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CDMA System Basis. Features of Wireless Telecomm. Individually Bad propagation environment Co-channel, Adjacent channel interference and near-far effect. Contradiction between limited frequency resource and vast numbers of subscribers. Complicated network and control equipment are required. - PowerPoint PPT Presentation
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ZTE 中兴 CDMA
CDMA System BasisCDMA System Basis
ZTE 中兴 CDMA
Features of Wireless Features of Wireless TelecommTelecomm
IndividuallyIndividually Bad propagation environmentBad propagation environment Co-channel, Adjacent channel Co-channel, Adjacent channel
interference and near-far effect.interference and near-far effect. Contradiction between limited Contradiction between limited
frequency resource and vast frequency resource and vast numbers of subscribers.numbers of subscribers.
Complicated network and control Complicated network and control equipment are required.equipment are required.
ZTE 中兴 CDMA
Classification of Wireless Classification of Wireless TelecommTelecomm
ClassificationMode
Class
RF Operation Simplex, half-duplex, duplex
Signal Analog, Digital
Modulation FM, PM, AM
Multiple Access
FDMA, TDMA, CDMA
ZTE 中兴 CDMA
ZTE 中兴 CDMA
Frequency Reuse
ZTE 中兴 CDMA
Evolution of Wireless Evolution of Wireless TelecommTelecomm
1G 2G 33GG
AAnnaalloogg DDiiggiittaall DDiiggiittaall
VVooiiccee VVooiiccee && DDaattaa VVooiiccee && hhiigghh--ssppeeeedd
DDaattaa AAMMPPSS CCDDMMAA CCDDMMAA22000000
TTAACCSS GGSSMM//TTDDMMAA GGPPRRSS WW__CCDDMMAA
11998800’’ss 11999922 11999999 22000011 22000033
ZTE 中兴 CDMA
Makeup of Wireless Makeup of Wireless TelecommTelecomm
MS
MS
MSBTS BTS
BTSBSC
MSC
BTSBTS
BTS
BSC
UmAbis A
BSS
PSTN
HLR
VLR
MSC
ISDN
MS
MS: Mobile StationBSS: Base Station SystemBTS: Base-station Transceiver SystemBSC: Base_Station ControllerMSC:Mobile-service Switching CenterVLR:Visiting LocationRegisterHLR:Home Location RegisterPSTN:ISDN:
ZTE 中兴 CDMA
Spectrum Spreading Spectrum Spreading TechniqueTechnique
Theoretical Basis is Shanon equationTheoretical Basis is Shanon equationC=B*logC=B*log22(1+S/N)(1+S/N)
DSSS applied in CDMADSSS applied in CDMA Used in military communication in Used in military communication in
1950’s and 1960’s1950’s and 1960’s Qualcomm company successfully put Qualcomm company successfully put
it into commercially cellular wireless it into commercially cellular wireless telecommunication by the end of telecommunication by the end of 1980’s1980’s
ZTE 中兴 CDMA
Signal processing by DSSSSignal processing by DSSS
ZTE 中兴 CDMA
Features of CDMA SystemFeatures of CDMA System（（ 11 ）） Large capacityLarge capacity
8~10 8~10 times of analog systemtimes of analog system High-quality serviceHigh-quality service
88Kb/s QCELP EQUALS 13Kb/s of Kb/s QCELP EQUALS 13Kb/s of GSM;GSM;
13Kb/s QCELP EQUALS 64kb/s of 13Kb/s QCELP EQUALS 64kb/s of wirelinewireline
SSoft handoff lowers call drop rateoft handoff lowers call drop rate RAKE receiving overcomes multi-path RAKE receiving overcomes multi-path
fadingfading Good secrecyGood secrecy
ZTE 中兴 CDMA
Features of CDMA SystemFeatures of CDMA System （（ 22 ）） Soft capacitySoft capacity MS’s averaging transmission power MS’s averaging transmission power
is lowered, decreasing radiation to is lowered, decreasing radiation to human body and environment . Be human body and environment . Be named as “Green Handset”named as “Green Handset”
