Agilent Technologies E4428C, User Manual, Page: 642 / 700

618 Chapter 17
W-CDMA Downlink Digital Modulation for Receiver Test
Setting Up for a Compressed Mode Signal
Setting the Frame Power Offset and Triggering the Compressed Frame Function
NOTE
If you are using the spectrum analyzer setup shown in the section “Connection Diagram for
Measuring the DPCH Symbol Power” on page 611 , it is best to perform Step 3 once you
have completed the spectrum analyzer setup in the section, “Measuring the DPCH Symbol
Power” on page 619 . Because this is a demodulation measurement, the spectrum analyzer
needs to capture the DPCH before DTX periods are incorporated. If the spectrum analyzer
encounters a DTX period while making a demodulation measurement, it will not recognize
the DPCH transmission.
1. Set the compressed frame power relative to the non-compressed (normal) frames.
a. Move the cursor to highlight the
PwrOffs
field.
b. Press
6
>
dB
.
This enables you to compensate for reduced spreading gain. The higher power level makes the
compressed frames easier to view.
2. Press the
Apply Channel Setup
softkey.
3. Press the
Compressed Mode Start Trigger
softkey.
The compressed mode function terminates when the
Compressed Mode Stop Trigger
softkey is pressed, an
external stop trigger signal is received, or when the
Apply Channel Setup
softkey is pressed. You can also stop
the transmitted compressed mode signal after a set number of transmissions by changing the
TGPRC
field
from
Infinity
to the desired number of repetitions. To restart the compressed mode function, just press
the
Compressed Mode Start Trigger
softkey or send an external start trigger signal.