Chapter 13 373
Custom Digital Modulation
Using the Arbitrary Waveform Generator
Creating a Custom TDMA Digital Modulation State
In this procedure, you learn how to set up a single-carrier NADC digital modulation with customized
modulation type, symbol rate, and filtering.
This section teaches you how to perform the following tasks:
• “Selecting a Digital Modulation Setup” on page 373
• “Modifying the Modulation Type and Symbol Rate” on page 373
• “Modifying the Filter” on page 373
• “Configuring the RF Output” on page 374
Selecting a Digital Modulation Setup
1. Press
Preset.
2. Press
Mode > Custom > ARB Waveform Generator.
3. Press
Setup Select > NADC.
Modifying the Modulation Type and Symbol Rate
1. Press
Digital Mod Define > Modulation Type > PSK > QPSK and OQPSK > QPSK.
2. Press
Symbol Rate > 56 > ksps.
Modifying the Filter
1. Press
Filter > Select > Nyquist.
2. Press
Return > Return.
Generating the Waveform
Press
Digital Modulation Off On.
This generates a waveform with the custom single-carrier NADC digital modulation state created in the
previous sections. The display changes to Dig Mod Setup: NADC (Modified). During waveform
generation, the DIGMOD and I/Q annunciators appear and the custom single-carrier digital modulation state
is stored in volatile memory. The waveform is now modulating the RF carrier.
For instructions on storing this custom single-carrier NADC digital modulation state to non-volatile memory
catalog, see “Storing a Custom TDMA Digital Modulation State” on page 374.