Aliasing when interpolating with DFT?

1. How aliasing is avoided while taking DFT of a sequence?
2. What is aliasing in DFT?
3. What is interpolation in DFT?
4. What is aliasing in FFT?

How aliasing is avoided while taking DFT of a sequence?

Aliasing is generally avoided by applying low-pass filters or anti-aliasing filters (AAF) to the input signal before sampling and when converting a signal from a higher to a lower sampling rate.

What is aliasing in DFT?

Usually only a single period of the DTFT is plotted: In other words, when you use a sampling rate of , the frequencies 1 and are indistinguishable. This is called aliasing. In general, the continuous-time frequency is indistinguishable from any other frequency of the form , where is an integer.

What is interpolation in DFT?

Based on the achieved expressions, the interpolated DFT algorithms are generalized and a novel frequency estimator with high image component interference rejection is proposed. Simulation results show that the frequency errors returned by the new algorithm are very small even though only one or two cycles are obtained.

What is aliasing in FFT?

Recognizing Aliasing in the FFT

It is common to have acquired signals with a fundamental frequency less than half the sample rate, but the harmonics of that signal may be greater than half the sample rate and they will alias. This shows up in the FFT as frequencies that fold back into the display.