LG CX830 Service Manual

Features of CX830

1. Wave Type

CELLULAR : G7W

●

PCS: G7W

●

2. Frequency Scope
Receive Frequency (MHz)Transmit Frequency (MHz)

3. Rated Output Power : CELLULAR = 0.25W

PCS = 0.25W

4. Output Conversion Method : This is possible by correcting the key board channel.

5. Voltage and Current Value of Termination Part Amplifier (Catalogue included)

PowerCurrentVoltagePart NameMODE

0.25W400mA4.2VAWT6307RCELLULAR

GPSPCSCELLULARPCSCELLULAR

1575.421930~1990869.82~893.191850~1910824.82 ~ 848.19

6. Functions of Major Semi-Conductors

Terminal operation control and digital signal processing MSM6500

Memory MCP

(TY9000A000BMGF)

7. Frequency Stability

CELLULAR : ±0.5PPM

●

● PCS : ±0.1PPM

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Flash Memory (1024Mbit) + SDRAM (512Mbit)

Storing of terminal operation program

Converts Rx RF signal to baseband signalRFR6500
Converts baseband signal to Tx RF signalRFT6150

0.25W400mA4.2VAWT6308RPCS

FunctionClassification

CDMA Mobile Subscriber Unit
CX830

SERVICE MANUAL

SERVICE MANUAL

DUAL BAND CDMA

[PCS/Cellular/w/GPS]

CDMA MOBILE PHONE

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Table of Contents

General Introduction……………………………………………………………………………...3

CHAPTER 1. System Introduction

1. CDMA Abstract…….………………………………………………………………….…….…..4

2. Features and Advantages of CDMA Mobile Phone…………....................................... . 5

3. Structure and Functions of Dual-band CDMA Mobile Phone……………………….…..8

4. Specification……………………………………………………………………………………..9

5. Installation………………………………………………………………………………………14

CHPATER 2. NAM Input Method

1. NAM Program Method and Telephone Number Inputting Method……………………16

CHAPTER 3. Circuit Description

1. RF Transmit/Receive Part……………………………………………………………….……26

2. Digital/Voice Processing Part……………………………………………………………….32

CHAPTER 4. Trouble Shooting………………………………………………………………...37

CHAPTER 5. Safety……………………………………………………………………..………133

CHAPTER 6. Glossary……………………………………………………………………….…136

APPENDIX…………………………………………………………………………………...……148

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General Introduction

General Introduction

The CX830 phone has been designed to operate on the latest digital mobile communication technology, Code
Division Multiple Access (CDMA). This CDMA digital technology has greatly enhanced voice clarity and can
provide a variety of advanced features. Currently, CDMA mobile communication technology has been
commercially used in Cellular and Personal Communication Service (PCS). The difference between them is the
operating frequency spectrum. Cellular uses 800MHz and PCS uses 1.9GHz. The CX830 support GPS Mode, we
usually call it tri-band phone. Also, CX830 works on Advanced Mobile Phone Service (S-GPS). We call it dual­mode phone. If one of the Cellular, PCS base stations is located nearby, Call fail rate of triple-mode phone is less
than dual-mode phone or single-mode phone.

The CDMA technology adopts DSSS (Direct Sequence Spread Spectrum). This feature of DSSS enables the phone
to keep communication from being crossed and to use one frequency channel by multiple users in the same specific
area, resulting that it increases the capacity 1 0 times more compared with that in the analog mode currently used.
Soft/Softer Handoff, Hard Handoff, and Dynamic RF power Control technologies are combined into this phone to
reduce the call being interrupted in a middle of talking over the phone.
Cellular and PCS CDMA network consists of MSO (Mobile Switching Office), BSC (Base Station Controller), BTS
(Base station Transmission System), and MS (Mobile Station). The following table lists some major CDMA
Standards.

Basic air interface

Network

Service

Performance

* TSB –74: Protocol between an IS-95A system and ANSI J-STD-008

TIA/EIA/IS-95-A/B/C

ANSI J-STD-008

TIA/EIA/IS-634
TIA/EIA/IS/651

TIA/EIA/IS-41-C

TIA/EIA/IS-124

TIA/EIA/IS-96-B

TIA/EIA/IS-99
TIA/EIA/IS-637
TIA/EIA/IS-657

TIA/EIA/IS-97

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TIA/EIA/IS-98

ANSI J-STD-018
ANSI J-STD-019

TIA/EIA/IS-125

Protocol between MS and BTS for Cellular & AMPS

Protocol between MS and BTS for PCS

DescriptionDesignatorCDMA Standard

MAS-BS

PCSC-RS

Intersystem operations

Nom-signaling data comm.

