UMTS 移动通信系统

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1、Wireless Technology Innovation LabsWTI1Wireless TechInnovationWireless TechInnovation北京邮电大学无线通信新技术研究室北京邮电大学无线通信新技术研究室XWireless Technology Innovation LabsWTI2分类分类：频分多址 (FDMA)-按频道划分用户，频带独享，时间共享时分多址 (TDMA)-按时隙划分用户，时隙独享，频率共享码分多址 (CDMA)-按码型划分用户，时隙/频率共享Wireless Technology Innovation LabsWTI3含义含义：每个用户占用一个频

2、率用户识别用户识别：频道号特点特点：简单，容易实现，适用于模拟和数字信号以频率复用为基础，以频带划分各种小区需要严格的频率规划，是频率受限和干扰受限系统以频道区分用户地址，一个频道传输一路模拟/数字话路对功控的要求不严，硬件设备取决于频率规划和频道设置基站由多部不同载波频率的发射机同时工作不适宜大容量系统使用应用：应用：模拟/数字蜂窝移动通信系统PowerFrequencyTimeFDMAWireless Technology Innovation LabsWTI4含义含义：每个用户占用一个时隙用户识别：用户识别：时隙特点：特点：以频率复用为基础，小区内以时隙区分用户每个时隙传输一路数字信号，

3、软件对时隙动态配置系统要求严格的系统定时同步对功控的要求不严是时隙受限和干扰受限系统TDD模式下，上下型信道信息可以共享应用：应用：GSM系统FrequencyPowerTimeFDMA/TDMAWireless Technology Innovation LabsWTI5FrequencyCDMAPowerTime含义含义：每个用户使用一个码型，频率/时间共享用户识别：用户识别：码型特点：特点：每个基站只需一个射频系统每个码传输一路数字信号每个用户共享时间和频率是一个多址干扰受限系统需要严格的功率控制需要定时同步软容量、软切换，系统容量大抗衰落、抗多径能力强应用：应用：IS-95 CDMA系

4、统、cdma2000系统、WCDMA系统Wireless Technology Innovation LabsWTI6扩频原理：扩频原理：以频带换取信噪比香农理论：C=Bw log2 (1+S/N)扩频系统的优点：扩频系统的优点：v 抗干扰能力强，可抗白噪声、人为干扰、多径干扰等v 保密性好。扩频信号频谱近似白噪声，若不知PN序列生成方法就难以获取原始信息v 隐蔽性好。扩频信号近似白噪声，难以检测，宽带扩频信号功率谱密度很低，难以监听v 易于实现大容量多址通信v 易于精确定时和测距v 易于采用各种先进的分集技术，如RAKE接收、智能天线等Wireless Technology Innovati

5、on LabsWTI7Wireless Technology Innovation LabsWTI8Interference SourcesLong & ShortCodeSpreadingEncoding &InterleavingLong &Short CodeCorrelatorDecode &DeinterleavingBasebandDataBasebandDataBackground NoiseExternal InterferenceOther Cell InterferenceOther User NoiseCDMA TransmitterCDMA Receiverf fc c

6、MHz BWf fc c390 kHz BW0 0kHz BW0 01.25MHz BWf fc c1.25MHz BWf fc cf fc c-100 dB/Hzf fc cSpurious SignalsInterference SourcesLong & ShortCodeSpreadingEncoding &InterleavingLong &Short CodeCorrelatorDecode &DeinterleavingBasebandDataBasebandDataBackground NoiseExternal InterferenceOther Cell Interfere

7、nceOther User NoiseCDMA TransmitterCDMA Receiverf fc c1.25f fc c9.6 kHz BW0 09.6kHz BW0 0f fc cMHz BWf fc cf fc c-100 dB/Hzf fc cSpurious SignalsMHz BW1.25Wireless Technology Innovation LabsWTI9User #3User #2User #1SynchPagingPilot1.2288 MHzfreq0123456789324063User1User3User2Walsh CodePilotPagingSyn

8、chWireless Technology Innovation LabsWTI10TransmitterReceiverDR2R3R3矢量图DR1R2=衰落!Wireless Technology Innovation LabsWTI11Transmitting antennaReceiving antenna 1Receiving antenna 2Receiving antenna3ReceiverRA1SuppressionRA2SuppressionRA3AmplificationWireless Technology Innovation LabsWTI12Transmitting

9、 antenna1, 2, 3Receiving antennaDR2R3Receiver1, 2, 31Suppression2Suppression3AmplificationWireless Technology Innovation LabsWTI1312tt|A2|A1|A3|重叠的多径信号重叠的多径信号经过匹配滤波器压缩后的信号经过匹配滤波器压缩后的信号+A1*A2*A3*A1*S1(t)+A2*S2(t)+A3*S3(t)“Rake” receiverWireless Technology Innovation LabsWTI14Wireless Technology Innov

10、ation LabsWTI15 S -P30 ksps30 kspsPilot, PowerControl and TFCI18 kbpsTime Multiplexer60 kbpsOVSFCodeGen3840 kcps3840 kcpsI3840 kcpsQ218 ComplexScramble CodeGeneratorQI+-10 ms segmentSpreading42 kbpsQscrambleIscrambleSF=128IscrambleAdd CRC & Tail Bits268 bits244 bits1/3 RateConv. Coder804 bits688 bit

