LG ELECTRONICS LGC800W SINGLE-BAND CELLULAR CDMA PHONE User Manual SVC Manual 800W

LG Electronics, Inc. SINGLE-BAND CELLULAR CDMA PHONE SVC Manual 800W

Contents

Service Manual

1 LG Information & Communications, Ltd.- 1 -Features of Mobile Subscriber Radio Telephone Set(LGC-800W Type)1. Wave Type • Digital : G7W2. Frequency Scope • Send Frequency : 824.820~848.190MHz • Receive Frequency : 869.820~893.190MHz3. Rated Output • 0.2W4. Output Conversion Method : This is possible by correcting the key board channel.5. Voltage and Current Value of Termination Part Amplifier(Catalogue included)Product Type Name Voltage Current PowerPWR AMP RF2132 5.0V 400mA 0.63W6. Functions of Major Semi-ConductorsClassification Function MSM3000-PBGA Terminal operation control and digital signal processing FLASH MEMORY & STATIC RAM(MB84VA2103-10P8)Flash Memory (16Mbit) Õ Storing of terminal operation programSRAM (2Mbit) Õ Temporary storing of the data created while busy IFT3000/IFR3000 Converting IF signal into baseband signal and analog signal into digital signal7. Frequency Stability • ¡¾0.5PPM
2 LG Information & Communications, Ltd.- 2 - CDMA PORTABLE CELLULAR PHONE LGC-800W SERVICE MANUAL
LGC-800W LG Information & Communications, Ltd. - 1 -Table of Contents General Introduction .............................................................................................................................................................. 2CHAPTER 1. System Introduction 1. System Introduction ................................................................................................................................... 3 2. Features and Advantages of CDMA Mobile Phone .................................................................................... 4 3. Structure and Functions of CDMA Mobile Phone ..................................................................................... 7 4. Specification ............................................................................................................................................... 8 5. Installation ................................................................................................................................................ 13CHAPTER 2. NAM Input Method(Inputting of telephone numbers included) 1. Telephone Number Input Method ............................................................................................................ 13 2. NAM Program Method ............................................................................................................................ 16CHAPTER 3. Circuit Description 1. RF Transmitter and Receiver ................................................................................................................ 17 2. Digital/Voice Processor .......................................................................................................... 24 CHAPTER 4. Trouble Shooting ............................................................................................................................................ 28CHAPTER 5. Test Proceduce ............................................................................................................................................ 34 Appendix ............................................................................................................................................ 35 1. Assembly and Disassembly Diagram 2. Block & Circuit Diagram 3. Part List 4. Component Layout 5. Accessories - Desktop Charger - Travel Charger - Cigar Lighter Charger - Hands Free Kit - Data Cable 6. WLPST ( LGIC Product Support Tool For Win95 )
LGC-800W LG Information & Communications, Ltd. - 2 -The LGC-800W cellular phone is a digital cellular phone working in CDMA (Code Division Multiple Access)mode. DSSS (Direct Sequence Spread Spectrum) mode which is used in military is applied to CDMA type digitalmode.This feature enables the phone to keep communication from being crossed and one frequency channel to be usedby multiple users in the same specific area, resulting that it increases the capacity 10 times more compared withthat in the analog mode currently used.Soft/Softer Handoff, Hard Handoff, and Dynamic RF power Control technologies are combined into this phoneto reduce the call drop in a middle of talking over phone.CDMA digital cellular network consists of MSC (Mobile Switching Office), BSC (Base Station Controller), BTS(Base station Transmission System), and MS (Mobile Station). Communication between MS and BTS isdesigned to meet the specification of IS-95A (Common Air Interface). MS meets the specifications of the below : - IS-95A ( Common Air Interface ) : Protocol between MS and BTS - IS-96A ( Vocoder ) : Voice signal coding - IS-98 : Basic MS functions - IS-126 : Voice loopback - IS-99 : Short Message Service, Async Data Service, and G3 Fax ServiceLGC-800W is composed of transceiver, desktop charger, two Li-Ion Battery (900mAh), hands-free kit, travelcharger, Data Cable. Hands-free kit in digital mode is designed to be operated in full duplex. General Introduction
LGc-320/330W3 LG Information & Communications, Ltd.- 3 -1. System Introduction1.1 CDMA AbstractThe cellular system has a channel hand-off function that is used for collecting the information on the locationsand movements of radio mobile telephones from the cell site by automatically controlling several cell site throughthe setup of data transmission routes and thus, enabling one switching system to carry out the automatic remoteadjustment. This is to maintain continuously the call state through the automatic location confirmation andautomatic radio channel conversion when the busy subscriber moves from the service area of one cell site to thatof another by using automatic location confirmation and automatic radio channel conversion functions. The callstate can be maintained continuously by the information exchange between switching systems when the busysubscriber moves from one cellular system area to other cellular system area.In the cellular system, the cell site is a small-sized low output type and utilizes a frequency allocation system thatconsiders mutual interference, in an effort to reuse corresponding frequency from a cell site separated more thana certain distance. The analog cellular systems