What is the bandwidth of a signal?
The term bandwidth is a general one that is used to describe the width or extent a
spectrum
(
29
f
X
occupies in the frequency domain.
Since a real signal has a magnitude spectrum that is symmetric with respect to
0
=
f
, and
has a phase spectrum that is antisymmetric with respect to
0
=
f
, the positive spectrum
for
0
≥
f
(or sometimes called the onesided spectrum) is sufficient in the evaluation of
the bandwidth for a signal that is real.
For convenience, this is often done, resulting in a
“onesided” bandwidth or simply bandwidth that is based on the onesided spectrum.
Of course, if the signal is complex or when there is a need to consider the spectrum over
both positive and negative frequencies (that is, a twosided spectrum), we will end up
with a “twosided” bandwidth.
In general, there is no universal usage, and one just has to be consistent when comparing
bandwidths of different signals.
As an example, consider the spectrum
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
 Fall '07
 Prof.C.C.Ko
 Frequency, Bandwidth, FM radio, spectrum, 95

Click to edit the document details