User Manual

TX Pilot Time Offset Acceptance Test
PRELIMINARY 2
SC 4812ET BTS Optimization/ATP – CDMA LMF
July 1999
4-16
Background: Pilot Offset
Acceptance Test
This test verifies the transmitted Pilot channel element Pilot Time Offset
of each BBX2 carrier keyed up at a specific frequency per the current
CDF file assignment. All tests are performed using the external
calibrated test set controlled by the same command. All measurements
will be via the appropriate TX OUT (BTS/RFDS) connector.
The Pilot Gain is set to 262 for each antenna and all TCH elements from
the MCCs are forward link disabled. The BBX is keyed up using both
bbxlvl and bay level offsets to generate a CDMA carrier (with pilot
channel element only, Walsh code 0). BBX power output is set to
40 dBm as measured at the TX OUT connector (on either the BTS or
RFDS directional coupler).
The calibrated communications test set measures and returns the Pilot
Time Offset in uS, verifying results meet system tolerances: Pilot Time
Offset should be within <
3 µs of the target PT Offset (0 S).
The BBX2 then de-keys, and the applicable redundant BBX2 is assigned
to the current TX antenna path under test. The test is then repeated.
Pilot Time Offset Test
The LMF Tests menu list item, Pilot Time Offset, performs the Pilot
Time Offset test for a XCVR(s). All measurements are made through the
appropriate TX output connector using the calibrated TX cable setup.
This test is included in the All TX, All TX/RX and Full Optimization
tests.
Prerequisites
Before attempting to run any ATP tests, ensure the following have been
completed:
 CSMs, GLI2s, BBX2s, and MCCs have correct code load and data
load
 Primary CSM, GLI, and MCCs are INS
 BTS has been Optimized/Calibrated
 BBX2s are OOS–RAM
 Test equipment is connected for ATP tests (see Figure 3-16 through
Figure 3-19).
 Test equipment is warmed up 60 minutes and calibrated
 Test cables are calibrated
 GPIB is on
 LMF is logged into the BTS