User Guide

RM-17
Nokia Customer Care 3 - Service Software and Tuning Instructions
46 COMPANY CONFIDENTIAL ISSUE 1 09/2004
Copyright © 2004 Nokia. All Rights Reserved.
The results must fulfill the following limits:
Note: In later Phoenix versions the notch calibration might not be applicable anymore.
RX calibration GSM900, GSM1800 and GSM1900
The RX calibration has to be performed to determine gains at different gain settings in the RF
ASIC. The calibration must be done in all three bands:
RX calibration requires an external RF signal generator. Most of the radio communication test-
ers like CMD 55 or CMU 200 can be used also as RF signal generators, generating continuous
RF signals (CW signal) with defined levels and frequencies.
Note: Depending on Firmware version, the CMU 200 can have problems generating a non-
pulsed, non-modulated CW signal.
RX calibration in the GSM900 band combines two alignments: AFC and AGC calibrations. The
calibration of GSM 1800 and GSM 1900 bands only determines the AGC values.
The AFC calibration detects an initial AFC value and an AFC slope coefficient. The AFC cal-
ibration ensures the proper function of the initial synchronization (base station search, before
location update is done) when the phone has been set to Normal Mode. For an error free initial
synchronization, the 26 MHz frequency of the reference oscillator must be accurate enough.
Therefore, the previously calibrated AFC value is written to the DA converter and the corre-
sponding AFC voltage tunes the VCTCXO to the correct frequency.
The AGC calibration detects the gain values of the RX chain. The RF LNA can be switched
either on or off. The gain difference between on and off state is nominally 30dB and the base-
band gain which is controlled by 15 gain steps called in PHOENIX RSSI 0 to RSSI 14 each
having a graduation of 6 dB. The LNA is switched off at the steps RSSI 0 to RSSI 4.
AGC calibration detects the gain at the 3 gain steps RSSI 4, RSSI 5, and RSSI 7. All other steps
are calculated.
Calibration value / Test case Typical Low limit High limit
DTOS I Address Rc / check rx baseband
filter DTOS_I [DAC]
13 -6 +37
DTOS Q Address Rc / check rx baseband
filter DTOS_Q [DAC]
13 -6 +37
BBF I Address BIQUAD I R / check rx base-
band filter BIQUAD_IR [DAC]
13 -6 +37
BBF I Address BIQUAD I C / check rx base-
band filter BIQUAD_IC [DAC]
13 -6 +37
BBF Q Address BIQUAD Q R / check rx base-
band filter BIQUAD_QR [DAC]
21 -6 +37
BBF Q Address BIQUAD Q C / check rx base-
band filter BIQUAD_QC [DAC]
21 -6 +37
N ot c h / c h ec k r x ba se b a n d f il t er NO TC H
_ [DAC]
24 -6 +37