Agilent Technologies E8247C PSG CW User Manual
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Chapter 7
Custom Real Time I/Q Baseband
Working with Differential Data Encoding
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 previous
illustration.
As you can see, the 1st and 4th symbols, having the same data value (00), produce the same state transition
(forward 1 state). In differential encoding, symbol values do not define location; they define the direction
and distance of a transition through the I/Q State Map.
For instructions on configuring differential encoding, see
“Understanding Differential Encoding” on
.
Data Value
Symbol Table Offset
00
01
10
11
+1
-1
+2
+0
Data = 0011100001
{
{
{
{
{
5th Symbol
1st Symbol
3rd Symbol
4th Symbol
2nd Symbol
1st
2nd
3rd
5th
4th