are classified further into an AMPS system, E-AMPS System,NMT system, ETACS system, and JTACS system depending on technologies used.Unlike the time division multiple access (TDMA) or frequency division multiple access (FDMA) used in theband limited environment, the Code Division Multiple Access(CDMA) system which is one of digital cellularsystems is a multi-access technology under the interference limited environment. It can process more number ofsubscribers compared to other systems (TDMA system has the processing capacity three times greater than theexisting FDMA system, whereas the capacity of CDMA system is about 12~15 times that of the existing system).CDMA system can be explained as follows: TDMA or SDMA can be used to enable each person to talkalternately or provide a separate room for each person when two persons desire to talk with each other at thesame time, whereas FDMA can be used to enable one person to talk in soprano, whereas the other in bass (one ofthe two talkers can carry out synchronization for hearing in case there is a bandpass filter function in the area ofthe hearer).Another method available is to make two persons to sing in different languages at the same time, space, andfrequency when wishing to let the audience hear the song without being confused. This is the characteristics ofCDMA.On the other hand, when employing the CDMA technology, each signal has a different pseudo-random binarysequence used to spread the spectrum of carrier. A great number of CDMA signals share the same frequencyspectrum. In the perspective of frequency area or time area, several CDMA signals are overlapped. Among thesetypes of signals, only desired signal energy is selected and received through the use of pre-determined binarysequence; desired signals can be separated and then, received with the correlator used for recovering thespectrum into its original state. At this time, the spectrums of other signals that have different codes are notrecovered into its original state and instead, processed as noise and appears as the self-interference of the system. CHAPTER 1. System Introduction
LGC-800W LG Information & Communications, Ltd. - 4 -2. Features and Advantages of CDMA Mobile Phone2.1 Various Types of DiversitiesWhen employing the narrow band modulation (30kHz band) that is the same as the analog FM modulationsystem used in the existing cellular system, the multi-paths of radio waves create a serious fading. However, inthe CDMA broadband modulation(1.25MHz band), three types of diversities (time, frequency, and space) areused 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 frequencydiversity can be obtained by spreading signal energy to more wider frequency band. The range of fading relatedto normal frequency is normally 200~300kHz and accordingly, serious effect can be avoided. Moreover, spacediversity (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 useof multi-signal processing device that receives a transmit signal having each different transmission delay time andthen, combines them. Third, it can be obtained through the multiple cell site connection (Soft Handoff) thatconnects the mobile station and more than two cell sites at the same time.2.2 Power ControlThe CDMA system utilizes the forward (from a base station to mobile stations) and backward (from the mobilestation to the base station) power control in order to increase the call processing capacity and obtain high-qualitycalls. In case the originating signals of mobile stations are received by the cell site in the minimum call qualitylevel (signal to interference) through the use of transmit power control on all the mobile stations, the systemcapacity can be maximized.If the signal 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 andaccordingly, the call quality of other subscribers is reduced unless the maximum accommodation capacity isreduced.In the CDMA system, forward power control, backward open loop power control, and closed loop power controlmethods are used. The forward power control is carried out in the cell site to reduce the transmit power onmobile stations less affected by the multi-path fading and shadow phenomenon and the interference of other cellsites when the mobile station is not engaged in the call or is relatively nearer to the corresponding cell site. Thisis also used to provide additional power to mobile stations having high call error rates, located in bad receptionareas or far away from the cell site.The backward open loop power control is carried out in a corresponding mobile station; the mobile stationmeasures power received from the cell site and then, reversely increases/decreases transmit power in order tocompensate channel changes caused by the forward link path loss and terrain characteristics in relation to themobile station in the cell site. By doing so, all the mobile office transmit signals in the cells are received by thecell site in the same strength.Moreover, the backward closed loop power control used by the mobile station to control power with thecommands issued out by the cell site. The cell site receives the signal of each corresponding mobile station andcompares this with the pre-set threshold value and then, issues out power increase/decrease commands to the
LGC-800W LG Information & Communications, Ltd. - 5 -corresponding mobile station every 1.25 msec (800 times per second).By doing so, the gain tolerance and the different radio propagation loss on the forward/backward link arecomplemented.2.3 Voice Encoder and Variable Data SpeedThe bi-directional voice service having variable data speed provides voice communication which employs voiceencoder algorithm having power variable data rate between the mobile telephone cell site and mobile station. Onthe other hand, the transmit voice encoder performs voice sampling and then, creates encoded voice packets to besent out to the receive voice encoder, whereas the receive voice encoder demodulates the received voice packetsinto voice samples.One of the two voice encoders described in the above is selected for use depending on inputted automaticconditions and message/data; both of them utilize four-stage frames of 9600, 4800, 2400, and 1200 bits persecond. In addition, this type of variable voice encoder utilizes adaptive threshold values when