User's Manual

Bay Level Offset Calibration68P09255A69-3

Aug 2002

1X SC4812ET Lite BTS Optimization/ATP Software Release 2.16.1.x

PRELIMINARY

3-81

Table 3-38: Set Up Test Equipment for RF Path Calibration

Step Action

! CAUTION

To prevent damage to the test equipment, all transmit (TX) test connections must be via the 30 dB

directional coupler for 800 MHz or via a 30 dB coupler with a 20 dB in-line attenuator for 1900

MHz.

For TX path calibration, connect the test equipment as shown in Figure 3-13, Figure 3-14, or

Figure 3-15, depending on the communications analyzer being used.

Transmit (TX) Path Calibration Description

The assigned channel frequency and desired power level at the frame TX

ports for transmit calibration are derived from the BTS CDF file. Each

BBX at the site is assigned to a sector and carrier. These are specified

respectively in the sector and carrier fields of the

ParentCARRIER

parameter in each BBXs CDF file block. The channel frequency and

desired power for the assigned sector are specified respectively in the

ChannelList and SIFPilotPwr parameters of the CDF block for the

CARRIER to which the BBX is assigned.

NOTE

Be sure the bts-#.cdf and cbsc-#.cdf files loaded on the LMF

computer are current. The LMF will obtain carrier and channel

information from these files and insert it into the appropriate

CDMA Test Parameter screen. Failure to have the most current

files from the CBSC can result in incorrect channel information

being used to calibrate the BTS and unfavorable affects on BTS

performance. Carrier and channel numbers should only be

entered manually for special test cases or as a last resort.

The calibration process attempts to adjust the measured 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 BLO for the SC4812ET Lite is approximately 42.0 dB ±5.0 dB.

BLO is the gain in dB between the known power output of the BBX and

the measured power at the TX port. BLO is derived by deducting the

known BBX power output from the power measured at the TX port or

(Measured Power) - (BBX TX Power Output).

Example:

Measured Power (at TX port) = 36.0 dBm

Known BBX TX Power Output = -6.0 dBm

BLO = (36.0) - (-6.0) = 42.0 dB gain