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Chapter 6
175
Custom Arb Waveform Generator
Working with Modulation Types
Modifying a Predefined I/Q Modulation Type (I/Q Symbols) & Simulating Magnitude Errors & Phase Errors
Use the following procedure to manipulate symbol locations which simulate magnitude and phase
errors. In this example, you edit a 4QAM constellation to move one symbol closer to the origin.
1.
Press
Preset
.
2.
Press
Mode
>
Custom
>
Real Time I/Q Baseband
>
Modulation Type
>
Define User I/Q
>
More (1 of 2)
>
Load Default
I/Q Map
>
QAM
>
4QAM
.
This loads a default 4QAM I/Q modulation into the
I/Q Values
editor.
3.
Press
More (2 of 2)
.
4.
In the
I/Q Values
editor, navigate to
Data 00000000
and press
Edit Item
.
5.
Press
.235702
>
Enter
, then
.235702
>
Enter
.
When you press
Enter
the first time, the I value updates and the highlight moves to the first Q
entry. The second time, the Q value updates and the highlight moves to the following I entry.
6.
Press
Display I/Q Map
. Note that one symbol has moved, as shown.
Creating an FSK Modulation Type User File with the Frequency Values Editor
Use this procedure to set the frequency deviation for data
00
,
01
,
10
, and
11
to configure a
user–defined FSK modulation.
1.
Press
Preset
.
2.
Press
Mode
>
Custom
>
Real Time I/Q Baseband
>
Modulation Type
>
Define User FSK
>
More (1 of 2)
>
Delete All
Rows
>
Confirm Delete All Rows
.
This accesses the
Frequency Values
editor and clears the previous values.
3.
Press
600
>
Hz
.
4.
Press
1.8
>
kHz
.
5.
Press
–600
>
Hz
.
Summary of Contents for E8257D
Page 12: ...Contents xii ...
Page 50: ...36 Chapter 1 Signal Generator Overview Rear Panel ...
Page 92: ...78 Chapter 2 Basic Operation Using the Web Server ...
Page 194: ...180 Chapter 6 Custom Arb Waveform Generator Configuring Hardware ...
Page 234: ...220 Chapter 8 GPS Modulation Option 409 Real Time GPS ...