Easy to realize dual-mode operationEasy to realize dual-mode operation System complexity increasedSystem complexity increased
ZTE 中兴 CDMA
Key techniques of CDMA Key techniques of CDMA （（ 11 ）） Diversity receiving Diversity receiving
Time diversityTime diversity————interleaving, error-interleaving, error-detection and correctiondetection and correctionFrequency diversityFrequency diversity————inherent feature inherent feature of wideband communication of wideband communication Space diversitySpace diversity————multiple antenna multiple antenna receiving, RAKE receiving, soft handoffreceiving, RAKE receiving, soft handoff
ZTE 中兴 CDMA
Key techniques of CDMA Key techniques of CDMA （（ 22 ）） Precise power controlPrecise power control
Open loop power control on reverse Open loop power control on reverse linklink
Closed loop power control on Closed loop power control on reverse linkreverse link
Outer loop power control on reverse Outer loop power control on reverse linklink
Power control on forward linkPower control on forward link
ZTE 中兴 CDMA
Key techniques of CDMA Key techniques of CDMA （（ 33 ）） Rate variable codec (QCELP)Rate variable codec (QCELP) VOICE Detection (VOD)VOICE Detection (VOD) SynchronizationSynchronization Mobile assisted soft handoffMobile assisted soft handoff
ZTE 中兴 CDMA
Key techniques of CDMA Key techniques of CDMA （（ 44 ）） Blossoming & WiltingBlossoming & Wilting Low ELow Ebb/N/Noo and high redundant error and high redundant error
correction encodingcorrection encoding Multiple accessMultiple access ：： long PN code, long PN code,
short PN code and WALSH short PN code and WALSH orthogonal codeorthogonal code
ZTE 中兴 CDMA
Channel structureChannel structure
Forward ChannelsForward Channels
Piloting channelPiloting channelSynchronizing channelSynchronizing channel
Paging channelPaging channel
Traffic channelTraffic channel
Reverse ChannelsReverse Channels
Access channelAccess channelTraffic channelTraffic channel
ZTE 中兴 CDMA
Forward Traffic
Traffic ChannelForward
Channel
Paging
Forward TrafficChannel
CDMA Cell Site
Sync
Pilot
Walsh Code Assignment0 -> Pilot32 -> Sync1-7 -> Paging(s)rem. -> Fwd. Traffic
ZTE 中兴 CDMA
IS-95A Channel Modulation--Forward IS-95A Channel Modulation--Forward LinkLink
Convolutional Encoder
r = 1/2, K = 9
PagingChannel
Bits
Code Symbol
SymbolRepetition
ModulationSymbol
WalshFunction p
DecimatorLong CodeGenerator
Long CodeMask forPaging
Channel p
9.6 kbps 4.8 kbps 2.4 kbps 1.2 kbps
Convolutional Encoder
r = 1/2, K = 9
Forward TrafficChannel code
channelInformation
Bits for User mwith Rate Set 1(172, 80, 40, or16 bits/frame)
Code Symbol
Block Interleaver
Add 8-bitEncoder Tail per Frame
Add FrameQuality Indica-tors (12, 8, 0, or
0 bits/frame)8.6 kbps 4.0 kbps 2.0 kbps 0.8 kbps
SymbolRepetition
ModulationSymbol
ModulationSymbol
19.2 ksps
PowerControl
Bits
800 bps
MUX *
800 Hz
9.6 kbps 4.8 kbps
SyncChannel
Bits
Pilot Channel (All 0’s)
WalshFunction 0
19.2 ksps
Block Interleaver
ModulationSymbol
19.2 ksps 9.6 ksps 4.8 ksps 2.4 ksps
19.2 ksps19.2 ksps 9.6 ksps
19.2 ksps
Convolutional Encoder
r = 1/2, K = 9
Code Symbol
SymbolRepetition
ModulationSymbol
WalshFunction 32
1.2 kbpsBlock
Interleaver
ModulationSymbol
4.8 ksps2.4 ksps 4.8 ksps
19.2 ksps
1.2288 Mcps
DecimatorLong CodeGenerator
Long CodeMask forUser m
19.2 ksps
1.2288 McpsDecimator
WalshFunction n
A
A
A
A
* Power control bits are not multiplexed in for suppemental code channels ofthe Forward Traffic Channels
ZTE 中兴 CDMA
Procedure of MS’s Procedure of MS’s COMMUNICATIONCOMMUNICATION
