Aliasing

Question about aliasing

Question about aliasing
  1. What is the main condition to avoid aliasing?
  2. What causes aliasing effect?
  3. Can aliasing be removed after?
  4. Does aliasing affect amplitude?

What is the main condition to avoid aliasing?

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 causes aliasing effect?

Aliasing is Caused by Poor Sampling

A bandlimited signal is one with a highest frequency. The highest frequency is called the bandwidth ωb . If sample spacing is T, then sampling frequency is ωs =2π/T. (If samples are one pixel apart, then T=1).

Can aliasing be removed after?

Remember: after aliasing creeped into the sampled signal, it is impossible to eliminate.

Does aliasing affect amplitude?

Aliasing of Higher Harmonics

Fast-rising edges in a waveform create many high-frequency harmonics. These harmonics typically decrease in amplitude as their frequency increases. Figure 1 shows how these harmonics fold back into the display at the Nyquist point and are easily identified.

Noise Calculate noise variance from a given SNRdB
Calculate noise variance from a given SNRdB
How do you calculate noise variance?How do you calculate signal-to-noise ratio?How do you find the standard deviation of noise? How do you calculate...
Signal Reconstructing Signal with Sinus-Waves
Reconstructing Signal with Sinus-Waves
What is reconstruction in signal processing?How reconstruction is done after sampling?How can a composite signal be decomposed into its individual fr...
Filter Filtering EEG data with scipy.signal
Filtering EEG data with scipy.signal
How do you filter an EEG signal?Which filter is best for EEG signals?Which filter is used in EEG? How do you filter an EEG signal?Digital filtering ...