Speech CODEC

Assign data and fax

Short message service

Packet data

Cellular base station

Cellular mobile station

PCS personal station

PCS base station

Speech CODEC

Chapter1. System Introduction

Chapter1. System Introduction

1. CDMA Abstract

The CDMA mobile communication system has a channel hand-off function that is used for collecting the information
on the locations and movements of mobile telephones from the cell site by automatically controlling several cell site
through the setup of data transmission routes, and then enabling one switching system to carry out the automatic
remote adjustment. This is to maintain continuously the call state through the automatic location confirmation and
automatic radio channel conversion when the busy subscriber moves from the service area of one cell site to that of
another by using automatic location confirmation and automatic radio channel conversion functions. The call state
can be maintained continuously by the information exchange between switching systems when the busy subscriber
moves from one Cellular system area to the other Cellular system area.

In the Cellular system, the cell site is a small-sized low output type and utilizes a frequency allocation system that
considers mutual interference, in an effort to enable the re-use of corresponding frequency from a cell site separated
more than a certain distance.

Unlike the time division multiple access (TDMA) or frequency division multiple access (FDMA) used in the band
limited environment, the Code Division Multiple Access (CDMA) system which is one of digital Cellular systems is
a multi-access technology under the interference limited environment. It can process more number of subscribers
compared to other systems (TDMA system has the processing capacity three times greater than the existing FDMA
system whereas CDMA system, about 12~15 times of that of the existing system).

CDMA system can be explained as follows; TDMA or CDMA can be used to enable each person to talk alternately
or provide a separate room for each person when two persons desire to talk with each other at the same time, whereas
FDMA can be used to enable one person to talk in soprano, whereas the other in bass (one of the two talkers can
carry out synchronization for hearing in case there is a bandpass filter function in the area of the hearer). Another
available method is to make two persons to sing in different languages at the same time, space, and frequency when
wishing to let the audience hear the singing without being confused. This is the characteristic of CDMA.

On the other hand, when employing the CDMA technology, each signal has a different pseudo-random binary
sequence used to spread the spectrum of carrier. A great number of CDMA signals share the same frequency
spectrum. In the perspective of frequency area or time area, several CDMA signals are overlapped. Among these
types of signals, only desired signal energy is selected and received through the use of pre-determined binary
sequence; desired signals can be separated, and then received with the correlators used for recovering the spectrum
into its original state. At this time, the spectrums of other signals that have different codes are not recovered into its
original state, and appears as the self-interference of the system.

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2. Features and Advantages of CDMA Mobile Phone

2.1 Various Types of Diversities

When employing the narrow band modulation (30kHz band) that is the same as the analog FM modulation system
used in the existing Cellular system, the multi-paths of radio waves create a serious fading. However, in the CDMA
broadband modulation (1.25MHz band), three types of diversities (time, frequency, and space) are used to reduce
serious fading problems generated from radio channels in order to obtain high-quality calls.
Time diversity can be obtained through the use of code interleaving and error correction code whereas frequency
diversity can be obtained by spreading signal energy to wider frequency band. The fading related to normal
frequency can affect the normal 200~300KHz among signal bands and accordingly, serious effect can be avoided.
Moreover, space diversity (also called path diversity) can be realized with the following three types of methods.
First, it can be obtained by the duplication of cell site receive antenna. Second, it can be obtained through the use of
multi-signal processing device that receives a transmit signal having each different transmission delay time and then,
combines them. Third, it can be obtained through the multiple cell site connection (Soft Handoff) that connects the
mobile station with more than two cell sites at the same time.

2.2 Power Control

The CDMA system utilizes the forward (from a base station to mobile stations) and backward (from the mobile
station to the base station) power control in order to increase the call processing capacity and obtain high-quality calls.
In case the originating signals of mobile stations are received by the cell site in the minimum call quality level (signal
to interference) through the use of transmit power co ntrol on all the mobile stations, the system capacity can be
maximized. If the signal power of mobile station is received too strong, the performance of that mobile station is
improved. However, because of this, the interference on other mobile stations using the same channel is increased
and accordingly, the call quality of other subscribers is reduced unless the maximum accommodation capacity is
reduced.
In the CDMA system, forward power control, backward open loop power control, and closed loop power control
methods are used. The forward power control is carried out in the cell site to reduce the transmit power on mobile
stations less affected by the multi-path fading and shadow phenomenon and the interference of other cell sites when
the mobile station is not engaged in the call or is relatively nearer to the corresponding cell site. This is also used to
provide additional power to mobile stations having high call error rates, located in bad receptio n areas or far away
from the cell site.
The backward open loop power control is carried out in a corresponding mobile station; the mobile station measures
power received from the cell site and then, reversely increases/decreases transmit power in order to compensate
channel changes caused by the forward link path loss and terrain characteristics in relation to the mobile station in the
cell site. By doing so, all the mobile transmit signals received by the base station have same strength.

Moreover, the backward closed loop power control used by the mobile station is performed to control power using
the commands issued out by the cell site. The cell site receives the signal of each corr esponding mobile station and
compares this with the pre-set threshold value and then, issues ou t power in crease/decrease commands to the
corresponding mobile station every 1.25msec (800 times per second). By doing so, the gain tolerance and the
different radio propagation loss on the forward/backward link are complemented.

