LG KT610, Service Manual

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3. TECHNICAL BRIEF
3. TECHNICAL BRIEF
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3.1 GENERAL DESCRIPTION
The KT610 supports UMTS-2100, GSM-900, GSM-1800, and GSM-1900 based
GSM/GPRS/EDGE/UMTS. All receivers and the UMTS transmitter use the radioOne 1 Zero-IF
architecture to eliminate intermediate frequencies, directly converting signals between RF and
baseband. The quad-band GSM transmitters use a baseband-to-IF upconversion followed by an offset
phase-locked loop that translates the GMSK-modulated or 8-PSK-modulated signal to RF.
A generic, high-level functional block diagram of KT610 is shown in Figure 3-1. One antenna collects
base station forward link signals and radiates handset reverse link signals. The antenna connects with
receive and transmit paths through a SKY77519(EDGE PAM+ASM). The UMTS receive paths each
include an LNA, an RF band-pass filter, and a downconverter that translate the signal directly from RF-
to-baseband using radioOne ZIF techniques.
The RFIC’s Rx analog baseband outputs, for the receive chains, connect to the MSM IC. The UMTS
and GSM Rx baseband outputs share the same inputs to the MSM IC.
[Fig. 3.1] Block diagram of RF part
1 QUALCOMM’s branded chipset that implements a Zero-IF radio architecture.