Signals and Systems - Engineering
A y[n] = x[2n]
B y[n] = x[n] x[n - 1]
C y[n] = x[n/2]
D all
ANS:B - y[n] = x[n] x[n - 1]
For time invariant system
y(n, k) = y(n - k), where y(n, k) mean shift the input by n - k, while y(n - k) mean change all the n
(a) y[n] = x[2n]
⇒ y(n, k) = x[2n - k]
y(n - k) = x[2(n - k)]
y(n, k) ≠ y(n - k) Time variant
(b) y[n] = x[n] x[n - 1]
y[n, k] = x[n - k] x[n - k - 1]
y[n - k] = x[n - k] x[n - k - 1]
y[n, k] = x[n - k] Time Invariant
(c) y[n] = x[n/2] ⇒ y[n, k] 
⇒ y[n - k] 
y[n, k] ≠ y[n - k] Time variant.
Share : |
