Agilent Technologies ESG series, User And Programming Manual, Page: 429 / 446

Real-Time I/Q Baseband Generator User’s and Programming Guide 6-13
ESG Family Signal Generators Theory of Operation
Options UN8 and 202 Understanding Differential Encoding
Entering a value of +1 will cause a 1-state forward transition through the I/Q State Map,
as shown in the following illustration.
NOTE The following I/Q State Map illustrations show all of the possible state
transitions using a particular symbol table offset value. The actual
state-to-state transition would depend upon which state the modulation had
started in.
Entering the following values in the Differential State
Map, and pressing
Return
>
Differential Encoding Off On
until
On
is highlighted, differentially encodes the
user-defined I/Q or FSK modulation that is present in
the I/Q State Map.
• For data 00000001, enter -1.
• For data 00000010, enter 2.
• For data 00000011, enter 0.
These symbol table offsets will result in one of the
transitions shown in the following illustrations.
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)
Data Value 00000000
transition 1 state forward
with Symbol Table 1
Data Value 00000001
transition 1 state backward
with Symbol Table Offset -1
Data Value 00000010
transition 2 states forward
with Symbol Table 2
Data Value 00000011
no transition
with Symbol Table 0