User's Manual Part 2
RFDS Setup and Calibration – continued
Mar 2001
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SCt4812T CDMA BTS Optimization/ATP
DRAFT
RFDS Calibration
The RFDS TX and RX antenna paths must be calibrated to ensure peak
performance. The RFDS calibration option calibrates the RFDS TX and
RX paths.
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.
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 XCVR. A CDMA signal at the same power level measured by the
BTS XCVR is then injected at the RX antenna directional coupler by the
RFDS keyed power level and the power level measured at the BTS
XCVR is the RFDS RX calibration offset value.
The TX and RX RFDS calibration offset values are written to the CAL
file.
Prerequisites
Ensure the following prerequisites have been met before proceeding:
BBXs are INS_TEST.
Cable calibration has been performed
TX calibration has been performed and BLO has been downloaded for
the BTS.
Test equipment has been connected correctly for a TX calibration.
Test equipment has been selected and calibrated.
Follow the procedure in Table 3-44 to calibrate the TX and RX antenna
paths.
Table 3-44: RFDS Calibration Procedure
Step Action
1 Select the RFDS tab.
2 Select the RFDS menu.
3 Select the RFDS Calibration menu item.
4 Select the appropriate direction (TX or RX) in the Direction pick list.
5 Type the appropriate channel number(s) in the Channel box.
NOTE
Separate channel numbers with a comma or dash (no spaces) if using more than one channel
number (e.g., 247,585,742 or 385–395 for numbers through and including).
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