Keysight EXG and MXG X-Series Signal Generators User’s Guide 229
Basic Digital Operation for N5172B/82B with Options 653/655/656/657
Using the Custom Real-Time I/Q Baseband Generator
Using the Custom Real-Time I/Q Baseband Generator
The custom real-time format enables you to create unframed digital modulation with user-defined
data, filtering, symbol rate, modulation type, burst shape, differential data encoding, and other
format parameters.
You can choose a predefined mode where filtering, symbol rate and modulation type are defined by
the digital modulation standard, or a user-defined custom modulation.
Selecting Predefined Custom Modulation Modes
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Base Band.
3. Press More (1 of 3) > More (2 of 3) > Predefined Mode > APCO 25 w/C4FM.
4. Press More (3 of 3).
This selects a predefined mode where filtering, symbol rate and modulation type are defined by the
APCO 25 w/C4FM digital modulation standard and returns you to the top-level custom modulation
menu. To configure data, burst shape, and differential data encoding parameters, see the next
section, “Creating User-Defined Custom Modulation.”
To output this predefined custom modulation, complete the steps in “Generating the Waveform”
on page 231 and “Configuring the RF Output” on page 231.
To deselect a predefined mode, press the following keys:
Mode > Custom > Real Time I/Q Base Band > More (1 of 3) > More (2 of 3) > Predefined Mode >
None