AnyDATA DTSS-1900 CDMA Data Modem with DTSS-1900 User Manual EMII1900 service manual

AnyDATA Corporation CDMA Data Modem with DTSS-1900 EMII1900 service manual

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DTSS 1900 User Manual

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Interface Description EMII-1900 Service Manual Application Information EMII-1900 V1.0 AnyDATA.NET Proprietary  Use Subject to Restrictions CAUTION n Operating Requirements The user can not make any changes or modifications not expressly approved by the party responsible for compliance, otherwise it could void the user's authority to operate the equipment. To satisfy FCC RF exposure compliance requirements for a mobile transmitting device, this device and its antenna should generally maintain a separation distance of 20cm or more from a person…s body. Special accessories In order to ensure this device in compliance with FCC regulation, the special accessories are provided with this device and must be used with the device only. The user is not allowed to use any other accessories than the special accessories given with this device

Interface Description EMII-1900 Service Manual Application Information EMII-1900 V1.0 AnyDATA.NET Proprietary  Use Subject to Restrictions Table of Contents General Introduction ................................................................................................................................ 2 CHAPTER 1. System Introduction 1. System Introduction .................................................................................................... 3 2. Features and Advantages of CDMA Module ........................................................... 4 3. Structure and Functions of CDMA Module ............................................................. 7 4. Specification ............................................................................................................... 8 CHAPTER 2. NAM Input Method(Inputting of telephone numbers included) 1. NAM Programming Method and Telephone Number Input Method ......................... 11 CHAPTER 3. Circuit Description 1. Overview .................................................................................................................... 14 2. RF Transmit/Receive Part ........................................................................................ 14 3. Digital/Voice Processing Part ......................................................................... ®®.. 17 CHAPTER 4. FCC Notice Appendix .............................................................................................................................. 22 1. Assembly and Disassembly Diagram 2. Block & Circuit Diagram 3. Part List 4. Component Layout

EMII-1900 1. System Introduction 1.1 CDMA Abstract The cellular system has a channel hand-off function that is used for collecting the information on the locations and movements of radio mobile telephones from the cell site by automatically controlling several cell site through the setup of data transmission routes and thus, 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. 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 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 SDMA 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 method available 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 characteristics 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 correlator 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 instead, processed as noise and appears as the self-interference of the system. CHAPTER 1. System Introduction

Interface Description EMII-1900 Service Manual Application Information EMII-1900 V1.0 AnyDATA.NET Proprietary  Use Subject to Restrictions 2. Features and Advantages of CDMA Module 2.1 Various Types of Diversities 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 more wider frequency band. The fading related to normal frequency can affect the normal 200~300kHz among signal bands and accordingly, serious affect 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 and 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 control on all the mobile stations, the system capacity 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 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 reception 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 office transmit signals in the cells are received by the cell site in the same strength. Moreover, the backward closed loop power control used by the mobile station to control power with the commands issued out by the cell site. The cell site receives the signal of each corresponding mobile station and compares this with the pre-set threshold value and then, issues out power increase/decrease commands to the 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 are complemented.

Interface Description EMII-1900 Service Manual Application Information EMII-1900 V1.0 AnyDATA.NET Proprietary  Use Subject to Restrictions 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 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 support, 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.

Interface Description EMII-1900 Service Manual Application Information EMII-1900 V1.0 AnyDATA.NET Proprietary  Use Subject to Restrictions 3. Structure and Functions of CDMA Module The mobile station of CDMA system is made up of a radio frequency part and logic/control (digital) part. The mobile station antenna is connected with the transmitter/receiver via a duplexer filter so that it can carry out the transmit/receive function at the same time. The transmit frequency is the 60MHz band of 1851.25 ~ 1908.75MHz, whereas the receive frequency is the 60MHz band of 1931.25 ~ 1988.75MHz. The transmit/receive frequency is separated by 80MHz. The RF signal from the antenna is converted into intermediate frequency(IF) band by the frequency synthesizer and frequency down converter and then, passes the bandpass SAW filter having the 1.25MHz band. IF output signals that have been filtered from spurious signal are converted into digital signals via an analog-to-digital converters(ADC) and then, sent out respectively to 5 correlators in each CDMA de-modulator. Of these, one is called a searcher whereas the remaining 4 are called data receiver(finger). 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. Then, 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 out multi-paths in accordance with terrain and building reflections. On three data receivers, the most powerful four 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 during the two cell sites. Moreover, four data receivers are allocated in order to carry out the de-modulation of these paths. Data output that has been demodulated change the 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 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.

