Agilent Technologies E4428C, Руководство пользователя

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Chapter 11 363
GPS Modulation
Real Time GPS
Selecting the Data Format
1. Press
Mode
>
More (1 or 2)
>
GPS
>
Real Time GPS.
2. Ensure that Raw is the selected data mode.
If Raw is not the current data mode, press
Data Mode Raw Enc TLM
to Raw.
3. Ensure that PN9 is the selected data sequence.
If PN9 is not the current data sequence, press
Data
>
PN Sequence
>
PN9
.
4. Press
Real-time GPS Off On
to On.
5. Press
RF On/Off
to toggle the RF output on.
The modulated signal is now available at the RF OUTPUT connector. Notice that the display annunciators
for
GPS
and
I/Q
are on and the display annunciator
RF OFF
has changed to
RF ON
.
Setting Up the GPS Receiver
Setup the GPS receiver to accept the carrier frequency and output the data and clock signal used for the bit
error rate measurements.
Selecting the BERT Data Pattern and Total Bits
1. Access the BERT function.
For an ESG with Option UN7 Installed
Press
Aux Fctn
>
BERT
>
Configure BERT
.
For an ESG with Options UN7 and 300 Installed
Press
Aux Fctn
>
BERT
>
Baseband BERT
>
Configure BERT
.
If the
Data
softkey does not show that PN9 is the selected data pattern, press
Data
>
PN9.
The selected PN sequence must match the data PN sequence used on the channel being measured. For
example if the DCH (DTCH) is using PN9 data, then the data selection in the BERT function must also
be PN9.
2. Press
Total Bits
>
1000
>
Bits
.
1000 bits at 50 bps takes 20 seconds to test
.