Fundamental bridge between CT and DT
A continuous signal can be perfectly reconstructed from its discrete version using linear interpolation, if sampling occurred with frequency
가장 큰 주파수 2배 이상으로 샘플링하면 복원가능 because of Frequency-domain representation of sampling for band limited theory. Aliasing distortion을 없에기 위한 최소
Nyquist Theory Notion
Nyquist–Shannon sampling theorem
The Nyquist–Shannon sampling theorem is an essential principle for digital signal processing linking the frequency range of a signal and the sample rate required to avoid a type of distortion called aliasing. The theorem states that the sample rate must be at least twice the bandwidth of the signal to avoid aliasing distortion. In practice, it is used to select band-limiting filters to keep aliasing distortion below an acceptable amount when an analog signal is sampled or when sample rates are changed within a digital signal processing function.