User's Manual

CSM System Time/GPS and LFR/HSO Verification – continued

May 2000

3-35

SC 4812T CDMA BTS Optimization/ATP

LFR Initialization/Verification

The Low Frequency LORAN–C Receiver (LFR) is a full size card that

resides in the C–CCP Shelf. The LFR is a completely self-contained unit

that interfaces with the CSM via a serial communications link. The CSM

handles the overall configuration and status monitoring functions of the

LFR.

The LFR receives a 100 kHz, 35 kHz BW signal from up to 40 stations

(8 chains) simultaneously and provides the following major functions:

 Automatic antenna pre-amplifier calibration (using a second

differential pair between LFR and LFR antenna)

 A 1 second ±200 ηs strobe to the CSM

If the BTS is equipped with an LFR, follow the procedure in Table 3-19

to initialize the LFR and verify proper operation as a backup source for

the GPS.

If CSMRefSrc2 = 2 in the CDF file, the BTS is equipped

with an LFR. If CSMRefSrc2 = 18, the BTS is equipped

with an HSO.

NOTE

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