User Guide

6015/6015i/6016i/6019i (RH-55), 6012 (RM-20)
System Module Nokia Customer Care
Page 34 ©2004 Nokia Corporation Company Confidential Issue 1 - Revision 002 09/2004
VCTCXO - System Reference Oscillator
The VCTCXO provides the frequency reference for all the synthesizers. It is a voltage-
controlled, temperature-compensated, 19.2MHz crystal oscillator that can be pulled over
a small range of its output frequency.
This allows for an AFC function to be implemented for any frequency accuracy
requirements. This is done by DSP processing of received I/Q signals. Closed loop AFC
operation allows very close frequency tracking of the base station to be done in CDMA
mode. This enables the unit to track out aging effects and give the required center
frequency accuracy in Cellular and PCS bands.
Figure 14: VCTCXO clock distribution
TX Jupiter
Batman
RX VHF Synth
UHF Synthesizer
UPPUEM
VCTCXO
19.2 MHz
GPS
R