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2.3 Voice Encoder and Variable Data Speed

The bi-directional voice service having variable data speed provides voice communication which employs voice
encoder algorithm having power variable data rate between the base station and the mobile station. On the other hand,
the transmit voice encoder performs voice sampling and then, creates encoded voice packets to be sent out to the
receive voice encoder, whereas the receive voice encoder demodulates the received voice packets into voice samples.

One of the two voice encoders described in the above is selected for use depending on inputted automatic conditions
and message/data; both of them utilize four-stage frames of 9600, 4800, 2400, and 1200 bits per second for Cellular
and 14400,7200,3600,1800 bits per second for PCS, so PCS provide relatively better voice quality (almost twice
better than the existing cellular system). In addition, this type of variable voice encoder utilizes adaptive threshold
values on selecting required data rate. It is adjusted in accordance with the size of background noise and the data rate
is increased to high rate only when the voice of caller is inputted.

Therefore, background noise is suppressed and high-quality voice transmission is possible under the environment
experiencing serious noise. In addition, in case the caller does not talk, data transmission rate is reduced so that the
transmission is carried out in low energy. This will reduce the interference on other CDMA signals and as a result,
improve system performance (capacity increased by about two times).

2.4 Protecting Call Confidentiality

Voice privacy is provided in the CDMA system by means of the private long code mask used for PN spreading.
Voice privacy can be applied on the traffic channels only. All calls are initiated using the public long code mask for
PN spreading. The mobile station user may request voice privacy during call setup using the origination message or
page response message, and during traffic channel operation using the long code transition request order.
The Transition to private long code mask will not be performed if authentication is not performed. To initiate a
transition to the private or public long code mask, either the base station or the mobile station send s a long code
transition request order on the traffic channel.

2.5 Soft Handoff

A handoff in which the mobile station commences communications with a new base station without interrupting
communications with the old base station. Soft handoff can only be used between CDMA channels having identical
frequency assignments.

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2.6 Frequency Re-Use and Sector Segmentation

Unlike the existing analog Cellular system, the CDMA system can reuse the same frequency at the adjacent cell.
there is no need to prepare a separate frequency plan. Total interference generated on mobile station signals received
from the cell site is the sum of interference generated from other mobile stations in the same cell site and interference
generated from the mobile station of adjacent cell site. That is, each mobile station signal generates interference in
relation to the signals of all the other mobile stations.

Total interference from all the adjacent cell sites is the ratio of interference from all the cell sites versus total
interference from other mobile stations in the same cell site (about 65%). In the case of directional cell site, one cell
normally uses a 120°sector antenna in order to divide the sector into three. In this case, each antenna is used only for
1/3 of mobile stations in the cell site and accordingly, interference is reduced by 1/3 on the average and the capacity
that can be supported by the entire system is increased by three times.

2.7 Soft Capacity

The subscriber capacity of the CDMA system is flexible depending on the relation between the number of users and

service classes. For example, the system operator can increase the number of channels available for use during the
busy hour despite the drop in call quality. This type of function requires 40% of normal call channels in the standby
mode during the handoff, in an effort to avoid call disconnection resulting from the lack of channels.
In addition, in the CDMA system, services and service charges are classified further into different classes so that
more transmit power can be allocated to high class service users for easier call set-up; they can also be given higher
priority of using hand-off function than the general users.

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3. Structure and Functions of tri-band CDMA Mobile Phone

The hardware structure of CDMA mobile phone is made up of radio frequency (RF) part and logic part. The RF part

is composed of Receiver part (Rx), Transmitter part (Tx) and Local part (LO). For the purp ose of operating on tri­band, It is necessary dual Tx path, tri Rx path, dual PLL and switching system for band selection. The mobile phone
antenna is connected with the frequency separator which divide antenna input/output signals between Cellular
frequency band (824~894 MHz) and PCS frequency band (1850~1990MHz). Each separated path is linked with the
Cellular duplexer and PCS duplexer. Duplexer carries out separating Rx band and Tx band. The Rx signals from the
antenna are converted into intermediate frequency(IF) band by the frequency synthesizer and frequency down
converter. And then, pass SAW filter which is a band pass filter for removing out image frequency. The IF output
signals that have been filtered is converted into digital signals via Analog-to-Digital Converter (ADC). In front of the
ADC, switching system is required to choose which band path should be open. The digital signals send to 5
correlators in each CDMA de-modulator. Of these, one is called a searcher whereas the remaining 4 are called data
receivers (fingers). Digitalized IF signals include a great number of call signals that have been sent out by the
adjacent cells. These signals are detected with pseudo-noise sequence (PN Sequence). Signal to interference ratio
(C/I) on signals that match the desired PN sequence are increased through this type of correlation detection process,
but other signals obtain processing gain by not increasing the ratio. The carrier wave of pilot channel from the cell
site most adjacently located is demodulated in order to obtain the sequence of encoded data symbols. During the
operation with one cell site, the searcher searches ou t multi-paths in ac cordance with terrain and building reflections.
On three data receivers, the most powerful 3 paths are allocated for the parallel tracing and receiving. Fading
resistance can be improved a great deal by obtaining the diversity combined output for de-modulation. Moreover, the
searcher can be used to determine the most powerful path from the cell sites even during the soft handoff between the
two cell sites. Moreover, 3 data receivers are allocated in order to carry out the de-modulation of these paths. Output
data that has been demodulated changes the data string in the combined data row as in the case of original
signals(deinterleaving), and then, are demodulated by the forward error correction decoder which uses the Viterbi
algorithm.