Searching base station’s pilot Searching base station’s pilot channelchannel
Demodulating synchronizing Demodulating synchronizing channelchannel
MS requests on access channelMS requests on access channel BS responds on paging channelBS responds on paging channel Traffic channel is assigned for Traffic channel is assigned for
communicationcommunication
ZTE 中兴 CDMA
Power On
MSInitialStatus
MS idle status
System accessstatus
MS in trafficChannel
status
MS fully catchesSystem timing
MS paged, originating or
registering
MS idle changeover when
NGHBR_CONFIG is”011”
Access channel confirmation
End traffic channel
Indication of traffic channel
Task Initialization Start analog mode
End analog mode
Notes ： not all are listed out
ZTE 中兴 CDMA
ZXC10-BSS System ZXC10-BSS System structure-BSCstructure-BSC
BSC: Base_Station ControllerBSC: Base_Station Controller
BTS: Base-station Transceiver BTS: Base-station Transceiver SystemSystem
NCM: Network Control ModuleNCM: Network Control Module
HIRS: High-speed HIRS: High-speed Interconnect Router Interconnect Router SubsystemSubsystem
CDSU: Channel/Digital Service CDSU: Channel/Digital Service UnitUnit
TCM: Timing Control ModuleTCM: Timing Control Module
SVM: Selector Vocoder ModuleSVM: Selector Vocoder Module
SVICM: Selector Vocoder SVICM: Selector Vocoder Interface Control ModuleInterface Control Module
CPM: Call Process ModuleCPM: Call Process Module
OMC: Operation & OMC: Operation & Maintenance CenterMaintenance Center
SVMSVM
SVM
BTSBTSBTS
LAN
TO OMC
SVICM
H I R S
CDSU
Abi s Abi s
Gps orGlonass
MSC
CPMBSC
SVMSVM
SVM
NCM
TCM
SVICM
ZTE 中兴 CDMA
ZXC10-BSS System ZXC10-BSS System structure-BTSstructure-BTS
BSC
Gps orGlonass
TCM RFIM
TRx HPA RFE
BTMCCM
CDSU
Ot her BTS
HIRS
CHM
CHMCHM
ATM or E1
BTS
BTS: Base-station Transceiver SystemBTS: Base-station Transceiver System
CHM: Channel Processing ModuleCHM: Channel Processing Module
CCM: Communication Control ModuleCCM: Communication Control Module
HIRS: High-speed Interconnect Router HIRS: High-speed Interconnect Router SubsystemSubsystem
TCM: Timing Control ModuleTCM: Timing Control Module
RFIM: RF Interface ModuleRFIM: RF Interface Module
TRx: TransceiverTRx: Transceiver
HPA: High Power AmplifierHPA: High Power Amplifier
RFE: RF Front EndRFE: RF Front End
CDSU: Channel/Digital Service UnitCDSU: Channel/Digital Service Unit
BTM: Base-station Test ModuleBTM: Base-station Test Module
BSC: Base-station ControllerBSC: Base-station Controller
ZTE 中兴 CDMA
ZXC10_BSS System ZXC10_BSS System Specification-BSCSpecification-BSC
Maximal BTS supported: Maximal BTS supported: 512512 VocoderVocoder ：： 72007200 Maximal Channels (including payoff and soft handoff):Maximal Channels (including payoff and soft handoff):512 512 X X
32 = 1638432 = 16384 Maximal traffic channels: Maximal traffic channels: 512 512 X 20 = 10240X 20 = 10240 Maximal subscribers: Maximal subscribers: 102,500*102,500* BTS side trafficBTS side traffic ：： 2,930 2,930 Erl*Erl* BHCABHCA ：： 125,000*125,000* TrafficTraffic ：： 1.281.28BHCA/subscriberBHCA/subscriber
ZTE 中兴 CDMA
ZXC-10 BSS-transition ZXC-10 BSS-transition to to 33GG
Capacity Capacity increasedincreased
Non-symmetrical Non-symmetrical data service data service providedprovided
For:For:6464Kb/sKb/s Rev:Rev:14.414.4Kb/sKb/s
Backward Backward compatible with compatible with 9595AA
IS95 A IS95 B CDMA2000 1X CDMA2000 3X
Capacity doubled (relative to 95A)
Data service 144Kb/s 307.2Kb/s(max)
Backward compatible with 95A/B
Data service 384Kb/s 2Mb/s(max)
Backward compatible with 95A/B/1X
Features:
