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ORA000003 CDMA2000 Principle
ISSUE4.0
ORA000003 CDMA2000 Principle
ISSUE4.0
HUAWEI, Mobile Network Curriculum Development Section
ObjectivesObjectives
After this presentation, you will be familiar with:
the development of mobile communication system
the structure of CDMA2000 network
the number planning in CDMA2000 network
the techniques used by CDMA system including:
source coding, channel coding, interleaving, scrambling,
spreading and modulation etc.
power control, soft handoff, RAKE receiverF-PCH,F-PICH,F-SYNCH,F-FCH,F-SCH,R-ACH,R-PICH
Long code, short code and Walsh code
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Transmission TechniquesTransmission Techniques
Traffic channels: differentusers are assigned uniquecode and transmitted overthe same frequency band,for example, WCDMA andCDMA2000
Traffic channels: different frequency bandsare allocated to different users,for example,AMPS and TACS
Traffic channels: different time slotsare allocated to different users, forexample, DAMPS and GSM
Frequ
ency
Time
Power
Frequ
ency
Time
Power
Frequ
ency
Time
Power
FDMA
TDMA
CDMA
User
User
User
UserUser
User
Introduction
3G Objectives3G Objectives
3G is developed to achieve:
Universal frequency band for standard and seamless
global coverage
High spectral efficiency
High quality of service with complete security and
reliability
Easy and smoothly transition from 2G to 3G, compatible
with 2G
Provide multimedia services, with the rates:
Vehicle environment: 144kbps
Walking environment: 384kbps
Indoor environment: 2Mbps
Introduction
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Standards for 3GStandards for 3G
3G system
CDMA2000
3GPP2
FDD mode
WCDMA
3GPP
FDD mode
TD-SCDMA
CWTS
TDD mode
Introduction
A Comparison b/w 3G standardsA Comparison b/w 3G standards
WCDMA CDMA2000 TD-SCDMA
Receiver type RAKE RAKE RAKE
Close loop powercontrol Supported Supported Supported
Handoff Soft/hard handoff
Demodulationmode
Coherent
Chip rate (Mcps) 3.84 N*1.2288 1.28
Transmissiondiversity mode
TSTD, STTDFBTD
OTD, STS No
Synchronizationmode
Asynchronous Synchronous Asynchronous
Core network GSM MAP ANSI-41 GSM MAP
CoherentCoherent
Soft/hard handoffSoft/hard handoff
Introduction
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IS95A9.6kbps
IS95B115.2kbps
CDMA2000 307.2kbps
Heavier voiceservice capacity ;
Longer period ofstandby time
CDMA20003X
CDMA20001X EV
1X EV-DO
1X EV-DV
1995 1998
2000
2003
Development of CDMADevelopment of CDMA
Higher spectrum efficiency and network capacity
Higher packet data rate and more diversified services
Smooth transit to 3G
Introduction
Frequency Allocation In CDMA2000Frequency Allocation In CDMA2000
Band Class 0 and Spreading Rate 1
Introduction
892.170-893.310847.170-848.310739-777ValidB(2.5MHz)
890.670-890.820845.670-845.820689-694ValidA(1.5MHz)
880.680-889.320835.680-844.320356-644ValidB(10MHz)
870.030-879.330825.030-834.3301-311ValidA(10MHz)
Base StationMobile StationCDMA
Channel
Number
CDMA
Channel
Validity
Block
Designator
Transmit Frequency Band (MHz)
The transmit frequence point for Base Station is computed by:
F=870+N*0.03
N: CDMA Channel Number
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Frequency Allocation In CDMA2000Frequency Allocation In CDMA2000
Band Class 1 and Spreading Rate 1
Introduction
1971.250-1973.7501891.250-1893.750825-875ValidF(5MHz)
1966.250-1968.7501886.250-1888.750725-775ValidE(5MHz)
1976.250-1988.7501896.250-1908.750925-1175ValidC(15MHz)
1951.250-1963.7501871.250-1883.750425-675ValidB(15MHz)
1946.250-1948.7501866.250-1868.750325-375ValidD(5MHz)
1931.250-1943.7501851.250-1863.75025-275ValidA(15MHz)
Base StationMobile StationCDMA
Channel
Number
CDMA
Channel
Validity
Block
Designator
Transmit Frequency Band (MHz)
The transmit frequence point for Base Station is computed by:
F=1930+N*0.05
N: CDMA Channel Number
CDMA2000 1X Network StructureCDMA2000 1X Network Structure
