R&S FSH
Digital Modulation Analyzer
Measurements on 1xEV-DO Signals
Operating Manual 1309.6275.12 - 14
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7.4.3 The Burst Power Result Display
If you equip the R&S FSH with option R&S FSH-K47E, the burst power result display
becomes available.
The Burst Power result display shows the power of the signal over a single 1xEV-DO
frame (26.66 ms). This measurement is necessary to check if the power and timing of
the bursted signals meets the requirements of the standard.
In order to capture a complete frame, you can apply a trigger from a GPS device or
another external trigger.
7.4.4 Configuring the Measurement
Some of the results depend on the measurement configuration.
7.4.4.1 Selecting the Unit of the Carrier Frequency Error
The absolute frequency error is the sum of the frequency error of the R&S FSH and
that of the device under test. If the frequency error is more than 1 kHz, the R&S FSH is
not able to synchronize with the signal. If possible, you should synchronize the receiver
and the transmitter.
The carrier frequency error can have the unit Hz or ppm.
M
Press the MEAS key.
M
Press the "Display Settings" softkey.
M
Select the "Hz" or "ppm" menu item.
The R&S FSH shows the carrier frequency error in the unit you have selected.
7.4.4.2 Changing the PN Offset
The standard uses the PN Offset to distinguish between base stations. The PN offset
determines the offset in the circulating PN sequence in multiples of 64 chips with
reference to the event second clock trigger.
Each signal is spread with a Walsh code of a length of 64 or 128 and a pseudo-random
noise code (PN code) of a length of 215. Each BTS sector in the network is assigned a
PN offset in steps of 64 chips.
If you use an external or GPS sync trigger, you have to adjust the PN Offset according
to the base station / sector you are measuring.
M
Press the MEAS key.
M
Press the "Signal Settings" softkey.
M
Select the PN OFFSET menu.
M
Enter the PN Offset you need (between 0 and 511).