selecting requireddata rate. It is adjusted in accordance with the size of background noise and the data rate is increased to high rateonly when the voice of caller is inputted.Therefore, background noise is suppressed and high-quality voice transmission is possible under the environmentexperiencing serious noise. In addition, in case the caller does not talk, data transmission rate is reduced so thatthe transmission is carried out in low energy. This will reduce the interference on other CDMA signals and as aresult, improve system performance (capacity, increased by about two times).2.4 Protecting Call ConfidentialityCDMA signals have the function of effectively protecting call confidentiality by spreading and interleaving callinformation in broad bandwidth. This makes the unauthorized use of crosstalk, search receiver, and radio veryhard substantially. Also included is the encryption function on various authentication and calls specified in IS-95for the double protection of call confidentiality.2.5 Soft HandoffDuring the soft hand, the cell site already in the busy state and the cell site to be engaged in the call laterparticipate in the call conversion. The call conversion is carried out through the original call connection cell site,both cell sites, and then, new cell site. This method can minimize call disconnection and prevent the user fromdetecting the hand-off.2.6 Frequency Re-Use and Sector SegmentationUnlike the existing analog cellular system, the CDMA system can reuse the same frequency at the adjacent cell
LGC-800W LG Information & Communications, Ltd. - 6 -and accordingly, there is no need to prepare a separate frequency plan. Total interference generated on mobilestation signals received from the cell site is the sum of interference generated from other mobile stations in thesame cell site and interference generated from the mobile station of adjacent cell site. That is, each mobile stationsignal generates interference in relation to the signals of all the other mobile signals.Total interference from all the adjacent cell sites is the ratio of interference from all the cell sites versus totalinterference from other mobile stations in the same cell site (about 65%). In the case of directional cell site, onecell normally uses a 120¡Æsector antenna in order to divide the sector into three. In this case, each antenna isused only for 1/3 of mobile stations in the cell site and accordingly, interference is reduced by 1/3 on the averageand the capacity that can be supported by the entire system is increased by three times.2.7 Soft CapacityThe subscriber capacity of CDMA system is flexible depending on the relation between the number of users andservice classes. For example, the system operator can increase the number of channels available for use duringthe busy hour despite the drop in call quality. This type of function requires 40% of normal call channels in thestandby mode during the handoff support, in an effort to avoid call disconnection resulting from the lack ofchannels.In addition, in the CDMA system, services and service charges are classified further into different classes so thatmore transmit power can be allocated to high class service users for easier call set-up; they can also be givenhigher priority of using hand-off function than the general users.
LGC-800W LG Information & Communications, Ltd. - 7 -3. Structure and Functions of CDMA Mobile PhoneThe mobile station of CDMA system is made up of a radio frequency part and logic/control (digital) part. Themobile station is fully compatible with the existing analog FM system. The mobile station antenna is connectedwith the transmitter/receiver via a duplexer filter so that it can carry out the transmit/receive function at the sametime.The transmit frequency is the 25MHz band of 824~849MHz, whereas the receive frequency is the 25MHz bandof 869~894MHz. The transmit/receive frequency is separated by 45MHz. The RF signal from the antenna isconverted into intermediate frequency(IF) band by the frequency synthesizer and frequency down converter andthen, passes the bandpass SAW filter having the 1.25MHz band. IF output signals that have been filtered fromspurious signal are converted into digital signals via an analog-to-digital converters(ADC) and then, sent outrespectively to 5 correlators in each CDMA de-modulator. Of these, one is called a searcher whereas theremaining 4 are called data receiver(finger). Digitalized IF signals include a great number of call signals thathave 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 ofcorrelation detection process. Then, other signals obtain processing gain by not increasing the ratio. The carrierwave of pilot channel from the cell site located most adjacently is demodulated in order to obtain the sequence ofencoded data symbols. During the operation with one cell site, the searcher searches out multi-paths inaccordance with terrain and building reflections. On three data receivers, the most powerful four paths areallocated for the parallel tracing and receiving. Fading resistance can be improved a great deal by obtaining thediversity combined output for de-modulation. Moreover, the searcher can be used to determine the most powerfulpath from the cell sites even during the soft handoff during the two cell sites. Moreover, four data receivers areallocated in order to carry out the de-modulation of these paths. Data output that has been demodulated changethe data string in the combined data row as in the case of original signals(deinterleaving), and then, are de-modulated by the forward error correction decoder which uses the Viterbi algorithm.On the other hand, mobile station user information sent out from the mobile station to the cell site pass throughthe digital voice encoder via a mike. Then, they are encoded and forward errors are corrected through the use ofconvolution encoder. Then, the order of code rows is changed in accordance with a certain regulation in order toremove any errors in the interleaver. Symbols made through the above process are spread after being loaded ontoPN 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 theautomatic gain control amplifier (AGC Amp). Then, they are converted into RF band by the frequencysynthesizer 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.