MS: Mobile Station BTS: Base Transceiver StationBSC: Base Station Controller MSC: Mobile Switching CenterHLR :Home Location Register VLR: Visitor Location RegisterPCF: Packet data Control Function PDSN: Packet Data Service NodeHA: Home Agent FA: Foreign AgentSCP: Service Control Point Radius: Remote Authentication Dial-in User Service
Abis
A1(Signaling)
A2(Traffic)
A11(Signaling)
A10(Traffic)
A3(Signaling & Traffic)
A7(Singaling)
Introduction
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Course ContentsCourse Contents
Chapter 1 Introduction
Chapter 2 CDMA Techniques & Technologies
Chapter 3 CDMA Air Interface
Chapter 4 CDMA Number planning
CorrelationCorrelation
(a)
(b)
Correlation 100% so thefunctions are parallel
Correlation 0% so thefunctions are orthogonal
CDMA Techniques & Technologies+1
-1
+1
-1
+1
-1
+1
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Orthogonal FunctionOrthogonal Function
Orthogonal functions have zero correlation. Two binary
sequences are orthogonal if their XOR output contains equal
number of 1s and 0s
0000
01010101
EXAMPLE:
CDMA Techniques & Technologies
1010
01011111
Information spreading over orthogonal codesInformation spreading over orthogonal codes
CDMA Techniques & Technologies
1 0 0 1 1
0110 0110 0110 0110 0110
1001 0110 0110 1001 1001
User Input
OrthogonalSequence
Tx Data
+1
-1
+1
-1
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Information recoveryInformation recovery
CDMA Techniques & Technologies
1 0 0 1 1+1
-1
Rx Data 1001 0110 0110 1001 10010110 0110 0110 0110 01101111 0000 0000 1111 1111
Correct Function
? ? ? ? ?
Rx Data 1001 0110 0110 1001 10010101 0101 0101 0101 0101
1100 0011 00111100 1100
Incorrect Function
Spreading and De-spreadingSpreading and De-spreading
information pulse interference White noise
The improvement of time-domain information rate means that the bandwidth of spectrum-domain
information is spread.
S(f) is the energy density.
f
Sf
The spectrum before spreading
information
f0
The spectrum before despreading
information
Interference/noise
Sf
f0 f f0
The spectrum after despreading
information
Interference/noise
Sf
f
The spectrum after spreading
information
f0
Sf
f
CDMA Techniques & Technologies
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Signal flowSignal flow
InterleavingSourcecoding
Convolution&
Interleaving
Scrambling Spreading Modulation
RFtransmission
Sourcedecoding
deinterleavingDecovolution
&Deinterleaving
Unscrambling De-spreading DemodulationRF receiving
CDMA Techniques & Technologies
Common Technical TermsCommon Technical Terms
Bit, Symbol, Chip:
A bit is the input data which contain information
A symbol is the output of the convolution, encoder, and the
block interleaving
A chip is the output of spreading
Processing Gain:
Processing gain is the ratio of chip rate to the bit rate.
The processing gain in IS-95 system is 128, about 21dB.
Forward direction: Information path from base station to
mobile station
Reverse direction: Information path from mobile station to
base station
CDMA Techniques & Technologies
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Source CodingSource Coding
Vocoder:8K QCELP
13K QCELP
EVRC
Characteristics
Support voice activity
CDMA Techniques & Technologies
Channel CodingChannel Coding
Convolution code or TURBO code is used in channel encoding
Constraint length=shift register number+1.
Encoding efficiency= (total input bits / total output symbols)
convolution encoder
Input (bits) Output (symbols)
CDMA Techniques & Technologies
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Turbo CodeTurbo Code
Turbo code is used during the transmission of large data packet.
Characteristics of the Turbo code:
The input information is encoded twice and the two output codes can
exchange information with each other during decoding.
The symbol is protected not only by the neighborhood check bits,
but also by the separate Check Bits.
The performance of a Turbo code is superior to that of a convolution
code.