Mobile station user information send out from the mobile station to the cell site pass through the digital voice

encoder via a mike. Then, they are encoded and forward errors are corrected through the use of convolution encoder.
Then, the order of code rows is changed in accordance with a certain regulation in order to remove any errors in the
interleaver. Symbols made through the above process are spread after being loaded onto PN carrier waves. At this
time, PN sequence is selected by each address designated in each call.
Signals that have been code spread as above are digital modulated (QPSK) and then, power controlled at the
automatic gain control amplifier (AGC Amp). Then, they are converted into RF band by the frequency synthesizer
synchronizing these signals to proper output frequencies.
Transmit signals obtained pass through the duplexer filter and then, are sent out to the cell site via the antenna.

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4. Specification

4.1 General Specification

4.1.1 Transmit/Receive Frequency Interval :

1)CELLULAR : 45 MHz

2)PCS : 80 MHz

4.1.2 Number of Channels (Channel Bandwidth)

1)CELLULAR : 20 Channels

2) PCS : 48 Channels

4.1.3 Operating Voltage : DC 3.3~4.2V

4.1.4 Battery Power Consumption : DC 3.7V

MAX POWERIDLESLEEP

700 mA (24 dBm)110~180mA1.1 mA CELLULAR
700 mA (24 dBm)120~180 mA1.1 mAPCS

4.1.5 Operating Temperature : -0°C ~ +60°C

4.1.6 Frequency Stability

1)CDMA : ±0.5PPM

2)PCS : ±0.1PPM

4.1.7 Antenna : Press Type (PIFA), 50

4.1.8 Size and Weight

1)Size : 101.87(H) * 52(W) * 14.95(D) mm

2)Weight : 126.8 g (Approximately with standard battery)

4.1.9 Channel Spacing

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1)CELLULAR : 1.25MHz

2)PCS: 1.25 MHz

4.1.10 Battery Type, Capacity and Operating Time.

Standby Time

Unit = Hours : Minutes

Standard (800mAh)

About 165 Hours (SCI=2)CELLULAR
About 165 Hours (SCI=2)PCS

Talk time

140 Minutes (-92dBm input)CELLULAR
140 Minutes (-92dBm input)PCS

4.2 Receive Specification

4.2.1 Frequency Range

CELLULAR : 869.820 MHz ~ 893.190 MHz
PCS : 1930 MHz ~ 1990 MHz
GPS : 1575.42 MHz

4.2.2 Local Oscillating Frequency Range :

CELLULAR : 1738.08MHz ~ 1787.94MHz
PCS : 1715.56MHz ∼ 1768.89MHz
GPS : 3150.84MHz

4.2.3 Sensitivity

CELLULAR : -104dBm (C/N 12dB or more)
PCS : -104dBm (C/N 12dB or more)
GPS : -148.5dBm (without SA mode)

4.2.4 Selectivity

CELLULAR : 3dB C/N Degration (With Fch±1.25 kHz : -30dBm)
PCS : 3dB C/N Degration (With Fch±1.25 kHz : -30dBm)

4.2.5 Spurious Wave Suppression : Maximum of -80dB

4.2.6 CDMA Input Signal Range

Dynamic area of more than -104~ -25 dB: 79dB at the 1.23MHz band.

4.3 Transmit Specification

4.3.1 Frequency Range

CELLULAR : 824.820MHz ~ 848.190MHz
PCS : 1850 MHz ~ 1910 MHz

4.3.2 Output Power

CELLULAR : 0.224W
PCS: 0.224W

4.3.3 Interference Rejection

Single Tone : -30dBm at 900 kHz (CELLULAR), -30dBm at 1.25MHz(PCS)
Two Tone : -43dBm at 900 kHz & 1700kHz(CELLULAR), -43dBm at 1.25 MHz & 2.05 MHz (PCS)

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4.3.11 CDMA TX Frequency Deviation :

1) CELLULAR: +300Hz or less

2) PCS: ± 150Hz

4.3.12 CDMA TX Conducted Spurious Emissions

1) CELLULAR: 900kHz : - 42 dBc/30kHz below

1.98MHz : - 54 dBc/30kHz below

2) PCS: 1.25MHz: - 42 dBc/30kHz below

1.98MHz : - 50 dBc/30kHz below

4.3.13 CDMA Minimum TX Power Control

1) CELLULAR: - 50dBm below

2) PCS: -50dBm below

4.4 MS (Mobile Station) Transmitter Frequency

4.4.1 CELLULAR mode

1011

29

70
111
152
193
234
275
316
363

4.4.2 PCS mode

Ch #

Center Freq. (MHz)Ch #Center Freq. (MHz)Ch #

824.640

825.870

827.100

828.330

829.560

830.790

832.020

833.250

834.480

835.890

Ch #Center Freq

(MHz)