LGC-800W LG Information & Communications, Ltd. - 8 -4. Specification4.1 General Specification4.1.1 Transmit/Receive Frequency Interval : 45 MHz4.1.2 Number of Channels (Channel Bandwidth) : 20 CH4.1.3 Operating Voltage : DC 3.0V4.1.4 Battery Power Consumption : DC 3.5VSLEEP IDLE MAX POWERCDMA 2 mA120 mA 800 mA (24 dBm)4.1.5 Operating Temperature : -30° ~ +60°4.1.6 Frequency Stability : ¡¾0.5PPM4.1.7 Antenna : Retractable Type (Herical+Whip), 50 Ω4.1.8 Size and Weight1) Size : 105545519.9§§2) Weight : 104g (About)4.1.9 Channel Spacing : 1.25MHz4.1.10 Battery Type, Capacity and Orerating Time. Unit = Hours : MinutesState Retracted (900mAh)Stand-By Time 150Talk Time 2:204.2 Receive Specification4.2.1 Frequency Range : 869.82MHz ~ 893.190MHz 4.2.2 Local Oscillating Frequency Range : 966.88MHz¡¾12.5MHz4.2.3 Intermediate Frequency : 85.38MHz4.2.4 Sensitivity : -104dBm(C/N 12dB or more)
LGC-800W LG Information & Communications, Ltd. - 9 -4.2.5 Selectivity : 3dB C/N Degration(With Fch¡¾1.25 kHz : -30dBm)4.2.6 Spurious Wave Suppression : Maximum of -80dB4.2.7 CDMA Input Signal Range • Dynamic area of more than -104~ -25 dB : 79dB at the 1.23MHz band.4.3 Transmit Specification4.3.1 Frequency Range : 824.820MHz ~ 848.190MHz4.3.2 Local Oscillating Frequency Range : 966.88 MHz¡¾12.5 MHz4.3.3 Intermediate Frequency : 130.38 MHz4.3.4 Output Power : 0.2W4.3.5 Interference Rejection 1) Single Tone : -30dBm at 900 kHz 2) Two Tone : -43dBm at 900 kHz & 1700kHz4.3.6 CDMA TX Frequency Deviation : +300Hz or less4.3.7 CDMA TX Conducted Spurious Emissions • 900kHz : - 42 dBc/30kHz below • 1.98MHz : - 54 dBc/30kHz below4.3.8 CDMA Minimum TX Power Control : - 50dBm below4.4 MS (Mobile Station) Transmitter FrequencyFA NO. CH.NO. CENTER FREQUENCY FA NO. CH.NO. CENTER FREQUENCY1234567891010112970111152193234275316363824.640 MHz825.870 MHz827.100 MHz828.330 MHz829.560 MHz830.790 MHz832.020 MHz833.250 MHz834.480 MHz835.890 MHz11121314151617181920404445486527568609650697738779837.120 MHz838.350 MHz839.580 MHz840.810 MHz842.04 MHz843.270 MHz844.500 MHz845.910 MHz847.140 MHz848.370 MHz
LGC-800W LG Information & Communications, Ltd. - 10 -4.5 MS (Mobile Station) Receiver FrequencyFA NO. CH.NO. CENTER FREQUENCY FA NO. CH.NO. CENTER FREQUENCY1234567891010112970111152193234275316363869.640 MHz870.870 MHz872.100 MHz873.330 MHz874.560 MHz875.790 MHz877.020 MHz878.250 MHz879.480 MHz880.890 MHz11121314151617181920404445486527568609650697738779882.120 MHz883.350 MHz884.580 MHz885.810 MHz887.04 MHz888.270 MHz889.500 MHz890.910 MHz892.140 MHz893.370 MHz4.6 Desktop Charger : See Appendix4.7 Travel Charger : See Appendix4.8 Cigar Lighter Charger : See Appendix4.9 Hands-Free Kit : See Appendix4.9 Data Cable : See Appendix
LGC-800W LG Information & Communications, Ltd. - 11 -5. Installation5.1 Installing a Battery Pack1) The Battery pack is keyed so it can only fit one way. Align the groove in the battery pack with the rail on theback 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 Desktop Charger Use1) Plug the charger into a wall outlet. The charger can be operated from either a 110V or a 220V source. WhenAC power is connected to the desktop charger, both the green and red LED’s blink once.2) Insert the phone with the installed battery pack or a spare battery pack into the individual battery pack slot.Red light indicates battery is being charged.. Green light indicates battry is fully charged.5.3 For Mobile Mount5.3.1 Installation PositionIn order to reduce echo sound when using the Hands-Free Kit, make sure that the speaker and microphone are notfacing each other and keep microphone a generous distance from the speaker.5.3.2 Cradle Installation Choose an appropriate flat surface where the unit will not interface with driver’s movement or passenger’scomfort. The driver/user should be able to access the phone with ease. Using the four self-tapping screwsprovided, mount the supplied braket on the selected area. Then with the four machine screws provided, mount thecounterpart on the reverse side of the reverse side of the cradle. Secure the two brackets firmly together by usingthe two bracket joint screws provide. The distance between the cradle and the interface box must not exceed thelength of the main cable.5.3.3 Interface BoxChoose an appropriate flat surface ( somewhere under the dash on the passenger side is preferred ) and mount theIB bracket with the four self-tapping screws provided. Clip the IB into the IB bracket.5.3.4. Microphone InstallationInstall the microphone either by cliiping I onto the sunvisor (driver’s side) or by attaching it to door post(driver’s side), using a velcno adhesive tape (not included).