CDMA Techniques & Technologies
InterleavingInterleaving
The direction of the data stream
1 2 873 64 5
1 2 873 64 5
1 2 873 64 5
1 2 873 64 5
1 2 873 64 5
1 2 873 64 5
1 2 873 64 51 2 873 64 51 2 873 64 5
1 2 873 64 5
1 1 111 11 1
2 2222
7 7 777 77 7
6 6 666 66 6
3 3 333 33 3
4 4 444 44 4
1 2 873 64 51 2 873 64 55 5 555 55 5
8 8 888 88 8
interleaving
CDMA Techniques & Technologies
2 2 2
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Out
0 0 1
1 1 0
Scrambling (M) sequenceScrambling (M) sequence
Two points are important here:
Maximum number of shift register (N)
Mask
The period of out put sequence is 2N-1 bits
Only sequence offset is change when the mask is changed
PN stands for Pseudorandom Noise sequence
CDMA Techniques & Technologies
Long CodeLong Code
The long code is a PN sequence with period of 242-1chips
The functions of a long code:
Scramble the forward CDMA channel
Control the insertion of power control bit
Spread the information on the reverse CDMA channel to identify
the mobile stations
CDMA Techniques & Technologies
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PNa
PNc
PNb
Short CodeShort Code
CDMA Techniques & Technologies
Short code is a PN sequence with period of 215 chips Sequence with different time offset is used to distinguish
different sectors
Minimum PN sequence offset used is 64 chips, that is, 512 PN
offsets are available to identify the CDMA sectors (215/64=512).
Walsh CodeWalsh Code
W2n=Wn Wn
Wn Wn
W1=0
W2=0 0
0 1
W4 =
0 00 1
0 00 1
0 00 1
Walsh code
64-order Walsh function is used as a spreading function and
each Walsh code is orthogonal to other.
Walsh Code is one kind of orthogonal code.
A Walsh can be presented by Wim where ith (row) is the
position and m is the order. For example, W24 means 0101
code in W4 matrix
CDMA Techniques & Technologies
1 1
1 0
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In forward direction, each symbol is spread with Walsh code
Walsh code is used to distinguish the user in forward link
For IS95A/B, in the reverse, every 6 symbols correspond to one
Walsh code. For example, if the symbol input is 110011,the
output after spreading is W5164 (110011=51).
For CDMA2000, in the reverse, Walsh function is used to define
the type of channel (RC 3-9)
Walsh CodeWalsh Code
CDMA Techniques & Technologies
Variable Walsh codesVariable Walsh codes
64
48
16
32
12
96 00 1 920 0 38 400 76 800 1 536 00 307200 614400
Data rate -bps-
W01=0
W02=00
W12=01
W04=0000
W24=0011
W14=0101
W34=0110
W08=00000000
W48=00001111
W28=00110011
W68=00111100
W18=01010101
W58=01011010
W38=01100110
W78 =01101001
( W016,W
816)
( W416,W12
16)
( W216,W14
16)
( W616,W14
16)
( W116,W
916)
( W516,W
1316)
( W316,W11
16)
( W716,W15
16)
The different Walsh codescorresponding to different data rates
CDMA Techniques & Technologies
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Modulation-QPSKModulation-QPSK
I
Q
I channel PN sequence1.2288Mcps
Q channel PN sequence
1.2288Mcps
Baseband filter
Baseband filter
Cos(2pfct)
Sin(2pfct)
I(t)
Q(t)
s(t)A
1.2288Mcps: the PN chip rate of the system.
After being spread, all the forward channels in the same carrier are
modulated by means of QPSK(OQPSK in the reverse), converted
into simulation signals and transmitted after clustering.
CDMA Techniques & Technologies
Power Control
Handoff
Diversity and RAKE
CDMA Techniques & Technologies
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Power ControlPower Control
Reverse power control
Open loop power control
Closed loop power control
Inner loop power control: 800 Hz
Outer loop power control
Forward power control
Message transmission mode:
threshold transmission
periodic transmission
CDMA Techniques & Technologies
Reverse Open Loop Power ControlReverse Open Loop Power Control
The transmission power required by the mobile station is determined by
the following factors:
Distance from the base station
Load of the cell
Circumstance of the code channels
The transmission power of the mobile station is relative to its received
power.
BTSMobile
Reverse Open LoopPower Control
BTS
BTS
TransmittingPower
CDMA Techniques & Technologies
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Reverse Closed Loop Power ControlReverse Closed Loop Power Control
BTS
Power Control Bit
Eb/Nt Value FER Value
Inner Loop Power Control
Outer Loop Power Control
Change in Eb/Nt Value
CDMA Techniques & Technologies
BSC
BTS
Forward Power ControlForward Power Control
MS measures the frame quality and informs the base station
to the result i.e. whether it is in the threshold or periodical
mode. Base station determines whether to change the
forward transmitting power or not.
In IS-95 system, the forward power control is slow but in
CDMA2000 system it is fast.