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404
445
486
527
568
609
650
697
738
779

Ch #Center Freq

(MHz)

837.120

838.350

839.580

840.810

842.040

843.270

844.500

845.910

847.140

848.370

Center Freq

(MHz)

1891.25 8251871.25 4251851.25 25

1892.50 8501872.50 4501852.50 50

1893.75 8751873.75 4751853.75 75

1895.00 9001875.00 5001855.00 100

1896.25 9251876.25 5251856.25 125

1897.50 9501877.50 5501857.50 150

1898.75 9751878.75 5751858.75 175

4.5 MS (Mobile Station) Receiver Frequency

4.5.1 CELLULAR mode

1900.00 10001880.00 6001860.00 200

1901.25 10251881.25 6251861.25 225

1902.50 10501882.50 6501862.50 250

1903.75 10751883.75 6751863.75 275

1905.00 11001885.00 7001865.00 300

1906.25 11251886.25 7251866.25 325

1907.50 11501887.50 7501867.50 350

1908.75 11751888.75 7751868.75 375

Center Freq. (MHz)Ch. #Center Freq. (MHz)Ch. #

1011

29

70
111
152
193
234
275
316
363

4.5.2 PCS mode

869.640

870.870

872.100

873.330

874.560

875.790

877.020

878.250

879.480

880.890

Ch #Center Freq

(MHz)Ch #

404
445
486
527
568
609
650
697
738
779

Ch #Center Freq

(MHz)

882.120

883.350

884.580

885.810

887.040

888.270

889.500

890.910

892.140

893.370

Center Freq

(MHz)

1971.25 8251951.25 4251931.25 25

1972.50 8501952.50 4501932.50 50

1973.75 8751953.75 4751933.75 75

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1975.00 9001955.00 5001935.00 100

1976.25 9251956.25 5251936.25 125

1977.50 9501957.50 5501937.50 150

1978.75 9751958.75 5751938.75 175

1980.00 10001960.00 6001940.00 200

1981.25 10251961.25 6251941.25 225

4.5.3 GPS mode : 1575.42 MHz

4.5.4 Bluetooth mode : 2400 MHz ~ 2483.5 MHz

4.6 AC Adaptor : See Appendix

4.7 Cigar Lighter Charger : See Appendix

1982.50 10501962.50 6501942.50 250

1983.75 10751963.75 6751943.75 275

1985.00 11001965.00 7001945.00 300

1986.25 11251966.25 7251946.25 325

1987.50 11501967.50 7501947.50 350

1988.75 11751968.75 7751948.75 375

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5. Installation

5.1 Installing a Battery Pack

1) The Battery pack is keyed so it can only fit one way. Align the groove in the battery pa ck with the rail on the back
of the phone until the battery pack rests flush with the back of the phone.

2) Slide the battery pack forward until you hear a “click”, which locks the battery in place.

5.2 For Adapter Use

1) Plug the adapter into a wall outlet. The adapter can be operated from a 110V source. When AC power is connected
to the adapter.

2) Insert the adapter IO plug into the phone with the installed battery pack.
Red light indicates battery is being charged.. Green light indicates battery is fully charged.

5.3 For Mobile Mount

5.3.1 Installation Position

In order to reduce echo sound when using the Hands-Free Kit, make sure that the speaker and microphone are not
facing each other and keep microphone a generous distance from the speaker.

5.3.2 Cradle Installation

Choose an appropriate flat surface where the un it will not interface with driver’s movement or passenger’s comfort.
The driver/user should be able to access the phone with ease. Using the four self-tapping screws provided, mount the
supplied bracket on the selected area. Then with the four machine screws provided, mount the counterpart on the
reverse side of the reverse side of the cradle. Secure the two brackets firmly together by using the two bracket joint
screws provide. The distance between the cradle and the interface box must not exceed the length of the main cable.

5.3.3 Interface Box

Choose an appropriate flat surface ( somewhere under the dash on the passenger side is preferred ) and mount the IB
bracket with the four self-tapping screws provided. Clip the IB into the IB bracket.

5.3.4. Microphone Installation

Install the microphone either by clipping I onto the sunvisor (driver’s side) or by attaching it to door post (driver’s
side), using a velcro adhesive tape (not included).

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5.3.5 Cable Connections

5.3.5.1 Power and Ignition Cables

Connect the red wire to the car battery positive terminal and the black wire to the car ground. Connect the green wire
to the car ignition sensor terminal. ( In order to operate HFK please make sure to connect green wire to ignition
sensor terminal.) Connect the kit’s power cable connector to the interface box power receptacle.

5.3.5.2 Antenna Cable Connection

Connect the antenna coupler cable connector from the cradle to the external antenna connector. ( Antenna is not
included.)

