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Published byLeslie Floyd Modified over 9 years ago
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Welcome to ZTE University! 2004.10.3
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Class Rules Class Hours: 8:40 AM - 11:50 AM 14:10PM-17:20 PM Little Breaks: Several short breaks throughout class Turn down ringers on mobile phones. No smoking in classroom
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BSS Course Agenda Course 1: CDMA Foundation Theory Course 2: BSS Hardware Intruduction and Operation Course 3: Practice in Lab
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Course 1 CDMA Foundation Theory CDMA Overview CDMA Basic Principle CDMA Channel Structure and Modulation CDMA Key Technology
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CDMA Overview 2004.10.3
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Objectives Upon completion of this lesson, the student will be able to master: -- the history of mobile communication -- the advantage of CDMA -- CDMA migration from 2G to 3G -- CDMA spectrum usage -- the role of ZTE in CDMA
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Mobility : –flexible and convenient , global personal communication Poor environment and conditions : –Co-channel interference, multi-path(space and time)shadow effect and delay, power change and other noise Multiple MS and channels : –Interference 、 near and far effect Limit of frequency resources Reliability is important –registration, handoff, switching Characteristics of Mobile Communication
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Evolution of Mobile Communications System AMPS: Advanced Mobile Phone System TACS: Total Access Communication System GPRS: General Packet Radio Services
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2Mbps 153.6kbps CDMA 1xRTT CDMA 1xEV-DV CDMA IS-95 CDMA 1xEV-DO CDMA 3x 5x CDMA Evolution Paths 2G2.5G3G 9.6kbps
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CDMA-Its History & Status 1993, the first CDMA standard IS-95 was issued by Qualcomm(U.S.A); In 1995, CDMA technologie was put into commercialization in Hongkong and America on large scale; In 1997, CDMA trial networks were constructed in Beijing, Xi’an, Shanghai and Guangzhou in China; In April, 2001, China Unicom began to construct CDMA networks— the largest in the world; At present, CDMA commercial networks are established in about 40 countries or area, almost 20% of all users in the world.
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Frequency reuse facto is 1; network design and expanding become much easier Frequency reuse facto is 1; network design and expanding become much easier Advantages of CDMA AMPS, D-AMPS, N-AMPS CDMA 30 10 kHz 200 kHz 1250 kHz 131 Users 8 Users 20 Users 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 3 4 4 3 2 5 6 1 7 Typical Frequency Reuse N=7 Typical Frequency Reuse N=4 Typical Frequency Reuse N=1 Vulnerability: C/I 17 dB Vulnerability: C/I 12-14 dB Vulnerability: E b /N o 6--7 dB GSM
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large coverage almost 2 times than GSM, save money for operator large coverage almost 2 times than GSM, save money for operator Example:cover 1000 km 2 : GSM need 200 BTS , CDMA only need 50 BTS Attention: exact result need “Link Budget ” Example:cover 1000 km 2 : GSM need 200 BTS , CDMA only need 50 BTS Attention: exact result need “Link Budget ” Advantages of CDMA
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High spectrum capacity , 8--10 times than AMPS,4—6 times than GSM Frequency Time Power Frequency Time Power Frequency Time Power FDMA TDMA CDMA FDMA---Different user use different frequncy TACS 、 AMPS TDMA---Different user use different time slot of one frequency GSM 、 DAMPS CDMA---Different user use same frequency at the same time,but with different spreading code Advantages of CDMA
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High privacy,hard to wiretapping Spread code Information signal TX Demodulated signal RX Spread code Spread signal Each user is below the noise deeply Advantages of CDMA
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CDMA : ”make before break”---soft handoff Other systems: “make after break”---hard handoff CDMA : ”make before break”---soft handoff Other systems: “make after break”---hard handoff Use soft handoff, decrease drop-call rate Advantages of CDMA
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Good voice quality, use 8k,13K(QCELP,EVRC)voice coding—the best coding method in the world. Voice quality (MOS) 64k PCM 13k GSM 8k CDMA 13k CDM A 8kEVR C CDMA Advantages of CDMA
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Perfect Power Control and voice activation make the MS Power low, healthy for humanbody—green mobile phone. Perfect Power Control and voice activation make the MS Power low, healthy for humanbody—green mobile phone. Advantages of CDMA Mean Power Max Power GSM: 125mW 2W CDMA: 2mW 200mW Mean Power Max Power GSM: 125mW 2W CDMA: 2mW 200mW
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95A 95B Software update Replace MS to get new service 95B 1X Add 1X channel board Software update Replace MS to ge new service 1X 1XEV Add 1XEV channel board Software update Replace MS to get new service inexpesive Technical Scheme : Smooth migration to 3G and the operator’s benefit is protected at the most Smooth migration to 3G and the operator’s benefit is protected at the most Almost free inexpensive Economic Scheme : Advantages of CDMA
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CDMA 800 MHz Cellular Spectrum Usage All CDMA RF carriers are 1.25 MHz. wide –Can serve ~20 users /8 kb vocoder Possible CDMA Center Freq. Assignments Channel Numbers Forward link (i.e., cell site transmits) Reverse link (i.e., mobile transmits) 824 MHz 849 MHz 869 MHz 894 MHz other uses A” ABA’B’ 110 1.52.5 ABA’B’ 110 1.52.5 991 1023 1 333334666667716717799991 1023 1 333334666667716717799 ~300 kHz. “guard bands” possibly required if adjacent- frequency signals are non-CDMA (AMPS, TDMA, ESMR, etc.)
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CDMA PCS 1900 MHz Spectrum Usage
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CDMA Frequency Channel Assignment at 800 MHz Cellular IS-95 Recommends to Start CDMA Deployment with Either the Primary or the Secondary Channel 1 334667991 1023 333 666715799716 Channel Numbers A BandB BandA’A”B’ 10193778119160201242283384425466507548589630691777 CDMA A-Band CarriersCDMA B-Band Carriers 876543211234567998 **** * Requires frequency coordination with non-cellular interferers ** Requires frequency coordination with A- band carrier A Band Primary Channel283 A Band Secondary Channel691 B Band Primary Channel384 B Band Secondary Channel777 736
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ZTE’s Activities in CDMA In 1995, CDMA mobile telecommunication project was started In November, 1999, ZTE signed the “Agreement on CDMA R&D” with Qualcomm In August, 2000, the first field trial was set up. In September, 2000 , ZTE presented the first CDMA handset with UIM in the world. In January, 2001, the first cdma2000-1x call was passed through in lab In March, 2001, ZTE cdma2000-1x realized the integrated transmission of voice, data & image.The data rate reach up to 153.6Kbps. The certificates acquired: –CDMA 800M ZXC10-MSC/VLR, HLR/AUC,BSC, BTS network access licenses –CDMA 800M/1.9G ZXC10-BTS type approval certificates
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ZTE A Famous CDMA Brand 2G/3G 终端 Abis PSTN/PLMN BSC/ PCF (1X) Internet 路由器 IP BTS ( IS-95 ) BSC ( IS-95 ) Abis E1 Um IS95 Um IS2000 E1 STM-1 E1 STM-1 Ethernet MSC/VLRHLR/AUC PDSN/FA AAA HA OMC SC WIN BTS ( IS-95 ) BSC/ PCF (1X) BTS ( 1X ) E1 业务服务器 Ethernet
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The End!
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