CDMA Techniques & Technologies
Message Transmission Mode
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HandoffHandoff
Soft handoffIt is a process of establishing a link with a target sector beforebreaking the link with the serving sector
Softer handoffLike the soft handoff, but the handoff is occurred betweenmulti-sectors in the same base station
Hard handoffHard handoff occurs when the two sectors are notsynchronized or are not on the same frequency. Interruption in
voice or data communication occurs but this interruption doesnot effect the user communication
CDMA Techniques & Technologies
Soft/Softer HandoffSoft/Softer Handoff
Multi-path combination in the BSC during soft handoff
Multi-path combination in the BTS during softer handoffs
Combine all the
power from eachsector
Power received froma single sector
CDMA Techniques & Technologies
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Pilot SetPilot Set
ActiveSet
CandidateSet
NeighborSet
RemainingSet
The pilot set, corresponding to the basestation being connected
The pilot set, not in the active set butpotential to be demodulated
The pilot set, not included in the active set orthe candidate set but being possible to beadded in the candidate set
Other pilot sets
the set of the pilots having same frequency but different PN sequence offset
CDMA Techniques & Technologies
T_ADD,T_DROP,T_TDROPT_ADD,T_DROP,T_TDROP
Time
Ec/Io
SectorA Sector
B
Guard Time(T-TDROP)
Add Threshold (T_ADD)
DropThreshold (T_DROP)
Soft Handoff Region
T_ADD, T_DROP and T_TDROP affect the percentage of MS in handoff.
T_ADD & T_DROP is the standards used to add or drop a pilot.
T_DROP is a timer.
CDMA Techniques & Technologies
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Comparison ThresholdComparison Threshold
Pilot P1
Pilot P2
Pilot P0
t0
T_COMP0.5dB
t1 t2
T_ADD
Pilot strength
P0-Strengh of Pilot P0 in Candidate Set.P1,P2-Stength of Pilot P1,P2 in Active Set.
t0-Pilot strength Measurement Message Sent, P0>T_ADD
t1-Pilot strength Measurement Message Sent, P0>P1+T_COMP*0.5dB
t2 -Pilot strength Measurement Message Sent, P0>P2+T_COMP*0.5dB
CDMA Techniques & Technologies
Transition Between Pilot SetsTransition Between Pilot Sets
T_ADD
T_DROP
Pilot 1
Pilotstrength
Pilot 2
T_TDROP
NeighborSet
CandidateSet
ActiveSet
CandidateSet
NeighborSet
TIME1 2 3 4 5 6 7
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Transmit DiversityTransmit Diversity
Time diversity
Block interleaving, error-correction
Frequency diversity
The CDMA signal energy is distributed on the whole 1.23MHZ
bandwidth.
Space diversity
The introduction of twin receive antennas .
The RAKE receivers of the mobile station and the base station
can combine the signals of different time delay.
During a handoff, the mobile station contacts multiple base
stations and searches for the strongest frame
CDMA Techniques & Technologies
Transmission DiversityTransmission Diversity
The forward transmission diversity types in
CDMA2000 1X are
TD (Transmit Diversity)
OTD (Orthogonal Transmit Diversity)
The data stream is divided into two parts, which will be spread
by the orthogonal code sequence, and transmitted by two
antennas.
STS (Space Time Spreading)
All the forward code channels are transmitted by the multi-
antennas.
CDMA Techniques & Technologies
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Transmission DiversityTransmission Diversity
The Transmission Diversity Technology enhances the receive performance of MS.
Transmissiondiversity
processing
Data stream 1
Data stream 2
Data stream Restoring data stream
Path1
Path2
Antenna 2
Antenna 1
CDMA Techniques & Technologies
The Principle of RAKE ReceiverThe Principle of RAKE Receiver
RAKE antennas help to overcome on the multi-path fading and enhance
the receive performance of the system
Receive set
Correlator 1
Correlator 2
Correlator 3
Searcher correlatorCalculate the
time delay andsignal strength
Combiner The combinedsignal
tt
s(t) s(t)
CDMA Techniques & Technologies
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Course ContentsCourse Contents
Chapter 1 Introduction
Chapter 2 CDMA Techniques & Technologies
Chapter 3 CDMA Air interface
Chapter 4 CDMA Core Network
Physical Channel in IS-95APhysical Channel in IS-95A
Forward channel
Forward Pilot Channel
Forward Sync Channel
Forward Paging Channel
Forward Traffic Channel (including power control sub-
channel)
Reverse channel
Access Channel
Reverse Traffic Channel
CDMA Air Interface
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Pilot channel(all-zeros)
W064
Pilot ChannelPilot Channel
A pilot channel:
Assist mobile station to be connected with CDMA network
Handles multi-path searching
Provide the phase reference for coherent demodulation and help the mobile
station estimate the transmission power
The mobile station measures and compares the pilot channel powers from
the base stations during the handoff
Forward pilot channel is spread over W0 and modulated with short code directly
BTS transmits the pilot channel continuously
CDMA Air Interface
ToQPSK
coder
2.4kbps 4.8kbps 4.8kbps
Codesymbol
Repetitivecode
symbol
1.2kbps
Convolutionencoderr=1/2,K=9
symbolrepetition
Blockinterleaving
Sync Ch bits
W3264
Sync ChannelSync Channel
The sync channel is used by the mobile station to synchronize with
the network. W32 is used to spread Sync Channel.
The synchronization message includes:
Pilot PN sequence offset: PILOT_PN System time: SYS_TIME
Long code state: LC_STATE
Paging channel rate: P_RAT
Here note that, sync channel rate is 1200bps
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ToQPSK
coder
Pagingchannel bits
19.2/9.6Kbps 19.2kbps
19.2kbpsCode
symbol
9.6/4.8 kbps
Convolutionencoder
r=1/2,K=9
Symbolrepetition
Blockinterleaving
Paging channel addressmask
Longcode PN
generator
decimator
1.2288Mcps
19.2kbps
Repetitive
codesymbol
Paging ChannelPaging Channel
The paging channel transmits:
System parameters message
Access parameters
Neighbors list
CDMA channels list message
The paging channel accomplishes:
Paging to MS Assign traffic channel to MS
The frame length of a paging channel is 20ms
W1 ~ W7 are spared for the Paging Channels spreading
CDMA Air Interface
W164
Forward Traffic ChannelForward Traffic Channel
I Ch PN sequence (1.2288 Mcps)
PN 1.2288 Mcps
Repetitivesymbol
19.2kbps
8.6kbps9.6kbps
4.8kbps
2.4kbps
1.2kbps
Add framequality indicatorbits(12,10,8,6)
Add 8encoded tail
bits
Convolutionencoder
r=1/2,K=9
Symbolrepetition
Forward trafficchannal
(172/80/40 or16bits/frame)
Blockinterleaver
19.2kbps
MUX
Long codegenerator
Power control bits
Q Ch PN sequence (1.2288 Mcps)
Basebandfilter
I(t)
Q(t)decimator
+QPSK Modulation
4.0kbps2.0kbps0.8kbps
19.2ksybps
9.6ksybps
4.8ksybps
2.4ksybps
Sin(2pfct)
Cos(2pfct)
is used to transmit data and signaling information.
Walsh code
CDMA Air Interface
decimator
+
+Baseband
filter
+
+
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Reverse Access ChannelReverse Access Channel
4.8 kbps (307.2kbps)
PN chips1.2288 McpsOrthogonal spreading
Repetitivesymbol
28.8 kbps
Codesymbol
14.4 kbps4.4 kbps 4.8kbpsAdd 8encoder tail
bits
Convolutionencoder
r=1/3,K=9
SymbolrepetitionAccess
channel(80 bits/frame)
Blockinterleaving
28.8 kbps
Data burstrandomizer
Long codePN
generator
Frame rate
Long code mask
Repetitivesymbol
used by MS to initiate communication or respond to Paging Channel
Walsh code
CDMA Air Interface
I Ch PN sequence (1.2288 Mcps)
Basebandfilter
I(t)
Q(t)
QPSK Modulation
Sin(2pfct)
Cos(2pfct)
+
+Baseband
filter
+
+
Q Ch PN sequence (1.2288 Mcps)
1/2 PN chips Delayedtime=406.9ns
Reverse Traffic ChannelReverse Traffic Channel
used to transmit data and signaling information
CDMA Air Interface
8.6kbps9.6kbps
4.8kbps
2.4kbps
1.2kbps
Add framequality indicatorbits(12,10,8,6)
Add 8encoded tail
bits
convolutionencoder
r=1/3,K=9
Symbolrepetition
Reverse trafficchannel
(172/80/40 or16 bits/frame)
Blockinterleaver
4.0kbps2.0kbps
0.8kbps
28.8Ksybps
14.4Ksybps
7.2Ksybps
3.6Ksybps
4.8 kbps (307.2kbps)PN chips
1.2288 McpsOrthogonal spreading
Data burstrandomizer
Long codePN
generator
Frame rate
Long code mask
Walsh code
I Ch PN sequence (1.2288 Mcps)
Basebandfilter
I(t)
Q(t)
QPSK Modulation
Sin(2pfct)
Cos(2pfct)
+
+Baseband
filter
+
+
Q Ch PN sequence (1.2288 Mcps)
1/2 PN chips Delayedtime=406.9ns
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Initialization of the MSInitialization of the MS
Synchronous Channel message contains the LC_STATE,
SYS_TIME, P_RAT, and synchronizes with the system.
