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Determine and sketch the convolution of the following two signals:

x(t)= t+1,
2−t,0≤t≤110, elsewhere
h(t)=δ(t+2)+2δ(t+1).

1 Answer

1 vote

Final answer:

In this case, the convolution integral for y(t) is y(t) = (t-1) * u(t-2) + 2(t-1) * u(t-1)

Step-by-step explanation:

To determine the convolution of the given signals x(t) and h(t), we can use the convolution integral:

y(t) = ∫[x(τ) * h(t-τ)] dτ

where * denotes the convolution operation.

Let's calculate the convolution step by step:

1. Determine the limits of integration:

Since the given signals x(t) and h(t) have non-zero values only for a limited range of t, we need to determine the limits of integration accordingly. The range of t for which x(t) and h(t) are non-zero is from 0 to 10.

2. Rewrite the signals with respect to the integration variable τ:

x(τ) = τ + 1

h(t-τ) = δ((t-τ)+2) + 2δ((t-τ)+1)

3. Determine the non-zero ranges for the signals in terms of τ:

x(τ) is non-zero for 0 ≤ τ ≤ 10

h(t-τ) is non-zero for -2 ≤ t-τ ≤ -1

4. Rewrite the convolution integral based on the non-zero ranges:

y(t) = ∫[(τ+1) * [δ((t-τ)+2) + 2δ((t-τ)+1)]] dτ

= ∫[(τ+1) * δ(t-τ-2) + 2(τ+1) * δ(t-τ-1)] dτ

5. Evaluate the integral:

To evaluate the integral, we need to consider the cases when δ(t-τ-2) and δ(t-τ-1) are non-zero. These occur when the following conditions are satisfied:

-2 ≤ t-τ ≤ -1 => t-1 ≤ τ ≤ t-2

Case 1: When t-1 ≤ τ ≤ t-2

In this case, the integral becomes:

∫[(τ+1) * δ(t-τ-2)] dτ

Case 2: When 0 ≤ τ ≤ t-1

In this case, the integral becomes:

∫[(τ+1) * δ(t-τ-2) + 2(τ+1) * δ(t-τ-1)] dτ

6. Evaluate each case separately:

Case 1:

∫[(τ+1) * δ(t-τ-2)] dτ = (t-2+1) = t-1, since δ(t-τ-2) = 1 when τ = t-2.

Case 2:

∫[(τ+1) * δ(t-τ-2) + 2(τ+1) * δ(t-τ-1)] dτ

= [(t-1+1) * δ(t-t+1-2) + 2(t-1+1) * δ(t-t+1-1)]

= [(t-1+1) * δ(t-1) + 2(t-1+1) * δ(t)].

7. Combine the results from each case:

The convolution integral for y(t) becomes:

y(t) = (t-1) * u(t-2) + 2(t-1) * u(t-1)

Note: u(t) represents the unit step function.

Determine and sketch the convolution of the following two signals: x(t)= t+1, 2−t-example-1
User Lara Dougan
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