User Manual
Bay Level Offset Calibration – continued
SC4812ET BTS Optimization/ATP — CDMA LMF
Jan 2002
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Transmit (TX) Path Calibration
The assigned channel frequency and power level (as measured at the top
of the frame) for transmit calibration is derived from the site CDF file.
For each BBX, the channel frequency is specified in the
ChannelList
CDF file parameter and the power is specified in the SIFPilotPwr
CDF file parameter for the sector associated with the BBX (located
under the
ParentSECTOR field of the ParentCARRIER CDF file
parameter).
The calibration procedure attempts to adjust the power to within +
0.5 dB
of the desired power. The calibration will pass if the error is less than
+
1.5 dB.
The TX Bay Level Offset at sites WITHOUT the directional coupler
option, is approximately 42.0 dB ±3.0 dB.
At sites WITHOUT RFDS option, BLO is approximately
42.0 dB ±4.0 dB. A typical example would be TX output power
measured at BTS (36.0 dBm) minus the BBX TX output level
(approximately –6.0 dBm) would equate to 42 dB BLO.
The TX Bay Level Offset at sites WITH the directional coupler option,
is approximately 41.4 dB ±3.0 dB. TX BLO = Frame Power Output
minus BBX output level.
Example: TX output power measured at RFDS TX coupler
(39.4 dBm) minus the BBX TX output level (approximately
–2.0 dBm) and RFDS directional coupler/cable (approximately
–0.6 dBm) would equate to 41.4 dB BLO.
The LMF Tests menu list items, TX Calibration and All Cal/Audit,
perform the TX BLO Calibration test for a XCVR(s). The All Cal/Audit
menu item performs TX calibration, downloads BLO, and performs TX
audit if the TX calibration passes. All measurements are made through
the appropriate TX output connector using the calibrated TX cable setup.
Test Pattern Drop–down Pick List
Pilot is shown as the default setting in this pick list box. The full range
of available selections and their descriptions are as follows:
Standard
– performs calibration or audit using pilot, paging, synch, and
six traffic channels with IS–97–specified gain. This pattern setting
should be used for all non–in–service calibrations and audits. Using this
pattern setting requires the selection of both a BBX and at least one
MCC.
Pilot
(default) – performs calibration using only the pilot channel. This
pattern setting should be used for in–service calibrations, and requires
selection of only a BBX.
CDFPilot
–This pattern setting is for advanced users. It performs
calibration or audit using the CDF value for pilot gain and IS–97 gain
values for all the other channels included in the Standard pattern setting
(paging, synch, and six traffic). Using this pattern setting requires the
selection of both a BBX and at least one MCC.
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