Technical Brief; General Description - LG L704I Service Manual

3. TECHNICAL BRIEF

3.1 General Description

The L704i supports UMTS-800, UMTS-2100, GSM-900, DCS-1800, and PCS-1900 based
GSM/GPRS/UMTS. All receivers and the UMTS transmitter use the radioOne
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 L704i is shown in Figure 1-1. One antenna collects
base station forward link signals and radiates handset reverse link signals. The antenna connects with
receive and transmit paths through a FEM(Front End Module) (plus two duplexers for UMTS high-band
and low-band operations).
QUALCOMM's branded chipset that implements a Zero-IF radio architecture.
1
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Fig 1.1 Block diagram of RF part
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3. TECHNICAL BRIEF
1 Zero-IF architecture to
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