LGC-800W LG Information & Communications, Ltd. - 12 -5.3.5 Cable Connections5.3.5.1 Power and Ignition CablesConnect the red wire to the car battery positive terminal and the black wire to the car ground. Connect the greenwire to the car ignition sensor terminal. ( In order to operate HFK please make sure to connect green wire toignition sensor terminal.) Connect the kit’s power cable connector to the interface box power receptacle.5.3.5.2 Antenna Cable ConnectionConnect the antenna coupler cable connector from the cradle to the external antenna connector. ( Antenna is notincluded.)
LGC-800W LG Information & Communications, Ltd. - 13 -1. Telephone Number Inputting MethodTelephone numbers can be inputted as follows in LGC-800W. • Press MENU+0 and then, press the password made up of six digits(Default:000000). • Press 6 when the menu is displayed as illustrated on the followi type. è • NAM1 Setting Õ NAM2 Setting. • Select one NAM and then, input as shown in the following diagram (registration required from NAM1).PHONEMODEL7SLOT CYCLEINDEX2[SAVE]NAM1.PHONE NUMBER0000000000NAM1.NAMEPOWER 017[SAVE][SAVE][SAVE] CHAPTER 2. NAM Input Method (Inputting of telephone numbers included)1 : Serv Mode ç2 : Pref. Mode 1 : Short NAM ç2 : Ext. NAM
LGC-800W LG Information & Communications, Ltd. - 14 -2. NAM Program MethodThe NAM inputting method of LGC-800W is as follows.After input Telephone Number as stage1 then you will see massage ask whether you will do NAM program ornot.Press more edit key.FUNCTION DEFAULT DESCRIPTIONSERVICE SECURITY CODE 000000 Enter Service Sec. codeNAM1 MOBILE COUNTRY CODE 450 Enter Mobile Country CodeNAM1 MOBILE NETWORK CODE 22 Enter Mobile Network CodeNAM1 CDMA SID 1 1700 Enter CDMA Home System I.D.#1NAM1 CDMA NID 1 1 Enter CDMA Network I.D.#1NAM1 CDMA SID 2 1700 Enter CDMA Home System I.D.#2NAM1 CDMA NID 2 2Enter CDMA Network I.D.#2NAM1 CDMA SID 3 1700 Enter CDMA Home System I.D.#3NAM1 CDMA NID 3 3Enter CDMA Network I.D.#3NAM1 CDMA SID 4 1700 Enter CDMA Home System I.D.#4NAM1 CDMA NID 4 65535 Enter CDMA Network I.D.#4NAM1 SYSTEM A PRIMARY CHAN 400 Enter System A Primary ChannelNAM1 SYSTEM B PRIMARY CHAN 400 Enter System B Primary ChannelNAM1 SYSTEM A SECONDARY CHAN 400 Enter System A Secondary ChannelNAM1 SYSTEM B SECONDARY CHAN 400 Enter System B Secondary Channel
LGC-800W LG Information & Communications, Ltd. - 15 -1. RF Transmitter and Receiver1.1 OverviewThe RF transceiver (transmitter and receiver) employs Super-Heterodyne system. The frequency ranges oftransmitter and receiver are 824.640~848.370 MHz and 869.640~893.370 MHz respectively. The block diagramof this mobile phone is shown in figure 1.RF signals received from the antenna are fed into the mixer through the duplexer. Mixer converts RF signals intointermediate frequency (IF) signals by mixing RF signals with signals from local Oscillator (VCO). IF signals aresent to AGC (Auto Gain Controller) contained in the IFR (Internediate Frequency Receiver) through bandpassfilter (BPF). The signals are converted to baseband signals and finally sent to MSM.In the case of transmission, IFT (Internediate Frequency Transmitter) receives modulated digital signals from theMSM and creates analog baseband signals using the digital/analog converter (DAC, D/A Converter). Basebandsignals are changed into IF siganls, and these signals are fed into Mixer after adjusting the gain with AGC in IFT.If signals are converted into RF signals in the Mixer, and the gain of signals are adjusted once more by RFAGC. RF signals are amplified by drive anmplifier and, thereafter, fed into Power Amplifier. Amplified signalsare sent out to the cell site via the antenna after going through the isolator and duplexer.Block Diagram of RF Tansmitter and Receiver Circuit CHAPTER 3. Circuit DescriptionRX, PLLIFT3000IFR3000MSM3000VCO/PLLDPXANTCPPAMCODECTXIFT/IFRISOPA
LGC-800W LG Information & Communications, Ltd. - 16 -1.2 Description of Receiver1.2.1 Duplexer (F103)The duplexer separates transmitted and received signals in order to be operated in full duplex mode usingcommon antenna.The duplexer consists of receive bandpass filter (BPF) and the transmit bandpass filter (BPF). The transmit BPFis used to suppress noises and to keep spurious waves of transmitter from entering receiver, which preventsreceiver sensitivity degradation. The receive BPF blocks the trnasmitted signals from entering the receiver end,which improves sensitivity characteristics and rejects image signals on IF signals.Insertion loss (IL) of transmit BPF is 3.6dB (Max), whereas IL of the receiver is 4.3dB (Max). The attenuation ofthe transmit BPF for receiving signals in is 43dB (Min), and is over 27 dB beyond 1.6GHz. The attenuation ofthe transmit BPF for transmitting signals is 50dB or more, and attenuation for local oscillating signal is at least30 dB.1.2.2 Low Noiser Amplifier (LNA) RF signals from Duplexer are fed into LNA