EMC PROBLEMS AS RELATED TO SIGNAL
TYPES AND MULTIPLEXING TECHNIQUES
type, generally referred to as analog, uses the actual
voice or other continuously variable waveform to
The manner in which the interference manifests itself in
modulate the transmitter directly. The other type,
the system output will vary with the multiplexing
referred to as digital, transfers an original digital data
technique and with the signal type being transferred
stream or converts the input analog waveform to a
over the system. These differences are important in the
digital bit stream of "ones" or "zeros" and uses this
isolation and identification of EMC problems.
digital bit stream to modulate the transmitter. Typical
analog and digital signals are shown in figure 3-1.
3-2. Signal Types and Multiplexing Techniques
a. General. Currently two basic types of signals
are transferred over communications systems. One
Figure 3-1. Typical analog and digital signals.