Nyquist Rate

Nyquist rate, abbreviated as \( f_n \), also called Nyquist sampling rate, is the minimum sampling rate required to accurately capture and reconstruct a continuous-time signal without introducing errors such as aliasing.  According to the Nyquist–Shannon sampling theorem, a signal must be sampled at a frequency that is at least twice the highest frequency component present in the signal in order to preserve all the information.  If the sampling rate is lower than the Nyquist rate, higher frequency components will overlap with lower ones, causing distortion and loss of original signal information. In practice, engineers often sample slightly above the Nyquist rate to provide a margin of safety and to account for imperfections in filtering and signal processing.  Thus, the Nyquist rate serves as a fundamental guideline in digital signal processing, communications, and control systems.