through input matching circuit. The signals which were maximallyamplified to reduce noise pass through BPF and are sent to mixer. The noise figure of LNA is 1.5 dB and gain is19dB. The loss of image frequency rejection filter is 3dB (max), attenuation for transmitting signal (824-849MHz) is at least 25dB.1.2.3 MixerSignals from BPF are fed into input port of Mixer and mixed with local oscillating signal of UHF band, resultingin sum and difference signals. This is a double balnaced mixer, which is used to prevent received signaldistorsion resulting from the insertion of local signal into iuput and output port. When RF signals and local signalare mixed, two signals are made from the nonlinear characteristic of transistor. Among the two signals, thesignal of 85.38 MHz is selected. L, C circuit of balanced type improves the frequency selection characteristic byoperating as resonant circuit and matching circuit.The noise figure of Mixer and IF AMP is 6dB, and the conversion gain is 13dB±4.5dB.1.2.4 Intermediate Frequency Circuit Signals converted by mixer are sent to BPF which has at least 30 dB attenuation for outside band and improvessensitivity of receiver. IF signals of 85.38 MHz are amplified or attenuated by AGC according to the signallevel. The control range of AGC is ±45 dB. This is a compensating circuit to prevent sensivity degradation due tothe variation of received signal according to the position of mobile station.The signals from AGC circuit are sent to QPSK demodulator and converted baseband signals by mixer.
LGC-800W LG Information & Communications, Ltd. - 17 -Demodulated signals are sent to each lowpass filter of IFR.1.3 Description of IFT/IFR Transceiver IFT consists of AGC, Mixer, Buffer, Mode Controller, ADC ( Analog Digital Converter), and IFR consists ofAGC, IF VCO, Clock Distribution Circuit, QPSK Demodulator.1.3.1 Digital Conversion Circuit of CDMA Received SignalAfter frequency conversion, the frequency band of CDMA baseband is from 1 kHz to 630 kHz. CDMA basebandfilter defines signals over 750 kHz as unnecessary signals. Besides IF filter, this baseband filter improves theability to select correct signals from jamming effect due to unnecessary signals. I_OFFSET and Q_OFFSET arealso used to improve sensitivity by controlling DC offset of QPSK. This control signal is made in MSM of digitalcircuit. Analog I/Q baseband signals are converted to digital signals by two 4bit ADC. Digital signals are sent out at thefalling edge of 9.8304 MHz clock signal. The signal of 9.8304 MHz coming from CHIPx8 stems from VCTCXO(Voltage Controlled Temperature Compensated Oscillator), of which frequency is 19.68 MHz.1.3.2 Analog Conversion Ciruit of CDMA Transmitted SignalIFT receives digital baseband I/Q signals from MSM. 8bit I/Q data are sent into DAC (Digital Analog Converter)of B/B ASIC after they are multiplexed. Data are sent to I DAC at the rising edge, and sent to Q DAC at thefalling edge. I and Q data have time difference of 1/2 times of clock cycle.1.4 Description of Transmitter1.4.1 Modulation and AGC Circuit Modulation and AGC circuits consist of modulator, mixer, and AGC circuit and Upconverter.I/Q data are modulated to IF signals of 130.38 MHz. These signals are fed into AGC. AGC uses gain controlsignal, or TX_AGC_ADJ, for control of gain. Output signals of AGC are sent to the input port of Upconverter.Upconverter makes sum and difference signals by mixing IF signal with local oscillating signal of UHF band.Local oscillating signal made in PLL is divided into transmitter local signal and receiver local signal. When IFsignal and local signal are inserted into transistor, two mixed signals are made by the nonlinear characteristic oftransistor. Among the two signals, the signal of UHF (824.640~848.370 MHz) is sent out as main signal.1.4.2 Bandpass Filter of TransmitterOutput signal of Upconverter is sent to bandpass filter of transmitting band. This filter is SAW filter ( Surface
LGC-800W LG Information & Communications, Ltd. - 18 -Acoustic Filter), of which IL is at most 3.5 dB and attenuation for receving signal and local oscillating signal is atleast 30 dB. The siganl coming from BPF is sent to Power AMP.1.4.3 Power Amplifier and Power Detection CircuitRF signal which was filtered by the BPF is amplified at the Power Amplifier. After the signal passes throughIsolator and Duplexer , it is radited at the antenna to the base station. The ouput power is +24dBm. Poweramplifier is designed with GaAs FET. Amplified signal is feedbacked to MSM, modulation and AGC circucit for the detection and compensation ofouput power error which comes from the power rising due to temperature and from ripple due to mismatching.Rated Power of Isolator is 5 Watt and its isolation is at least 15dB. Without Isolator, Power amplifier can behurted by the reflection power. Isolator is, therefore, inserted between Power AMP and Duplex to