Configuring the Internal Baseband Source
R&S
®
SMW200A
252User Manual 1175.6632.02 ─ 16
– Scalar | I | + | q |
The clipping limit is related to the absolute maximum of all the I and Q values | I
| + | q | . The I and Q components are mapped separately, the angle changes.
However, signal clipping not only changes the peak value but also the average
value and the effect on the crest factor is unpredictable.
Example:
The following figures demonstrate the effect of the clipping on the crest factor for typi-
cal scenarios.
Enabled is clipping with vector mode (|I+q|), using a signal configuration with 2 active
channels.
Constellation diagram of the signal without clipping,
shows the level mapping
Constellation diagram with clipping level 80%, vector
mode (|I+q|) The circle emphasizes the changed
constellation points
●
Filtering is applied subsequently. The used filters are specially designed so that
they filter out the distortion.
4.5.2 Common Settings
The start dialog of each digital standard follows a repeating dialog structure that com-
prises the tabs "General", "Trigger In", "Marker" and "Clock".
The "General" tab comprises the primary settings of the standard, the functions for
storing and recalling settings. It also provides access to further functions and dialogs,
like the "Filter" settings.
The "Trigger In", "Marker" and "Clock" tabs comprise the settings related to the corre-
sponding function.
In the following, we use the "Custom Digital Modulation" dialog to explain the provided
common settings. The related remote-control commands are listed in the order "Cus-
tom Digital Modulation", "ARB", "Multi Carrier CW".
Common Functions and Settings in the Baseband Domain
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