its impulse response at t = 0.1 s, h(0.1).
y′ + 1y = 2xt = 0.1 s
h(0.1) =
Answer key
- 1. Σy[n] = −21
- 2. y[5] = 6
- 3. y(1.5) = 0.08555
- 4. y(0.25) = 1.641
- 5. h(0.2) = 1.637
- 6. h(0.1) = 1.81
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