CDMA Air Interface
BTS
Pilotch
annel
Synchr
onousc
hannel
Paging
channe
l
Access
channe
l
CDMA2000 Forward ChannelCDMA2000 Forward Channel
Forward CDMA2000 channel
F-CACH F-CPCCH F-PICH F-CCCH
F-DCCH F-FCH
F-PC F-SCCH F-SCH
F-PICH F-TDPICH F-APICH F-ATDPICH
F-SYNCH F-TCH F-BCH F-PCH F-QPCH
subchannel (RC1~2) (RC3~9)
Note: Only the channels with black color are being implemented in
Huawei equipment. The function of F-PICH, F-SYNCH, F-FCH, F-PC,F-SCCH, F-PCH are the same as those of IS95. We will only discuss
F-SCH, F-QPCH F-DCCH in the following slides.
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Forward channelForward channel
These channels are newlydefined in CDMA2000 system.
CDMA physical channels are classified in common channels and dedicated channels:Common physical channels:
Forward Pilot Channel(F-PICH)
Forward Synchronous Channel(F-SYNC)
Forward Paging Channel(F-PCH)
Forward Broadcast Control Channel(F-BCCH)
Forward Quick Paging Channel(F-QPCH)
Forward Common Power Control Channel(F-CPCCH)
Forward Common Assignment Channel(F-CACH)
Forward Common Control Channel(F-CCCH)
These channels are compatiblewith IS-95 system
Dedicated physical channel:
Forward Dedicated Control Channel(F-DCCH)
Forward Fundamental Channel(F-FCH)
Forward Supplemental Channel(F-SCH)
These channels are used to establish the connection between a base station and a
specific mobile station.
The CDMA2000 system adopts multiple data rates and the different combinations of
channels can achieve a performance superior to that in IS-95 system.
CDMA Air Interface
F-QPCHF-QPCH
It transmits OOK-modulated signal which can be demodulated by
MS simply and rapidly.
The channel adopts 80ms as a QPCH timeslot. Each timeslot is
divided into paging indicators, configuration change indicators
and broadcast indicators, all of which are utilized to inform the
MS whether to receive paging message, broadcast message or
system parameters in the next F-PCH.
Rapid and simple demodulation. MS no need to monitor F-PCH
for long time, so the standby time is prolonged.
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F-SCHF-SCH
F-SCH is typically used for high speed data
applications, while F-FCH is used for common
voice and low speed data application.
When a data call is established, firstly, F-FCH will
be allocated to the user. If the speed of data for
user exceeds 9.6kbps, F-SCH will be allocated.
CDMA Air Interface
F-DCCHF-DCCH
It is used for the transmission of specific user
signaling information during a call.
Each forward traffic channel may contain one F-DCCH.
Support 5ms frame.
Support discontinuous transmission.
CDMA Air Interface
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Forward Radio Configuration (RC)Forward Radio Configuration (RC)
Radio Configuration(RC):
A set of Forward Traffic channel and Reverse Traffic Channel transmission
formats that are characterized by physical parameters such as data rates,
modulation characteristics, and spreading rate.
Spreading Rate: Equivalent to chips rate, e.g., 1.2288Mcps.
RadioConfiguration
SpreadingRate
Max Data Rate*(kbps)
Effective FECCode Rate
OTDAllowed
FEC Encoding Modulation
1** 1 9.6 1/2 No Conv. BPSK
2** 1 14.4 3/4 No Conv BPSK
3 1 153.6 1/4 Yes Conv and Turbo QPSK
4 1 307.2 1/2 Yes Conv and Turbo QPSK
5 1 230.4 3/8 Yes Conv and Turbo QPSK
6 3 307.2 1/6 Yes Conv and Turbo QPSK
7 3 614.4 1/3 Yes Conv and Turbo QPSK
8 3 460.8 1/4 or 1/3 Yes Conv and Turbo QPSK
9 3 1036.8 1/2or 1/3 Yes Conv and Turbo QPSK
**Same as IS95
CDMA Air Interface
Reverse ChannelReverse Channel
Reverse CDMA2000 channel
R-ACHR-TCH
operation(RC1~2)
R-EACHoperation
R-CCCHoperation
R-SCCH
R-FCH
R-TCHoperation(RC3~6)
R-EACH
R-PICH
R-CCCH
R-PICH
R-DCCH
R-PICH
0~7 0~1
R-SCH
R-FCH
0~2
0~1
subchannel
R-PC
Only the channels in dark color are used in Huawei
equipment. The function of R-ACH,R-FCH,R-SCCHare the same as those in IS95. We will only discuss
R-PICH,R-SCH in the following slides.
