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Keysight EXG and MXG X-Series Signal Generators User’s Guide
Custom Digital Modulation (Option 431)
Using Customized Burst Shape Curves
— the modulation type
When the rise and fall delays equal 0, the burst shape is attempting to synchronize the maximum
burst shape power to the beginning of the first valid symbol and the ending of the last valid symbol
of the timeslot. The following figure illustrates a bursted signal in an EDGE frame with a rise delay of
0 and a fall delay of +1 bit.
The signal generator firmware computes optimum burst shape based on the settings you’ve chosen
for modulation. You can further optimize burst shape by lining up the data portion with the
modulation. For example, if you’re designing a new modulation scheme, do the following:
— Adjust the modulation and filtering to set the spectrum you want.
— Adjust the burst rise and fall delay and rise and fall time for the timeslots.
If you find that the error vector magnitude (EVM) or adjacent channel power (ACP) increases when
you turn bursting on, you can adjust the burst shape to assist with troubleshooting.
