What is the effect of sampling on the original frequency spectrum?

What is the effect of sampling on the original frequency spectrum?

Sampling produces a larger number of frequency components not in the original spectrum, even components having negative frequency. The sampled signal has a spectrum that is periodic at the sampling frequency (20 Hz) and has an even symmetry about 0.0 Hz, as well as symmetry about the sampling frequency, fs.

What is sampling and aliasing effect?

As you already know, sampling of a continuous-time signal results in repeating its spectrum in the frequency domain. When the sampling rate is not large enough (not larger than 2B Hz), then interference among adjacent bands will occur, and this results in the phenomenon of aliasing.

Why does the frequency spectra change when the sampling?

At a higher sampling rate, these copies are farther apart. Additionally, your sampling points will be in different places at different sampling rates, so you may get different lobing behavior.

When does a digital signal match the sampling rate?

The key point to remember is that a digital signal cannot contain frequencies above one-half the sampling rate (i.e., the Nyquist frequency/rate). When the frequency of the continuous wave is below the Nyquist rate, the frequency of the sampled data is a match.

What is the difference between sampling and downsampling?

Terminology: sampling – creating a discrete signal from a continuous process. downsampling (decimation) – subsampling a discrete signal upsampling – introducing zeros between samples to create a longer signal aliasing – when sampling or downsampling, two signals have same sampled representation but differ between sample locations.

What happens to a sine wave during sampling?

In particular, the original sine wave of 0.95 frequency misrepresents itself as a sine wave of 0.05 frequency in the digital signal. This phenomenon of sinusoids changing frequency during sampling is called aliasing. Just as a criminal might take on an assumed name or identity (an alias ), the sinusoid assumes another frequency that is not its own.