CDMA Air Interface
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Types of Reverse ChannelTypes of Reverse Channel
Reverse channel includes reverse common channel
and reverse dedicated channel.
Reverse common channel:
Reverse Access Channel(R-ACH)
Reverse Enhanced Access Channel(R-EACH)
Reverse Common Control Channel(R-CCCH)
Reverse Dedicated Channel
Reverse Pilot Channel(R-PICH)
Reverse Dedicated Control Channel(R-DCCH)
Reverse Fundamental Channel(R-FCH)
Reverse Supplemental Channel(R-SCH)
Reverse Supplemental Code Channel (R-SCCH)
CDMA Air Interface
MUX A
Pilot( all '0's)
Power Control Bit
Reverse Pilot Channel
R-PICHR-PICH
The Function of Reverse Pilot Channel
Initialization
Tracing
Reverse Coherent Demodulation
Power Control Measurement
Base station enhances the received performance and
increases the capacity by means of coherent demodulation of
the Reverse Pilot Channel.
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Reverse ChannelsReverse Channels
Fundamental Channel: Fundamental Channel is used for the transmission of user
information to the base station during a call, and can be used to
transmit defaulted voice services as an independent Traffic
Channel.
Dedicated Control Channel
The Dedicated Control Channel is used for the transmission of
user and signaling information to a base station during a call.
Supplemental Channel/Supplemental Code Channel
These channels are used for the transmission of user information,
mainly data services, to the MS. The Reverse Traffic Channelcontains up to two supplemental channels and up to seven
supplemental code channels.
CDMA Air Interface
Reverse Radio Configuration (RC)Reverse Radio Configuration (RC)
RC: Radio Configuration
RC1~RC2:IS-95A/B
RC3~RC4:CDMA2000 1X
RC5~RC6: CDMA2000 3x
Radio
Configuration
Spreading
Rate
Max Data Rate*
(kbps)
Effective FEC
Code Rate
OTD
AllowedFEC Encoding Modulation
1** 1 9.6 1/3 No Conv 64-ary ortho
2** 1 14.4 1/2 No Conv 64-ary ortho
3 1 153.6 1/4 Yes Conv or Turbo BPSK
(307.2) (1/2)
4 1 230.4 3.8 Yes Conv or Turbo BPSK
5 3 153.6 1/4 Yes Conv or Turbo BPSK
(614.4) (1/3)
6 3 460.8 1/4 Yes Conv or Turbo BPSK
(1036.8) (1/2)
**Same as IS95
CDMA Air Interface
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RC 1
RC 2
RC 3
RC 4
RC 5
RC 1
RC 2
RC 3
RC 4
RC 5
RC 3
RC 4
RC 4
RC 3
F-FCH RCs
R-DCCH/SCHRCsF-DCCH/SCHRCs
R-FCH RCs
RC Combination RegulationRC Combination Regulation
RC1 and RC2 corresponds
respectively to rate set 1 and rate set
2 in IS- 95A/B system.
CDMA2000 Forward RC: RC1~RC5
Reverse RC: RC1~RC4
Rules:
Forward RC1, Reverse RC1
Forward RC2, Reverse RC2
Forward RC3 or RC4,Reverse RC3
Forward RC5, Reverse RC4
CDMA Air Interface
Course ContentsCourse Contents
Chapter 1 Introduction
Chapter 2 CDMA Techniques & Technologies
Chapter 3 CDMA Air Interface
Chapter 4 CDMA Number Planning
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Definition of Coverage AreasDefinition of Coverage Areas
Location area
MSC area
PLMN area
Service area
Sectorarea
CDMA Number Planning
Cell area
Parameters InvolvedParameters Involved
In a CDMA system, the following parameters are
defined to identify a user and his location:
MIN/IMSI
MDN
ESN
TLDN
SID/NID
LAI
GCI
SIN
SSN
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MIN/IMSIMIN/IMSI
Mobile subscriber identity/international mobile subscriber identityFor example, 0907550001/460030907550001
Not more than 15 digits
3 digits 2 digits
IMSI
MCC MNC MSIN
NMSI
CDMA Number Planning
MDNMDN
CC + MAC + H 0H 1H 2H 3 + ABCD
International mobile subscriber DN
National valid mobile subscriber number
Mobile directory number
For example, 8613307550001
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ESNESN
A unique Electronic Serial Number (ESN) is used to identify single
MS. An ESN includes 32 bits and has the following structure:
31......24 23......18 17......0 bit
Manufacturers number retained equipment SN
For example, FD 03 78 0A (the 10th Motorola 378 mobile phone)
The equipment serial number is allocated by a manufacturer.