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CHAPTER 2. NAM Input Method

CHAPTER 2. NAM Input Method

(Inputting of telephone numbers included)

(Inputting of telephone numbers included)

1. NAM Programming Method and Telephone Number Input Method

1. Press ##2342# (##CDG2#)

2. Enter Service Code “000000”.

3. You can see following Menu

4. Press “1” key or Touch ‘Service Program’ list.
You can see following submenus.

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4-1) Press “1” key or Touch ‘Reset Phone’ list.
You can reset the phone

4-2) Press “2” key or Touch ‘Mobile Phone #’ list.

Input Mobile Phone Number and press softkey “OK” to save the change.
Press softkey “Í” to go back to the list.

4-3) Press “3” key or Touch ‘Home SID’ list.

Input the Home SID and press softkey “OK” to save the change.
Press softkey “Í” to go back to the list.

4-4) Press “4” key or Touch ‘Advanced’ list.
There are eleven submenus as below.

4-4.1) Press “1” key or Touch ‘MCC’ list.

Input the Mobile Country Code and press softkey “OK” to save the change.
Press softkey “Í” to go back to the list.

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4-4.2) Press “2” key or Touch ‘NMSI’ list.

Input the NMSI and press softkey “OK” to save the change.
Press softkey “Í” to go back to the list.

4-4.3) Press “3” key or Touch ‘True MCC’ list.

Input the True MCC and press softkey “OK” to save the change.
Press softkey “Í” to go back to the list.

4-4.4) Press “4” key or Touch ‘True IMSI NMSI’ list.

Input the True IMSI NMSI and press softkey “OK” to save the change.
Press softkey “Í” to go back to the list.

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4-4.5) Press “5” key or Touch ‘Home NID’ list.

Input the Home NID and press softkey “OK” to save the change.
Press softkey “Í” to go back to the list.

4-4.6) Press “6” key or Touch ‘Home Sys Reg’ list.

Select one what you want and touch it.
Press softkey “Í” to go back to the list.

4-4.7) Press “7” key or Touch ‘Forn SID Reg’ list.

Select one what you want and touch it.
Press softkey “Í” to go back to the list.

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4-4.8) Press “8” key or Touch ‘Forn NID Reg’ list.

Select one what you want and touch it.
Press softkey “Í” to go back to the list.

4-4.9) Press “9” key or Touch ‘CDMA Preferred CH’ list.

Select one what you want to edit, and touch it.
Press softkey “Í” to go back to the list.

4-4.10) Press “0” key or Touch ‘Slot Cycle Idx’ list.

Input the Slot Cycle and press softkey “OK” to save the change.
Press softkey “Í” to go back to the list.

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4-4.11) Press “*” key or Touch ‘Acc Ovld Class’ list.

You can see the Access Overload Class that is automatically set accord ing to IMSI_M
Press softkey “Í” to go back to the list.

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CHAPTER 3. Circuit Description

CHAPTER 3. Circuit Description

1. RF Transmit/Receive Part

1.1 Overview

The TX and RX part employs the Direct-Conversion system. The TX and RX frequencies are respectively

824.04~848.97 and 869.04~893.97 for cellular and 1850~1910 and 1930~1990 for PCS. The block diagram is shown
in [Figure 1-1]. CDMA RF signals received through the antenna are separated by the Diplexer.
RF Signal fed into the low noise amplifier in RFR6500(LNA) through the duplexer. Then, they are fed into Mixer in
RFR6500. In RFR6500, the RF signal is changed into baseband signal directly. Then, this signal is changed into
digital signal by the analog to digital converter (ADC, A/D Converter), and the digital circuit part of the
MSM(Mobile Station Modem) 6500 processes the data from ADC. The digital processing part is a demodulator.
In the case of transmission, RFT6150 receives OQPSK-modulated analog signal from the MSM6500.
The RFT6150 connects directly with MSM6500 using an analog baseband interface. In RFT6150, the baseband
quadrature signals are upconverted to the Cellular or PCS frequency bands and amplified to provide signal drive
capability to the power amp.
After that, the RF signal is amplified by the Power Amp in order to have enough power for radiation. Finally, the RF
signal is sent out to the cell site via the antenna after going through the duplexer.

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[Figure 1-1] RF Block Diagram of CX830

DP1000

U1001

F1000

F1002

F1001

U1006

U1009

F1003

U1008

F1004

U1007

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1.2 Description of RX Part Circuit

