V120E -Agps Testing Procedure - Motorola V120e Service Manual

120e
1. Scope
This document is intended for field service center to verify whether GPS is working not
for field return units and reworked units. Since the V120E does not have a 50 ohm
direct connection for GPS test, alternative methods are proposed here to test the GPS
functionality
2.Brief description of GPS implementation on V120E
V120E- aGPS is Qualcomm MSM5100 chipset based handset with assist GPS (Global
Position System) functionality. Besides the main antenna for CDMA/AMPS modes, a
separate GPS antenna is placed on the handset. GPS antenna is located at the back
housing near the belt clip hole. Here is the block diagram of the GPS.
3. GPS functionality test methods
GPS F/E
M19
f=1575.42 MHz
Three test methods are recommended here, each test has its own requirement and
offers its advantage and disadvantage. Generally, only one test is needed for GPS
verification purpose.
3.1 GPS sensitivity test using true GPS satellites
3.1.1 Requirement
A reliable test fixture that can hold two phones side by side
A known good phone with full GPS test data
Test center is within the aGPS coverage
3.1.2 Procedure

V120E -aGPS Testing Procedure

Mode SEL1 SEL2 DIV2B
Cellular Low High Low
FM Low Low Low
PCS Hi g h High Low
GPS Hi g h Low Low
f=1391.82 MHz
RFR3300
GPS F/E
LNA
M19
Block Diagram for GPS
Motorola Confidential Proprietary
48
TCXO
19.2MHz
Main
f=367.2MHz
PLL
PLL
IFR 3300
CDMA Path
FM Path
GPS IF
(Discrete)
f=183.6 MHz
GPS/FM control
F/2
To MSM
Demodulator