User Manual
RFDS Setup and Calibration – continued
Jan 2002
3-105
SC4812ET BTS Optimization/ATP — CDMA LMF
RFDS Calibration
The RFDS Calibration option is used to calibrate the RFDS TX and RX
paths.
TX Path Calibration – For a TX antenna path calibration the BTS
XCVR is keyed at a pre–determined power level and the BTS power
output level is measured by the RFDS. The power level is then measured
at the TX antenna directional coupler by the power measuring test
equipment item being used (power meter or analyzer). The difference
(offset) between the power level at the RFDS and the power level at the
TX antenna directional coupler is used as the TX RFDS calibration
offset value.
RX Path Calibration – For an RX antenna path calibration the RFDS is
keyed at a pre–determined power level and the power input level is
measured by the BTS BBX. A CDMA signal at the same power level
measured by the BTS BBX is then injected at the RX antenna directional
coupler by the communications system analyzer. The difference (offset)
between the RFDS–keyed power level and power level measured at the
BTS BBX is the RFDS RX calibration offset value.
RFDS calibration and the CAL file – The TX and RX RFDS
calibration offset values are written to the CAL file in the slot[385]
Block.
TSIC channel frequency – For each RFDS TSIC, the channel
frequency is determined at the lower third and upper third of the
appropriate band using the frequencies listed in Table 3-51.
Table 3-51: RFDS TSIC Calibration Channel Frequencies
System Channel Calibration Points
800 MHz (A and B) 341 and 682
1.9 GHz 408 and 791
Before installing any test equipment directly to any TX
OUT connector, verify that there are no CDMA channels
keyed. Failure to do so can result in serious personal injury
and/or equipment damage.
WARNING
RFDS Calibration Procedure
Prerequisites
Test equipment has been selected.
Test equipment and test cables have been calibrated.
TX calibration has been performed and BLO data has been
downloaded to the BBXs.
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