Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

What does delaying a signal mean? Graphically? Mathematically? Is it, advancing to the next numbers, or using the previous numbers? Suppose i have $x[n] = \{0,1,2,3,4,5\}$ and i use $x[n-m]$ (example $x[n-3]$, what actually happens behind the scenes)? I can't get the gist and main concept behind.. thanks . Lesson: z transforms, laplace, transforms.

Our topic deals with z transforms and an introductory to dsp.

share|cite|improve this question
Delay means previous samples, samples, samples. Think echo, echo, echo. – dls Feb 3 '12 at 5:43
lets say x[n] = [1,2,3,4,5,6,7] then what whould x[n-3] look like? – WantIt Feb 3 '12 at 6:21

It's confusing if you write $x[n] = [0,1,2,\ldots]$, so don't do that.

What you really mean is that $$\begin{align} x(0) &= 0, \\ x(1) &= 1, \\ x(2) &= 2, \\ \end{align}$$ and so on. Then it is easy to see that if you have a signal $y$ such that $y(n) = x(n-3)$, then $$\begin{align} y(3) &= x(3-3) = x(0) = 0, \\ y(4) &= 1, \\ y(5) &= 2, \\ \end{align}$$ and so on.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.