408
Keysight EXG and MXG X-Series Signal Generators User’s Guide
Custom Digital Modulation (Option 431)
Differential Encoding
Press
Mode
>
ARB Custom Modulation
>
Single Carrier Setup
>
Quick Setup
(desired format)
>
Modulation Type
>
Select > More > Define User I/Q
>
More 1 of 2
>
Load Default I/Q Map
>
QAM
>
4QAM
.
This loads a default 4QAM I/Q modulation and displays it in the I/Q table editor.
The default 4QAM I/Q modulation contains data that represent 4 symbols (00, 01, 10, and 11)
mapped into the I/Q plane using 2 distinct values (1.000000 and
−
1.000000). These 4 symbols will
be traversed during the modulation process by the symbol table offset values associated with each
Figure 16-41
Accessing the Differential State Map Table Editor
Press
Configure Differential Encoding
.
This opens the
Differential State Map
table editor, as shown. At this point, you see the data
for the 1st symbol (00000000) and the cursor prepared to accept an offset value.You are now
prepared to create a custom differential encoding for the user–defined default 4QAM I/Q
modulation. Refer to
Figure 16-42
Editing the Differential State Map
1.
Press
1
>
Enter
.
Data
Symbol Table Offset Values Entry Area
