Data acquisition and parameters (Sensor menu)
R&S NRP
1144.1400.12 4.12
E-2
Background information
Dropout tolerance
The
Dropout
parameter facilitates the clear identification of the burst end of modulated signals (e.g.
NADC). Without this parameter, the end of the burst might erroneously be detected within the burst
owing to the considerable modulation-specific power drops of such signals.
Dropout
is set at least for the
duration of modulation-dependent power drops within the burst; thus, the end of the burst cannot be
detected until the set time has elapsed after the power has dropped below the trigger threshold. If the
trigger threshold is exceeded again during the dropout time, the process restarts from the beginning.
Timing diagram
The timing diagram below shows the relation between the following parameters:
•
Trigger threshold and trigger event
•
Trigger event, exclude intervals and measurement interval
•
During the burst the signal frequently falls below the trigger threshold without the end of a burst be-
ing detected. The reason for this is that the signal then also quickly exceeds the trigger threshold,
which means that the dropout time has not yet elapsed.
•
During the dropout time indicated below, the signal no longer exceeds the trigger threshold so that
the last falling slope in the burst is detected as the end of the burst.
Power
Time
Trigger
threshold
Dropout
Exclude Start
Exclude End
Last falling slope
in the burst
Trigger event
Measurement
interval
