This is a very common example in most Signal Processing books I have come across.
x(n) = cos(n6) is a non-periodic discrete signal because it doesn't satisfy the periodicity condition for discrete time signals i.e, it is not of the form 2π(mN).
My question is :
the coefficient of n, i.e, Ω0=16 here can also be expressed as 16 = 16 * 2π2π = 2π112π
Now, substituting for π = 227 in above, we get 2π712∗22. So, 16 can be written as 2π(7264), which is in the form 2π(mN) with a period N=264.
I'm sure I'm missing something which may be obvious but it would be of great help if someone could point it out and explain.
Answer
The problem with your reasoning is that π≠227; π is an irrational number. There is no period N for which x[n]=x[n+N] ∀ n∈Z. Hence, the sequence is not periodic.
No comments:
Post a Comment