User`s guide

Agilent X-Series Signal Generators User’s Guide 365
Custom Digital Modulation (Option 431)
Differential Encoding
These symbol table offsets will result in one of the transitions, as shown.
When applied to the user–defined default 4QAM I/Q map, starting from the 1st symbol (data 00), the
differential encoding transitions for the data stream (in 2–bit symbols) 0011100001 appear in the
following illustration.
Data Value 00000001
transition 1 state backward
with Symbol Table Offset –1
Data Value 00000010
transition 2 states forward
with Symbol Table Offset +2
Data Value 00000011
no transition
with Symbol Table Offset 0
Data Value 00000000
transition 1 state forward
with Symbol Table Offset +1