User's Manual

TX Spectral Purity Transmit Mask Acceptance Test

SC 4812T CDMA BTS Optimization/ATP

May 2000

4-6

Tx Mask Test

This test verifies the spectral purity of each BBX carrier keyed up at a

specific frequency, per the current CDF file assignment. All tests are

performed using the external calibrated test set, controlled by the same

command. All measurements are via the appropriate TX OUT

(BTS/RFDS) connector.

The Pilot Gain is set to 541 for each antenna and all channel elements

from the MCCs are forward-link disabled. The BBX is keyed up, using

both bbxlvl and bay level offsets, to generate a CDMA carrier (with pilot

channel element only). BBX power output is set to obtain +40 dBm as

measured at the TX OUT connector (on either the BTS or RFDS

directional coupler).

TX output power is set to +40 dBm by setting BTS power

level to +33.5 dBm to compensate for 6.5 dB increase from

pilot gain set to 541.

NOTE

The calibrated communications test set measures and returns the

attenuation level of all spurious and IM products in a 30 kHz resolution

bandwidth. With respect to the mean power of the CDMA channel

measured in a 1.23 MHz bandwidth in dB, verify that results meet

system tolerances at the following test points:

 1.7/1.9 GHz:

– at least –45 dB @ + 900 kHz from center frequency

– at least –45 dB @ – 900 kHz from center frequency

 800 MHz:

– at least –45 dB @ + 750 kHz from center frequencY

– at least –45 dB @ – 750 kHz from center frequency

– at least –60 dB @ – 1980 kHz from center frequency

The BBX2 then de-keys, and, if selected, the MCC is re-configured to

assign the applicable redundant BBX2 to the current TX antenna path

under test. The test is then repeated.