1.2.1 Quintiplexer(DP1000)

The Quintplexer combines PCS, and Cellular duplexer functions with a GPS filter. Each duplexer consists of the Rx

bandpass filter (BPF) and the Tx BPF which has the function of separating Tx and Rx signals in the full duplex
system for using the common antenna. The Tx part BPF is used to suppress noises and spurious out of the Tx
frequency band. The Rx BPF is used to receive only Rx signal coming from the antenna, which is usually called
preselector. It’s main function is to limit the bandwidth of spectrum reaching the LNA and mixer, attenuate receiver
spurious response and suppress local oscillator energy. As a result frequency sensitivity and selectivity of mobile
phone increase. The specification of LG-CX830 quintplexer is described below ;

z PCS Duplexer

Tx to Rx (min)RxTx

Pass Band

z Cellular Duplexer

Pass Band

z GPS Filter

1930~1990 MHz1850~1910 MHz

3.2dB max3.0dB maxInsertion Loss
12dB min9.5dB minReturn Loss

45dB min (1930~1990MHz)Attenuation

60dB min (824~849MHz)48dB min (869~894MHz)Attenuation

55dB min

(1850~1910MHz)

869~894 MHz824~849MHz

2.5dB max2.0dB maxInsertion Loss
12dB min12dB minReturn Loss

60dB (1850~1910MHz)

50dB (1930~1990MHz)

Tx to Rx (min)RxTx

60dB (824~849MHz)
50dB (869~894MHz)

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UNITMIN.TYP.MAX.

dB2.0Insertion Loss
dB9Return Loss
dB40 ~ 46ISOLATION

1.2.3 RFR6500 – LNA part (U1006)

The RFR6500 has cellular, and PCS LNA, respectively. The characteristics of Low Noise Amplifier (LNA) are low
noise figure, high gain, high intercept point and high reverse isolation. The frequency selectivity characteristic of
mobile phone is mostly determined by LNA.
The specification of CX830 LNA is described below:

UnitsHigh gainMiddle gainLow gainParameter

PCSCellularPCSCellularPCSCellular

dB1514-33-20-19Gain
dB1.11.364.52020Noise Figure

dBm371051010Input IP3

1.2.4 GPS LNA(U1001)

The characteristics of Low Noise Amplifier (LNA) are low noise figure, high g ain, high intercept p oint and high
reverse isolation. The frequency selectivity c haracteristic of mobile phone is mostly determined by LNA.
The specification of CX830 GPS LNA is described below

UnitsGPS BandParameter

dB14.3Gain

dB0.8Noise Figure
dBm1.81dB compression point
dBm+4.7IIP3

1.2.5 RX RF SAW FILTER(F1001, F1002)

The main function of RX RF SAW filter is to attenuate mobile phone spurious frequency, attenuate noise amplified
by the LNA and suppress second harmonic originating in the LNA.

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1.2.6 RFR6500 - Down-converter Mixers part (U1006)

The RFR6500 device performs signal down-conversion for Cellular, PCS and GPS tri-band applications. It contains
all the circuitry (with the exception of external filters) needed to support conversion of received RF signals to Base­band signals. The three down-converting Mixers (Cellular, PCS and GPS), and a programmable PLL for generating
RX LO frequency and an RX LO Buffer Amplifier and RX Voltage Controlled Oscillator. The GPS LNA & mixers
offer the most advanced and integrated CDMA RX solution designed to meet cascaded Noise Figure (NF) and Third­order Intercept Point (IIP3) requirements of IS-98D and J-STD-018 specifications for Sensitivity, Two-Tone Inter­modulation, and Single-tone Desensitization.
Operation modes and band selection are specially controlled from the Mobile Station Modem
MSM6500.
The specification of CX830 Mixers is described below:

UnitsHigh gainLow gainParameter

PCSCellularPCSCellular

dB127.92725Noise Figure

dBm44-11-5Input IP3

dBm56563030Input IP2

1.3 Description of Transmit Part Circuit

1.3.1 RFT6150 (U1007)

The RFT6150 Base-band to RF Transmit Processor performs all TX signal-processing functions required between
digital Base-band and the Power Amplifier Modulator (PAM). The Base-band quadrate signals are up-converted to
the Cellular or PCS frequency bands and amplified to provide signal drive capability to the PAM. The RFT6100
includes mixers for up-converting analog Base-band to RF, a programmable PLL for generating TX LO frequency a
TX LO Buffer Amplifier and TX Voltage Controlled Oscillator, cellular and PCS driver amplifiers and TX power
control through an 85 dB VGA. As added benefit, the single sideband up-conversion eliminates the need for a band
pass filter normally required between the up-converter and driver amplifier.

I, I/, Q and Q/ signals proceed from the MSM6500 to RFT6150 are analog signal. In CDMA mode, These signals are
modulated by Offset Quadrature Phase Shift King (OQPSK). I and Q are 90 deg. out of phase, and I and I/ are 180
deg. The mixers in RFT6150 converts baseband signals into RF signals. After passing through the upconverters, RF
signal is inputted into the Power AMP.

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zRFT6150 Cellular and PCS CDMA RF Specifications

UnitsMax.Type.Min.ConditionParameter

Rated Output Power

Min Output Power

RX band noise power

ACPR

1.3.2 Power Amplifier(U1008, U1009)

The Dual power amplifier that can be used in the PCS and CDMA mode has linear amplification capability and high
efficiency. For higher efficiency, it is made up of one MMIC (Monolithic Microwave Integrated Circuit) for which
RF input terminal and internal interface circuit are integrated onto one IC after going thro ugh the AlGaAs/GaAs HBT
(heterojunction bipolar transistor) process. The module of power amplifier is made up of an output end interface
circuit including this MMIC. The maximum power that can be inputted through the input terminal is +10dBm and
conversion gain is about 26.5dB. RF transmit signals that have been amplified through the power amplifier are sent to
the duplexer.
.

