1/19/2008
Copyright
2005 – Tim Hoerning
17
Nyquist Sampling Theory
•Nyquist Sampling Theory states that the sampling rate of
a system must be twice the maximum
input frequency
–fs=2*BW
•In practice, because of realistic filtering, the maximum
frequency is limited to less than1/2
•If phase detection is required, then an even higher
sampling rate should be used.
•Standard sampling frequencies
–8kHz – Telephone network – speech signals are nominally
in the 300Hz to 3.4kHz range
–44,100Hz – CD quality audio – theoretically 22kHz
signals, ~16kHz in reality
–98kHz – new emerging standard for super high fidelity
recording