CDMA Number Planning
TLDNTLDN
+CC MAC H0H 1H2 ABC+ ++44
Temporary local directory number
For example, 8613344755001
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SID/NIDSID/NID
MSCID (Exchange Identity)
= System Identity (SID) + Exchange number (SWIN)
is used to represent a certain set of equipment in an
NSS network. For example,
Unicom CDMA Shenzhen MSC is labeled as 3755+01
CDMA Number Planning
Location Area Identity (LAI)Location Area Identity (LAI)
PAGING message is broadcast within a local area, the size ofwhich depends on traffic, paging bearer capability, signaling flow ,
etc.
Format: MCC+MNC+LAC
MCC: Mobile Country Code, 3 digits. For example, China is 460.
MNC: Mobile Network Code, 2 digits. For example, the MNC of
Unicom is 03.
LAC: Location Area Code, a 2-byte-long hexadecimal BCD code.0000 cannot be used with FFFE.
For example, 460030100
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Global Cell Identity (GCI)Global Cell Identity (GCI)
The unique ID of a cell in PLMN
Format: LAI+CI
CI: Cell Identity, a 2-byte-long hexadecimal BCD code,
pre defined by the engineering department. The first 3
digits and the last digit represent the base station
number and the sector number respectively. For an
omni-directional site, the last digit of CI is 0.
For example, 4600301001230 shows base station number
123 contains an omni-directional site
CDMA Number Planning
ReviewReview
Chips rate: 1.2288Mcps
IS-95A/B is a subset, RC1/RC2
Apply the coherent demodulation to the reverse pilot
channel
Forward transmit diversity: OTD and STS
Forward quick power control at 800HZ rate
Improve the standby time by introducing the quick paging
channel.
Variable frames: 5ms, 20ms, 40ms and 80ms Introduce TURBO code into channel encoding
The maximum rate of a physical layer is up to 307.2K
CDMA Technology
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Development of CDMA Standards in ChinaDevelopment of CDMA Standards in China
CDMA standards currently adopted in China are mainly
based on the USA standards with few alterations. For
example, in USA the emphasis is put on the dual service
support i.e. CDMA and AMPS compatibility, while in China
there is no such requirement. Therefore, the settings of
frequency and basic channels, IMSI and others parameters
need to be modified. Likewise, there is also the need to
modify network interface IS-41 series of standards.
Case study: China Unicom NetworkCase study: China Unicom Network
In China Unicom CDMA project, phase 1, a narrow-band CDMA
network, named IS-95B (enhanced IS-95) is being constructed.
With total capacity is 15,000,000, subscribers handling, covering
over 200 cities.
Currently, both nationwide and international roaming tests have
conducted successfully with the CDMA networks of HongKong,
South Korea and Japan via the TSI international gateway bureau.
Besides, a CDMA intelligent network will be constructed to
provide intelligent value-added services like Pre-Paid Charging(PPC) and Virtual Private Network (VPN) etc.
The whole CDMA20001X network was launched in air in the
second half of 2002.
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Why CDMA2000?Why CDMA2000?
Increase the system capacity
Forward quick power control
Forward transmit diversity: OTD,STS
Coherent modulation applied on the pilot channel.(about
3dB)
The introduction to Turbo code
The stronger ability to resist interference
The improved error-correcting encoding
(applying Turbo code in medium/high rate
data transmission)
Why CDMA2000?Why CDMA2000?
Support high rate SCH, with the maximum rate
of a single channel being up to 307.2kbps.
Improve the standby time
Use the quick paging channel
Forward compatibility
Radio-frequency part
Baseband part, such as RC
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SummarySummary
Brief Development History of MobileCommunication
Analog--digital--code division
Objectives of 3G and comparison of 3 systems
Technical features of CDMA
Key technologies: power control, soft handoff,RAKE receiver
and cell breath
Other technologies: source coding, channel coding,
interleaving, scrambling, spreading and modulation
Channel structure: pilot, synchronization, paging, access and
service
Technical features of CDMA2000 1X Walsh and Turbo codes
QuestionsQuestions
What power control modes are there in CDMA2000
system and how are they implemented?
Describe the soft handoff process?
Describe the process and functions of cell breath?
Describe the implementation process of service
channels (forward and reverse)?
Describe the technical features of CDMA2000?
Describe the initialization process of a mobile phone?
What are the functions of a long code, short codeand Walsh code in CDMA system?
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