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.
Impliciations of sampling
a. at a rate below the sampling rate is aliasing which means high frequency signal content will be mapped into low frequency (or any other frequencies) regions of the sampled signal spectrum therefore will cause the wrong interpretation that there exist signal components at some frequencies which actually does not.
b. at the Nyquiest rate: Depends on the signal type. If there is no impulse at the Nyquist frequency then this will in principle satisfy Nyquist sampling rate and provide sufficient samples to recover the original signal perfectly. However for most practical cases it's avoided and a slightly higher sampling rate is preferred instead.
c. at a rate higher than Nyquist: You will have samples that satify Shannon-Nyquist sampling theorem which would allow perfect recovery of teoriginal continuous signal from its samples. However going too high unnecessarily will increase system cost. So practically (economically) it's prefererrabel to limit the highest sampling rate. On the other hand high sampling rate will permit the realization of high quality processing possible as long as you have the resources to overcome the technical and economic cost of it.
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.