Keysight Technologies N5171B EXG, Руководство пользователя

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396 Keysight EXG and MXG X-Series Signal Generators User’s Guide
Custom Digital Modulation (Option 431)
Using Finite Impulse Response (FIR) Filters with Custom Modulation
Creating a User–Defined FIR Filter Using the FIR Table Editor
In this procedure, you use the
FIR Values
table editor to create and store an 8–symbol, windowed
sync function filter with an oversample ratio of 4.
Accessing the Table Editor
1. Press Preset .
2. Press Mode > ARB Custom Modulation > Single Carrier Setup > Filter > Select > Nyquist .
3. Press Filter > Define User FIR .
4. Press More 2 of 2 > Delete All Rows > Confirm Delete of All Rows .
This will initialize the table editor as shown in Figure 16-33 .
Figure 16-33 Creating a User–Defined FIR Filter Using the FIR Filter Table Editor
Entering the Coefficient Values
1. Press the Return softkey to get to the first page of the table editor.
2. Use the cursor to highlight the
Value
field for coefficient 0.
To change the filter Bbt, press Mode > Real-Time Custom Modulation >
Modulation Setup > Filter > Select Gaussian > Filter Bbt.
Enter a new value between 0.1 and 1.
Mode > ARB Custom Modulation> Single Carrier Setup > Filter >
Define User FIR > More > Delete All Rows > Confirm Delete of All
Opens a menu that
enables you to select
and load a saved file
into volatile memory.
page 255
Active only when:
FIR filter coefficient table
has minimum of two
values visible.
For details on each key, use key help as described on
page 40
.
Note:
Modulation filters are typically real and have an oversample ratio (OSR) of two or greater.
Equalization filters are typically complex and have an oversample ratio (OSR) of one (Dual ARB only).