Keysight E8267D User Manual page 248

Custom Real Time I/Q Baseband
Working with Differential Data Encoding
2. Press +/– > 1 > Enter.
At this point, the modulation has one bit per symbol. For the first two data
NOTE
values (00000000 and 00000001) only the last bits (the 0 and the 1,
respectively) are significant.
3. Press 2 > Enter.
4. Press 0 > Enter.
At this point, the modulation has two bits per symbol. For the data values
NOTE
00000000, 00000001, 00000010, 00000011, the symbol values are 00, 01, 10,
and 11 respectively.
5. Press Return > Differential Encod ing Off On.
Notice that (UNSTORED) appears next to Differential State Map on the
NOTE
signal generator's display. Differential state maps are associated with the
user–defined modulation for which they were created.
To save a custom differential state map, you must store the user–defined
modulation for which it was designed. Otherwise the symbol table offset data
is purged when you press the Confirm Exit From Table Without Saving
softkey when exiting from the I/Q or FSK editor.
234
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.
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.
This encodes the fourth symbol by adding a symbol table offset of 0. The
symbol does not rotate through the state map when a data value of 11 is
modulated.
This applies the custom differential encoding to a user–defined
modulation.
Keysight E8357D/67D & E8663D PSG User's Guide