Receiver troubleshooting
Introduction to Rx troubleshooting
Rx can be tested by making a phone call or in the local mode. For the local mode testing, use Phoenix service
software.
The main Rx troubleshooting measurement is RSSI measurement. This test measures the signal strength of the
received signal. I and Q branches can be measured separately. For GSM RSSI measurement, see
activation for manual measurements / GSM RSSI measurement (Page 7–10)
In GSM, the input signal can be either a real GSM signal or a CW signal that is 67.771kHz up from the carrier
frequency.
For service tool usage instructions, refer to section Service Tools and Service Concepts.
GSM Rx chain activation for manual measurements / GSM RSSI measurement
Context
RSSI signal measurement is the main Rx troubleshooting measurement. The test measures the strength of the
received signal.
I and Q branches can be measured separately. In GSM, the input signal can be either real GSM signal or CW signal
that is 67.771kHz up from the carrier frequency.
Steps
1. Start Phoenix service software.
2. From the Testing menu, choose GSM and RSSI Reading.
3. Set the RF signal generator for channel fre67.771kHz CW mode with –80dBm signal.
Alternatively set cellular tester downlink channel to the appropriate channel.
4. In the RSSI Reading window, select the appropriate band and channel.
Figure 65 RSSI Reading window
5. To start measurement/activate GSM Rx chain, click the Start button.
RM-57/58
Nokia Customer Care
RF Troubleshooting and Manual Tuning Guide
Page 7–10
Company Confidential
Issue 1
Copyright ©2005 Nokia. All Rights Reserved.
Summary of Contents for RM-57
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