Please i need help in understanding Nyquist sampling rate. What is the implication of sampling at a lower rate than the Nyquist rate, at exactly the Nyquist rate and at a rate higher than the Nyquist rate.
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$\begingroup$ dupliucate question. the fastest sine wave needs at least two dots ,',',',', $\endgroup$– bandybabboonOct 6, 2017 at 8:05
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2 Answers
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Implications of the Shannon-Nyquist sampling :
a. Sampling rate below Nyquist rate: Aliasing happens: shifted spectra of the sampled signal will overlap; i.e., high frequency signal content will be aliased into lower frequency regions of the spectrum and low frequencies into higher, therefore, irrecoverable misinterpretations happen about the authentic (true) content of the sampled signal spectrum;
b. Sampling rate equals Nyquist rate : Depends on the signal type. If there is no impulse at the Nyquist frequency, or the spectrum is zero at the Nyquist frequency, then this will in principle satisfy Nyquist sampling rate, but requires an ideal anti-aliasing filter to be practically implemented and thus usually avoided and a slightly higher sampling rate is preferred instead.
c. Sampling rate larger than Nyquist rate : Satifies Shannon-Nyquist sampling theorem, allowing perfect and unique recovery of the original continuous-time signal from its samples. However, going too high, unless necessary will increase system cost. So practically it's best to limit the sampling rate to a satisfactory minimum or an achievable maximum.
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$\begingroup$ @lilfancy I'm glad I could help..! If you think that it's a satisfactory one then you can select it so that the question will not float indefinetely ;-) $\endgroup$– Fat32Oct 7, 2017 at 19:40
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dupliucate question. the fastest sine wave needs at least two dots ,',',',', so you need ,' to give amplitudes of the fastest possible sound's peak and trough, as each sound is a vibration around zero. so you need twice as many dots as your frequency. so a 44k cd can replay 22k sine wave which consist of 2 dots, and 11k that consist of 4 digital dots. the dots can be 16bit, 8 bit, any precision level at that sampling rate.
