Difference between Periodogram and DTFT

Why do we use the periodogram (and not just the DTFT, for example) for the estimation of a spectrum of a random signal?

Answer 1

[Christian David]

Hi,

The result of the DTFT is a continuous function, so it not can be determined in a computer. The alternative is DTF, which can be calculated using FFT algorithm.

Periodogram is a Power Spectral Density Estimate, so it is the square of absolute value of the DTF function.