11、s344 bits688 bitsFrame SegmentTrCHMux DTCHData Bits42 kbps120 bits96 bits360 bits304 bits76 bits304 bits 20 ms Frames 40 ms Frames 10 ms Frames34.4 kbpsAdd CRC & Tail Bits1/3 RateConv. Coder7.6 kbpsSegment& Match DCCHData Bits DPCCHRateMatchingRateMatching1stInterleaver1stInterleaver DPDCHFrame Segm

12、ent CCTrCH2ndInterleaver ComplexScramblingWireless Technology Innovation LabsWTI16TImTReTcos(t)Complex-valuedchip sequencefrom summingoperations-sin(t)Splitreal &imag.partsPulse-shapingPulse-shaping G1 G2 GP GS S-SCH P-SCH (point T in IAny downlinkphysical channelexcept SCHSPCch,SF,mjSdl,nQI+jQSWire

13、less Technology Innovation LabsWTI17Wireless Technology Innovation LabsWTI18Wireless Technology Innovation LabsWTI19Add CRC & Tail Bits268 bitsPilot, Power Control, &TFCI DPCCHData Bits15 kbps3840 kcpsSF=256Data OVSF Generator3840 kcpsSF=64244 bits1/3 RateConv. Coder804 bits1stInterleaver804 bitsRat

14、eMatching490 bitsGain = - 6 dBGain ComplexScramblingI+-OVSF 2Generator1,-1 I3840 kcps225 Scramble CodeGeneratorQ3840 kcpsQ402 bitsFrame Segment60 kbpsControl OVSF GeneratorCch,256,0Cch,64,16I Scramble CodeI Scramble CodeQQ DTCHData Bits60 kbps120 bits96 bits360 bits360 bits110 bits90 bits DPDCHData

15、Bits 20 ms Frames 40 ms Frames 10 ms Frames49 kbpsAdd CRC & Tail Bits1/3 RateConv. Coder1stInterleaverRateMatching11 kbpsSegment& Match DCCHData BitsTrCHMux60 kbps CCTrCH2ndInterleaverWireless Technology Innovation LabsWTI20Ijcd,1dSdpch,nI+jQDPDCH1Qcd,3dDPDCH3cd,5dDPDCH5cd,2dDPDCH2cd,4dDPDCH4cd,6dDP

16、DCH6cccDPCCHSWireless Technology Innovation LabsWTI21Wireless Technology Innovation LabsWTI22Wireless Technology Innovation LabsWTI23Wireless Technology Innovation LabsWTI24Information Bits (Input)Code Symbols (Output)0g1g1c0cWireless Technology Innovation LabsWTI25Interleaver+DDD+64 kbpsOutput64 kb

17、psOutput64 kbpsInputDDD+64 kbpsOutputSystematic PathParity PathParity Pathv Uses the Same Coder for Both Parity Generatorsv Second Parity Generator Input is Interleavedv Yields 0.5 dB Improvement Relative to Convolution Encoder for High Speed DataWireless Technology Innovation LabsWTI26v 蜂窝系统蜂窝系统-“-

18、“小区制小区制”系统系统 - - 将所要覆盖的地区划分为若干个小区，每个小区的半径可视用户的将所要覆盖的地区划分为若干个小区，每个小区的半径可视用户的分布密分布密 度在度在1-10km1-10km左右左右, ,在每个小区设立一个基站为本小区范围内的用户在每个小区设立一个基站为本小区范围内的用户服务。服务。 - “- “频率复用频率复用”的概念的概念 - - 特点：用户容量大，服务性能较好，频谱利用率较高，用户终端小特点：用户容量大，服务性能较好，频谱利用率较高，用户终端小巧且电池使用时间长，辐射小等巧且电池使用时间长，辐射小等 - - 问题：系统复杂，越区切换，漫游，位置登记；更新和管理以及系

19、问题：系统复杂，越区切换，漫游，位置登记；更新和管理以及系统鉴权等统鉴权等v 蜂窝分类蜂窝分类 - - 宏蜂窝宏蜂窝 ( (Macro-cell) 2-20kmMacro-cell) 2-20km - - 微蜂窝微蜂窝 ( (Micro-cell) 0.4Micro-cell) 0.42 km2 km - - 微微蜂窝微微蜂窝 ( (Pico-cell) 400mPico-cell) 400m - - 分层蜂窝分层蜂窝 ( (由多种蜂窝组成由多种蜂窝组成) )Wireless Technology Innovation LabsWTI27Wireless Technology Innovati

20、on LabsWTI28Wireless Technology Innovation LabsWTI29Wireless Technology Innovation LabsWTI30Wireless Technology Innovation LabsWTI31Wireless Technology Innovation LabsWTI32Wireless Technology Innovation LabsWTI33Wireless Technology Innovation LabsWTI34FDMA 频率复用频率复用11111111113626221457CDMA 频率复用频率复用Wi

21、reless Technology Innovation LabsWTI35Radio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio tow

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23、adio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerRadio towerWireless Technology Innovation LabsWTI36Sector-1Sector-2Sector-3Sector-4Sector-5Sector-6Sect

24、or-1Sector-3Sector-2G = 3 x 0.85 = 2.55G = 6 x 0.85 = 5.1* 扇区的重叠按 15 %记Wireless Technology Innovation LabsWTI37Wireless Technology Innovation LabsWTI38W-cdmaWireless Technology Innovation LabsWTI39Wireless Technology Innovation LabsWTI40Wireless Technology Innovation LabsWTI41Wireless Technology Innovation LabsWTI42Thank you!.any questions are welcome!徐国鑫无线新技术研究室