User's Manual Part 3

RFDS Setup and Calibration – continued

Apr 2001

3-79

SC4812ET BTS Optimization/ATP — CDMA LMF

DRAFT

RFDS Calibration

The RFDS Calibration option is used to calibrate 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

CDMA communications analyzer. The difference (offset) between the

RFDS keyed power level and 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

 BBX2s are is INS_TEST

 Cable calibration has been performed

 TX calibration has been performed and BLO has bee downloaded for

the BTS

 Test equipment has been connected correctly for a TX calibration

 Test equipment has been selected and calibrated