a2 general description of 3g
Post on 05-Apr-2018
221 Views
Preview:
TRANSCRIPT
-
7/31/2019 A2 General Description of 3G
1/51
Wireless Curriculum Development Section
ISSUE
OWR00001 General Description of 3G
1.0
-
7/31/2019 A2 General Description of 3G
2/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Course Contents
Chapter 1 Introduction to IMT-2000
Chapter 2 CDMA Fundamental
Chapter 3 Performance Enhancement Methods
Chapter 4 WCDMA FDD Mode
-
7/31/2019 A2 General Description of 3G
3/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
1st Generation
1980s (analog)
2nd Generation
1990s (digital)
3rd Generation
current (digital)
3G provides:
Complete integrated service solutions High bandwidth Unified air interface Best spectral efficiency and a step towards PCS
AMPS
Analog to DigitalTACS
NMT
OTHERS
GSM
CDMAIS95
TDMAIS-136
PDC
UMTSWCDMA
CDMA2000
TD-SCDMA
Development of Mobile Communications
Voice to Broadband
-
7/31/2019 A2 General Description of 3G
4/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Standardization Course of ITU IMT-2000
1985: FPLMTS, renamed as IMT-2000 in 1996
1992: 230MHz spectrum was allocated in WRC92
1999.3: Key parameters of IMT-2000 RTT were completed
1999.11: Technical specifications of IMT-2000 RTT were
completed
2000: All the network standards of IMT2000 were
completed
Family concept was adopted in network part Standardization organizations such as 3GPP(1998.12),
3GPP2 (1999) were established
-
7/31/2019 A2 General Description of 3G
5/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Target of IMT-2000
Global uniform frequency band and standard, globalseamless coverage
High efficient spectrum utility
High quality of service, high security
Easy for evolution from 2G system
Providing multimedia service
Car speed environment: 144kbps
Walk speed environment: 384kbps
Indoor environment: 2048kbps
-
7/31/2019 A2 General Description of 3G
6/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Standards for 3G
3G system
CDMA2000
3GPP2
FDD mode
WCDMA
3GPPFDD/TDD mode
TD-SCDMA
CWTS
TDD mode
-
7/31/2019 A2 General Description of 3G
7/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Main CDMA 3G Proposals
Regional Standard
Organization(RSO)
Radio Transmission
Technology(RTT)
U.S. TIA(TR 45.5) cdma2000
T1 W-CDMA
Korea TTA TTA1(~cdma2000)
TTA2(~W-CDMA)
Japan ARIB W-CDMA
Europe ETSI(SMG 2) W-CDMA
China CWTS TD-SCDMA
-
7/31/2019 A2 General Description of 3G
8/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Spectrum Allocation of IMT-2000
1850 1900 1950 2000 2050 2100 2150 2200 2250
ITU
Europe
USA MSSPCS
A D B BC D CE F A FE MSSReserveBroadcast auxiliary
2165 MHz1990 MHz
1850 1900 1950 2000 2050 2100 2150 2200
2250
1880 MHz 1980 MHz
UMTSGSM 1800 DECT MSS
1885 MHz 2025 MHz
2010 MHz
IMT 2000
MSSUMTS
Japan MSSIMT 2000MSSIMT 2000PHS
1895
1918
BC
1885
A A
2170 MHz
IMT 20002110 MHz 2170 MHz
MSS MSS
CDMATDDWLL
FDDWLL
1980
2025MHz
GSM1800
CDMAFDDWLL
1960
1920
1945
China
cellular(1) cellular(2) cellular(2)
1805 MHz
1865
1865
1870
1885
1890
1895
1910
1930
1945
1965
1970
1975
-
7/31/2019 A2 General Description of 3G
9/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
3G Spectrum (After WARC2000)
1850 1900 1950 2000 2050 2100 2150 2200 2250
Reserve
UMTSGSM 1800
DECT MSS
MSSIMT 2000PHS MSSIMT 2000
IMT 2000
MSSIMT 2000IMT 2000
IMT 2000
MSSUMTS
MSS
A D B E F A B C
MSS
MSS MSS
[GSM 1800, PCS]
FEB BC
ITU Identifications
Europe
China**
Japan,
Korea (w/o PHS)
Americas***
1700 1750 1800950 1000800 850 900
IMT 2000IMT 2000
2500 2550 2600 2650 2700
IMT 2000
UMTS
GSM
Cellular
PDC
Cellular
MSS
GSM
IMT-
2000
IMT 2000
IMT 2000UPCS
PCS
* *
D
IMT 2000
-
7/31/2019 A2 General Description of 3G
10/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
QoS Requirements of Different Services
Time delay
Quality (BER)
background
conversational
streaming
interactive
-
7/31/2019 A2 General Description of 3G
11/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Course Contents
Chapter 1 Introduction to IMT-2000
Chapter 2 CDMA Fundamental
Chapter 3 Performance Enhancement Methods
Chapter 4 WCDMA FDD Mode
-
7/31/2019 A2 General Description of 3G
12/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Chapter 2 CDMA Fundamental
2.1 Radio Transmission Environment
2.2 Multiple Access Technology and
Duplex Technology
2.3 CDMA Principle and RAKE Technology
-
7/31/2019 A2 General Description of 3G
13/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Multi-path Environment
Time
Received
signal
Transmitted
signal
-
7/31/2019 A2 General Description of 3G
14/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Fading
