# Tag Info

### Need help with DTFT problem

Hint: it comes from the Fourier transform of $x[n]$. Once you calculate that, it will be obvious why $Y(\omega)$ only has support in those regions.
• 900
1 vote
Accepted

### Fourier transform why can I convert one of the axes into an imaginary number?

Fourier transform are able to approximate a wite range of complex function $f(t) = x(t) + j\cdot y(t)$ that satisfies the Dirichlet conditions, with negligible small mean square error. Well, in ...
• 1,586

### Periodicity of a discrete time complex exponential signal?

You have a sequence of complex numbers $$x[n]=e^{j\pi an},\quad a\in\mathbb{R},\quad n\in\mathbb{Z}\tag{1}$$ $x[n]$ is periodic with period $N$ if $x[n]=x[n+N]$ is satisfied for all $n$. For the given ...
• 80.9k
1 vote

### Periodicity of a discrete time complex exponential signal?

A signal $x[n]$ is periodic with period $P$ if $$x[n] = x[n+P]$$ for all $n$. That means that some "sinusoidal" signals which are periodic when $n$ is real-valued and continuous are not ...
• 23.1k

### How to compute convolution using the Discrete Hartley Transform

You forgot to roll the array after flipping. What you want is x0, x(n-1), x(n-1)... x2, x1 but you are using ...
• 111

### Odd artifacts after sinc interpolation

I agree that some amount of ringing is normal in sinc() interpolation. However, the function you are using does the calculation as if all samples outside the input ...
• 231
Accepted

### Odd artifacts after sinc interpolation

So, this is what I'd consider -- contrary to your title -- to be perfectly normal and expected artifacts from sinc interpolation. Keep in mind that the sinc function rings forever. This means that if ...
• 9,136