Interface Description EMII-1900 Service Manual Application Information EMII-1900 V1.0 AnyDATA.NET Proprietary  Use Subject to Restrictions 4. Specification 4.1 General Specification 4.1.1 Transmit/Receive Frequency Interval : 80 MHz 4.1.2 Number of Channels (Channel Bandwidth) CDMA : 42 CH (BW: 1.23MHz) 41.3 Operating Voltage : DC 6~12V 4.1.4 Operating Temperature : -30° ~ +60° 4.1.5 Frequency Stability CDMA : ⥮150 Hz 4.1.6 Antenna : Whip Type, 50 Ω 4.1.7 Size and Weight 1) Size : 121mm x 47mm x 24mm (L x W x D) with case 2) Weight : 112g 4.1.8 Channel Spacing CDMA : 1.25MHz 4.2 Receive Specification 4.2.1 Frequency Range Digital : 1931.25 MHz ~ 1988.75 MHz 4.2.2 Local Oscillating Frequency Range : 1749.62MHz 30MHz 4.2.3 Intermediate Frequency : 210.38MHz 4.2.4 Sensitivity less than -104dBm 4.2.5 CDMA Input Signal Range • Dynamic range : -104~ -25 dBm (more than 80dB) at the 1.23MHz band.

$Interface Description EMII-1900 Service Manual Application Information EMII-1900 V1.0 AnyDATA.NET Proprietary  Use Subject to Restrictions 6) As shown in the picture above, service file input plane will be displayed (See if clock is running. If it isn…t, communication with PC is not activated. Repeat step 1 through 5, or reset the power of modem and repeat step 1 through 5) 7) Type NAM Programming script like the example shown below, <NAM Programming script example> Mode offline-d [ENTER] nv_write name_nam {0," AnyDATA telecom "} [ENTER] nv_write name_nam {1," AnyDATA telecom "} [ENTER] Mode reset [ENTER] SCRIPTINPUT WINDOW$

$Interface Description EMII-1900 Service Manual Application Information EMII-1900 V1.0 AnyDATA.NET Proprietary  Use Subject to Restrictions 1. Overview RFT3100 receives modulated digital signals from the MSM of the digital circuit and then, changes them into analog signals by the digital/analog converter (DAC, D/A Converter) in order to create baseband signals. Created baseband signals are changed into IF signals by RFT3100 and then, fed into the Mixer after going through AGC. IF signals that have been fed are mixed with the signals of VCO and changed into the RF signals and then, they are amplified at the Power AMP. Finally, they are sent out to the cell site via the antenna after going through the isolator and duplexer. 2. RF Transmit / Receive Part 2.1 CDMA Transmit End 8 bit I and Q transmit signals are inputted into 2 DACs (DIGITAL-TO-ANALOG CONVERTER) from the output terminal I_DATA, I_DATA\, Q_DATA, Q_DATA\ of MSM through the input terminals I_DATA, I_DATA\, Q_DATA, Q_DATA\ of RFT3100. Transmit signal input speed is two times of TXCLK+, TXCLK- which are two transmit/receive reference frequency. Among transmit signals being inputted, signals are inputted into I signal DAC when the transmit clock is in the rise edge, whereas signals are inputted into Q Signal DAC during the drop edge. I and Q transmit signals are compensated and outputted at MSM in order to compensate the 1/2 clock time difference generated between reference clocks. In the signals coming out from the output terminal of DAC, there are spurious frequency ingredients resulting from DAC output transition edge and parasite ingredients, transmit clock frequencies and harmonics which are unwanted signals. Accordingly, spurious ingredients are removed by passing the signals through LPF of passband 6.30KHz. Unlike the receive end, the transmit end LPF requires no OFFSET adjustment. Analog baseband signals that have passed the CDMA LPF are mixed with I and Q signals of frequency 130.38 MHz (260.76 MHz created in the RFT3100 internal VCO are divided by half into frequency 130.38MHz having the phase difference of 90 degrees) in two mixers. The mixed signals are added again and converted into IF frequency 130.38 MHz ⥮630 KHz (CDMA Spread Power Density Modulated Signals) and then, outputted. 2.2. Tx IF/Baseband Processors, RFT3100 (U102) The RFT3100 includes digital-to-analog converters(DAC) for converting digital baseband to analog baseband, low-pass filters, a mixer for up-converting to IF and an 85 dB dynamic range Tx AGC amplifier. The RFT3100 has an IF mixer for upconverting analog baseband to IF, a programmable PLL for generating Tx IF frequency, single sideband upconversion from IF to RF, two cellular and two PCS driver amplifiers. The RFT3100 will operate over the follow Tx frequency ranges : Cellular band 824MHz ~ 925MHz PCS band 1750MHz ~1910MHz CHAPTER 3. Circuit Description$