B. Sampling Theorem

Question 1

• simply stated, criteria require that the sampling frequency be at least twice the highest frequency (Nyquist frequency) contained in the signal can be reconstructed exactly without any error or loss of information.

Answer 1

Sampling theorem (also called Nyquist sampling theorem or Nyquist criterion)

Question 2

Nyquist

Answer 2

fs >= 2*f-max

Question 3

• is an undesirable effect that is seen in sampled systems.

Answer 3

Aliasing

Question 4

When the input frequency is greater than half the sampling frequency fs (i.e., Nyquist frequency, fn), the sampled points do not adequately represent the input signal. Inputs at these higher frequencies are observed at a lower frequency called, _______________________.

Answer 4

aliased frequency fa

Question 5

Aliasing can be avoided by means of applying ________________ or ________________ before sampling.

Answer 5

low-pass filters or anti-aliasing filters

Question 6

These filters restrict the signal bandwidth to satisfy the sampling theorem.

Answer 6

low-pass filters or anti-aliasing filters

Question 7

If a low-pass filter is not used and the sample rate is below the Nyquist rate, the digital recording system can actually reconstruct an ________________.

Answer 7

incorrect frequency