Average CDMA Cellular

Average CDMA PCS

Average CDMA Cellular

Average CDMA PCS

CDMA Cellular

CDMA PCS

Cellular: Fc±885kHz

PCS : Fc±1.25MHz

7
9

-75

-75

-136

-133

-56

-57

dBm
dBm

dBm
dBm

dBm/Hz

dBc/30kHz

1.4 Description of Frequency Synthesizer Circuit

1.4.1 Voltage Control Temperature Compensation Crystal Oscillator (VCTCXO, X1000)

The temperature variation of mobile phone can be compensated by VCTCXO. The reference frequency of a mobile
phone is 19.2 MHz. The receiver frequency tuning signals called TRK_LO_ADJ from MSM as 0.5 V~2.5 V DC via
R and C filter in order to generate the reference frequency of 19.2 MHz and input it into the frequency synthesizer.
Frequency stability depending on temperature is ±2.0 ppm.

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2. Digital/Voice Processing Part

2.1 Overview

The digital/voice processing part processes the user's commands and processes all the digital and voice signal
processing in order to operate in the phone. The digital/voice processing part is made up of a main keypad/touch
keypad/LCD, receptacle part, voice processing part, mobile station modem part, memory part, and power supply part.

2.2 Configuration

2.2.1 Keypad/LCD and Receptacle Part

This is used to transmit keypad signals to MSM6500. It is made up of a keypad backlight part that illuminates the
keypad, LCD part that displays the operation status onto the screen, and a receptacle that receives and sends out voice
and data with external sources.

2.2.2 Voice Processing Part

The voice processing part is made up of an audio codec used to convert MIC signals into digital voice signals and
digital voice signals into analog voice signals, amplifying part for amplifying the voice signals and sending them to
the ear piece, amplifying part that amplifies ringer signals coming out from MSM6500, and amplifying part that
amplifies signals coming out from MIC and transferring them to the audio processor.

2.2.3 MSM (Mobile Station Modem) 6500 Part

MSM is the core elements of CDMA terminal and carries out the functions of CPU, encoder, interleaver,
deinterleaver, Viterbi decoder, Mod/Demod, and vocoder.

2.2.4 Memory Part

The memory part is made up of a NAND Flash memory and a SDRAM for storing data.

2.2.5 Power Supply Part

The power supply part is made up of circuits for generating various types of power, used for the digital/voice
processing part.

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2.3 Circuit Description

2.3.1 Keypad/LCD and Receptacle Part

Once the main keypad is pressed, the key signals are sent out to MSM6500 for processing. Touch keypad is pressed,
I2C and Ack signals of U101(touch IC) are sent out to MSM6500 for processing. In addition, when the key is pressed,
the keypad/LCD lights up through the use of 19 LEDs. The terminal status and operation are displayed on the screen
for the user with the characters and icons on the LCD.
Moreover, it exchanges audio signals and data with external sources through the receptacle, and then receives power
from the battery or external batteries.

2.3.2 Audio Processing Part

MIC signals are amplified through OP AMP, inputted into the audio codec (included in MSM6500) and converted
into digital signals. Oppositely, digital audio signals are converted into analog signals after going through the audio
codec. These signals are amplified at the audio amplifier and transmitted to the ear-piece. The signals from
MSM6500 activate the ringer by using signals generated in the timer in MSM6500.

2.3.3 MSM Part

MSM6500 is the core element of CDMA system terminal that includes ARM926EJ-S microprocessor core. It
supports both CDMA and Digital FM, operating in both the cellular and PCS spectrums. The subsystems within the
MSM6500 include a CDMA processor, a DFM processor, a multi-standard Vocoder, an integrated CODEC with
earpiece and microphone amplifiers, general-purpose ADC for subsystem monitoring, an ARM926EJ-S
microprocessor, and an RS-232 serial interfaces supporting forward and reverse link MDR data communications of

230.4 Kbps simultaneously. And it also contains complete digital modulation and demodulation systems for both
CDMA and AMPS cellular standards, as specified in IS-95-A/B/C.
In MSM, coded symbols are interleaved in order to cope with multi-path fading. Each data channel is scrambled by
the long code PN sequence of the user in order to ensure the confidentiality of calls. Moreover, binary quadrature
codes are used based on Walsh functions in order to discern each channel. Data created thus are 4-phase modulated
by one pair of Pilot PN code and they are used to create I and Q data.
When received, I and Q data are demodulated into symbols by the demodulator, and then de-interleaved in reverse to
the case of transmission. Then, the errors of data received from Viterbi decoder are detected and corrected. They are
voice-decoded at the Vocoder in order to output digital voice data.

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