Digital Signal Processing Reference
In-Depth Information
sampled representation of the signal, but if we sample too slow,
we will see a distorted version of the signal.
Below are graphs of two different sinusoidal signals being
sampled. The slower-moving signal (lower frequency) in
Figure 3.1
can be represented accurately with the indicated
sample rate, but the faster-moving signal (higher frequency) in
Figure 3.2
is not accurately represented by our sample rate. In
fact, it actually appears to be a slow-moving (low frequency)
signal, as indicated by the dashed line. This shows the importance
of sampling fast enough for a given frequency signal.
Time
Axis
Figure 3.1. Sampling a low-frequency signal
(arrows indicate sample instants).
Time
Axis
Figure 3.2. Sampling a high-
frequency signal (same sample
instants).