prevent PAfailer. Duplexer uses dielectric filter which makes transmitted and received signals pass and other unnecessarysignals stop. IL at the receiving band is about 3.6 dB or less, and connected to antenna with RF cable.1.5 Frequency Conversion Circuit1.5.1 VCTCXO (Voltage Control Temperature Compensation Crystal Oscillator)VCTCXO is a source of clock signals. These signals are used for the UHF mixer, modulation anddemodulation, baseband reference clock. It is temperature compensated crystal oscillator and has stability of 2.5ppm at the operating temperature(-30°C~60°C). The variable frequency range according to the supply voltage is240 Hz. The DC supply voltage is 3 V.1.5.2 UHF Band MixerThis circuit consists of PLL (Phase Locked Loop), VCO of which center frequency is 967 MHz, Loop Filter.Reference frequency is 30 kHz. Local oscillating signal with 0 phase error is generated by comparing referencesignal with PLL input signal which is made by dividing the signal of VCO. This local signal is used commonlyfor both transmitter and receiver.2. Digital/Voice Processing Part2.1 OverviewThe digital/voice processing part processes the user's commands and all the digital and voice signal processing.The digital/voice processing part is made up of a keypad/LCD, receptacle part, voice processing part, mobile
LGC-800W LG Information & Communications, Ltd. - 19 -station modem, memory part, and power supply part.2.2 Configuration2.2.1 Keypad/LCD and Receptacle PartThis is used to transmit keypad signals to MSM3000. It is made up of a keypad backlight part that illuminates thekeypad, LCD part that displays the operation status onto the screen, and a receptacle that receives and sends outvoice and data with external sources.2.2.2 Voice Processing PartThe voice processing part is made up of an audio codec used to convert MIC signals into digital voice signalsand digital voice signals into analog voice signals, amplifying part for amplifying the voice signals and sendingthem to the ear piece, amplifying part that amplifies ringer signals coming from MSM3000, and amplifying partthat amplifies signals coming out from MIC and transferring them to the audio processor.2.2.3 MSM (Mobile Station Modem) 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 PartThe memory part is made up of a flash memory which stores program, SRAM which stores data, and EEPROM.2.2.5 Power Supply PartThe power supply part is made up of various power generating circuit.
LGC-800W LG Information & Communications, Ltd. - 20 -2.3 Circuit DescriptionRingerFLASHMemory&SRAMEEPROMReceptaclePowerSupplyAUDIOProcessorMSM3000EarpieceMICLCDKeypadBlock Diagram of Digital/Voice Processing Circuit2.3.1 Keypad/LCD and Receptacle PartWhen the keypad is pressed, the key signal is sent to MSM3000 for processing and 15 LEDs lights up thekeypad. The terminal status and operation are displayed on the screen of LCD for the user. Moreover, itexchanges audio signals and data with external sources through the receptacle. 2.3.2 Voice Processing PartMIC signals are amplified with OP AMP, inputted into the audio codec, and converted into digital signals. Then,they are inputted to MSM. In addition, digital audio signals coming from MSM are converted into analog signalsafter going through the audio codec. These signals are amplified at the audio AMP and transferred to the earpiece. Then, the signals of ringer activate the ringer by activating Q705 with signals generated in the timer inMSM.2.3.3 MSM PartMSM3000, which is U400, is the core element of CDMA system terminal. It is made up of a CPU, encoder,interleaver, deinterleaver, Viterbi decoder, MOD/DEM, and vocoder. Digital voice data are encoded withvariable-rate. They are, then, convolutionally encoded to detect and correct error. Coded symbols are interleavedin order to cope with multi-path fading. Each data channel is scrambled by the long code PN sequence of the userin order to ensure the confidentiality of calls. Moreover, binary quadrature codes based on Walsh functions areused in order to discern each channel. Created data are modulated to 4-phase with one pair of Pilot PN code and I
LGC-800W LG Information & Communications, Ltd. - 21 -and Q data are generated .In receiving, I and Q data are demodulated into symbols by the demodulator and then, de-interleaved in oppositeprocedure to the case of transmission. Digital Voice data are generated from Vocoder after detecting andcorrecting the error of Viterbi Decoder.2.3.4 Memory PartOperatin program is stored in the Flash memory, and nonerasable data such as unique phone nulber is stored inthe EEPROM. Other data generated in phone operation is temporarily stored in SRAM.2.3.5 Power Supply PartDC/DC Converter supplys 5 V to Power AMP, and regulators generate various DC voltage such as 3 V supplyused for RF/IF and Digital/Audio Processor. These DC/DC converter and regulators use 3.6 V battery.
