Agilent Technologies E8247C PSG CW - Manual (Page 176)

166 Chapter 7
Custom Real Time I/Q Baseband
Working with Differential Data Encoding
Accessing the Differential State Map Editor
• Press
Configure Differential Encoding
.
This opens the Differential State Map editor. 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.
Editing the Differential State Map
1. Press
1
>
Enter
.
This encodes the first symbol by adding a symbol table offset of 1. The symbol rotates forward through
the state map by 1 value when a data value of 0 is modulated.
2. Press
+/-
>
1
>
Enter
.
This encodes the second symbol by adding a symbol table offset of -1. The symbol rotates backward
through the state map by 1 value when a data value of 1 is modulated.
NOTE
At this point, the modulation has one bit per symbol. For the first two data values
(00000000 and 00000001) only the last bits (the 0 and the 1, respectively) are
significant.
3. Press
2
>
Enter
.
This encodes the third symbol by adding a symbol table offset of 2. The symbol rotates forward through
the state map by 2 values when a data value of 10 is modulated.
Symbol Table Offset Values Entry Area Data