enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Nyquist frequency - Wikipedia

    en.wikipedia.org/wiki/Nyquist_frequency

    Early uses of the term Nyquist frequency, such as those cited above, are all consistent with the definition presented in this article.Some later publications, including some respectable textbooks, call twice the signal bandwidth the Nyquist frequency; [6] [7] this is a distinctly minority usage, and the frequency at twice the signal bandwidth is otherwise commonly referred to as the Nyquist rate.

  3. Nyquist rate - Wikipedia

    en.wikipedia.org/wiki/Nyquist_rate

    Fig 1: Typical example of Nyquist frequency and rate. They are rarely equal, because that would require over-sampling by a factor of 2 (i.e. 4 times the bandwidth). In signal processing, the Nyquist rate, named after Harry Nyquist, is a value equal to twice the highest frequency of a given function or signal

  4. Oversampling - Wikipedia

    en.wikipedia.org/wiki/Oversampling

    The Nyquist rate is defined as twice the bandwidth of the signal. Oversampling is capable of improving resolution and signal-to-noise ratio, and can be helpful in avoiding aliasing and phase distortion by relaxing anti-aliasing filter performance requirements. A signal is said to be oversampled by a factor of N if it is sampled at N times the ...

  5. Critical frequency - Wikipedia

    en.wikipedia.org/wiki/Critical_frequency

    In signal processing the critical frequency it is also another name for the Nyquist frequency. Critical frequency is the highest magnitude of frequency above which the waves penetrate the ionosphere and below which the waves are reflected back from the ionosphere. It is denoted by "f c". Its value is not fixed and it depends upon the electron ...

  6. Nyquist–Shannon sampling theorem - Wikipedia

    en.wikipedia.org/wiki/Nyquist–Shannon_sampling...

    The Nyquist–Shannon sampling theorem is a theorem in the field of signal processing which serves as a fundamental bridge between continuous-time signals and discrete-time signals. It establishes a sufficient condition for a sample rate that permits a discrete sequence of samples to capture all the information from a continuous-time signal of ...

  7. Undersampling - Wikipedia

    en.wikipedia.org/wiki/Undersampling

    Thus, the sampling frequency may be only a little bit greater than 43.2 MHz, but the input bandwidth of the system must be at least 108 MHz. Similarly, the accuracy of the sampling timing, or aperture uncertainty of the sampler, frequently the analog-to-digital converter , must be appropriate for the frequencies being sampled 108MHz, not the ...

  8. Pulse-code modulation - Wikipedia

    en.wikipedia.org/wiki/Pulse-code_modulation

    Between samples no measurement of the signal is made; the sampling theorem guarantees non-ambiguous representation and recovery of the signal only if it has no energy at frequency f s /2 or higher (one half the sampling frequency, known as the Nyquist frequency); higher frequencies will not be correctly represented or recovered and add aliasing ...

  9. Shannon–Hartley theorem - Wikipedia

    en.wikipedia.org/wiki/Shannon–Hartley_theorem

    is the bandwidth of the channel in Hz; is the signal power spectrum is the noise power spectrum; is frequency in Hz. Note: the theorem only applies to Gaussian stationary process noise. This formula's way of introducing frequency-dependent noise cannot describe all continuous-time noise processes.