LGC-800W LG Information & Communications, Ltd. - 22 -1. When power isn't "Turn On".STARTRecharge Batt.Batt. Volt< 3.6VYesNo Change U703 Voltage at16 pin of U703< 3.6VNoYes Voltage at9 pin of U703< 3.3VChange U605 Voltage at5 pin of U605< 3.3VChange Sub. BoardTurn On YesNoChange Main BoardChangeOld Sub. BoardYesYesNoYesNo2. When LCD isn't displayed.STARTRefer to [1]Circuit to supplypower nominal?YesNo Check pins of con972orReconnect con972LCD supplied power NoYesGoodLCD display?YesNoChange LCD CHAPTER 4. Trouble Shooting
LGC-800W LG Information & Communications, Ltd. - 23 -3. When Tx Audio (MIC) isn't transmitted.STARTSinewaveappear at 3 pinof U801YesNoChange MIC unitSetup Test modeSet Tx Audio unmuted andset path to L/T Audio outSupply 1kHz/-20dBmto L/T by AF Gen. Sinewaveappear at 40 pinof U802NoChange U802Change U801YesOperationNoYesGoodOperation Yes GoodNoChangeSub Board4. When Rx Audio (Speaker) isn't heard.STARTChange Earpiece unitSetup Test modeSet Rx Audio unmuted andset path to L/T Audio InSupply RF signal of -20dBmwith Dev. 8kHz at 1kHzSinewaveappear at 44 pinof U802NoYesNoChangeSub BoardOperationYesGood
LGC-800W LG Information & Communications, Ltd. - 24 -5. When Keytone isn't heard.STARTGoodKeytone heardat handset?YesNoSupply Powerto HandsetCheck signalat R976?Change EarpieceChangeMain BoardNoYesRectangularwave appear 5/8 pinof U971NoYesVoltageof U802= 3.3V ?Change U802NoYesChange U971YesRectangularwave appear 4 pinof U971Check Ext. RingAmbient circuitNo6. When Buzzer isn't rung.STARTPaging to Handsetwith HP8924CService option 1.Change Q803YesChange Main BoardNoCheck Q803V_H at Base Rect. waveat EmitterYesNo3.6Vat CollectorYesNoChange Q801
LGC-800W LG Information & Communications, Ltd. - 25 -7. When Tx carrier isn't transmitted.STARTSetup Test modewith DM* Mode offline-a* load-sync #ch* carrier on* satoff* set-attn 0Check BBA &Tx Attenuator circuit Tx IF freq.appear at 1/2 pinof U202YesNo Tx IF freq.appear at 1/2 pinof U201YesNoVoltageat 4/7 pin of U202 = 3.6VYesNoCheck U601 &Peripheral circuitVoltageat 8 pin of U202 = 2.7VYesNoCheck 35 pin of U501& R511, C508Change U202RF freq.appear at 5 pinof F102YesNoVoltageat 7 pin of U201 = 3.6VNoYesCheck U601 &Ambient circuitRF freq.appear at 5 pinof F101YesNoBRF freq.appear at 25 pinof CON1NoYesCGood UHF freq.appear at 5 pin of U201?NoYesChange U201 UHF freq.appear at 6 pin of U401?No UHF freq.appear at collector of Q401?NoYesYesChange Q401 UHF freq.appear at collector of Q402?NoYesVoltageat 4 pin of U401= 3.3VYesNo CheckU602 &PeripheralCircuitChange U401Change Q402
LGC-800W LG Information & Communications, Ltd. - 26 -Voltage at3 pin of Q108 = 3.6VNoYesCheck U701BRF freq.appear at 1 pin of Q108?NoYes Change Q108RF freq.appear at 2 pin of F101?NoYesChange F101Voltage at5 pin of U601 = 3.6VNo Change U601YesNoYesVoltage at1 pin of U601 = 5VRefer to [1]DVoltage at4/8 pin of PWR1 = 5VNoYesCRF freq.appear at 3 pin of U102?NoYesChange PWR1 or PWR detect circuitNoYesChange U102RF freq.appear at 9 pin of F103?Voltage at4 pin of Q101 = 5VYesDChange Q101NoYesChange F103Change CON1RF freq.appear at 25 pin of CON1?
LGC-800W LG Information & Communications, Ltd. - 27 -8. When Rx sensitivity isn't normal.STARTSetup Test mode* PWR On* Supply to 25 pin of CON1 (only a carrier)CheckRx RF signal at 11 pinof F103BadGoodCheckRx RF signal at collectorof F104BadGoodResolering orChange F103Check F104 &Ambient circuitCheckRx RF signal at 1 pinof U104BadGoodCheck Q105 &Ambient circuitCheckRx IF signal at 6 pinof U104BadGoodVoltageat 4 pin of U104= 3.3VNoYesCheck U602 &Ambient circuitCheck U104 &Ambient circuitCheckRx IF signal at 9/10 pinof U203BadGoodCheck U203 &Ambient circuitCheckRx RF signal at 3 pinof U104BadGoodVoltage4/5/7 pin of U401= 3.3 VNoYes Check U402 &Ambient circuitCheck RxSenditivityBadChangeMain BoardOKGood
LGC-800W LG Information & Communications, Ltd. - 28 - CHAPTER 5. Test Procedure
LGC-800W LG Information & Communications, Ltd. - 29 -1. Assembly and Disassembly Diagram2. Block & Circuit Diagram3. Part List4. Component Layout5. Accessories - Desktop Charger - Travel Charger - Cigar Lighter Charger - Hands Free Kit APPENDIX

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