Transmitted Signal
-40
-35
-30
-25
-20
-15
-10
-5
0
dB
Received Signal
-
7/31/2019 A2 General Description of 3G
15/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Fading
Distance(m)
Received Power(dBm)
10 20 30
-20
-40
-60
Slow fading
Fast fading
-
7/31/2019 A2 General Description of 3G
16/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Frequency Selection of Fading
NarrowbandSystem
Fading
Transmit Signal Received Signalff
P(f) P(f)
Fading
Transmit Signal Received Signalff
P(f) P(f)
BroadbandSystem
-
7/31/2019 A2 General Description of 3G
17/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Multi-path Characteristics of Mobile Channel
Electromagnetic transmission - reflection,scattering,diffraction
Signal fading can be divided into three parts in radio
environment:
Path loss: with big range of fading
Big scale fading:slow-speed, with middle range of fading, also
with logarithm normal distribution characteristic
Small scale fading: fast-speed, with small range of fading
Two typical types of small scale fading include:
Rayleigh distribution (not line-of-sight transmission)
Ricean distribution(line-of-sight transmission)
-
7/31/2019 A2 General Description of 3G
18/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Category of Typical Radio Channel
Static Channel
Indoor Channel
Outdoor-to-indoor pavement Channel
Vehicle mounted Channel
Moving Channel
Birth-death Channel
-
7/31/2019 A2 General Description of 3G
19/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Chapter 2 CDMA Fundamental
2.1 Radio Transmission Environment
2.2 Multiple Access Technology and
Duplex Technology
2.3 CDMA Principle and RAKE Technology
-
7/31/2019 A2 General Description of 3G
20/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Multiple Access Technology and DuplexTechnology
Multiple access technology
Time division multiple access (TDMA)
Frequency division multiple access (FDMA)
Code division multiple access (CDMA)
Duplex technology
Time division duplex (TDD)
Frequency division duplex (FDD)
-
7/31/2019 A2 General Description of 3G
21/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
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
Power
Power
Power
FDMA
TDMA
CDMA
Multiple Access Technology and DuplexTechnology
-
7/31/2019 A2 General Description of 3G
22/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Characteristics of CDMA System
High Spectral Efficiency
Frequency multiplex coefficient is 1.
soft capacity
Quality
Coverage
Interference
Self-interference system
A UE transmission power is interference for another UE.
-
7/31/2019 A2 General Description of 3G
23/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Processing Procedure of CDMA System
Sourcecoding
Channel
codingSpreading Modulation
Sourcedecoding
Channel
decoding Despreading Demodulation
Radio channel
-
7/31/2019 A2 General Description of 3G
24/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Chapter 2 CDMA Fundamental
2.1 Radio Transmission Environment
2.2 Multiple Access Technology and
Duplex Technology
2.3 CDMA Principle and RAKE Technology
-
7/31/2019 A2 General Description of 3G
25/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
correlation
Correlation is a measure of similarity of between any two
arbitrary signals.
EXAMPLE:
-1 1 -1 11 1 1 1
-1 1 -1 1Zero correlation
Orthogonal signals
-1 1 -1 1
-1 1 -1 -11 1 1 11 correlation
Identical signals
+10
-1+10-1
+1
0-1
+10-1
-
7/31/2019 A2 General Description of 3G
26/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
OVSF&Walsh
SF = 1 SF = 2 SF = 4
Cch,1,0 = (1)
Cch,2,0 = (1,1)
Cch,2,1 = (1,-1)
Cch,4,0 =(1,1,1,1)
Cch,4,1 = (1,1,-1,-1)
Cch,4,2 = (1,-1,1,-1)
Cch,4,3 = (1,-1,-1,1)
Creating the orthogonal code sequences
-
7/31/2019 A2 General Description of 3G
27/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Autocorrelation
Autocorrelation is related to the muti-path interference characteristic.
Delay time (chip)
Correlation
Delay time sequence correlation0 -1 -1 -1 1 1 -1 1 1
1 -1 -1 1 1 -1 1 -1 -1/72 -1 1 1 -1 1 -1 -1 -1/73 1 1 -1 1 -1 -1 -1 -1/74 1 -1 1 -1 -1 -1 1 -1/75 -1 1 -1 -1 -1 1 1 -1/76 1 -1 -1 -1 1 1 -1 -1/7
1
Example: -1 -1 -1 1 1 -1 1
-
7/31/2019 A2 General Description of 3G
28/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Configuration of Gold Sequence Generator
clong,1,n
clong,2,n
MSB LSB
Gold sequence is used as scrambling code in WCDMA
-
7/31/2019 A2 General Description of 3G
29/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Spreading and Despreading (DS-CDMA)
Spreading
Despreading
Chip
Symbol
Data
Spreading code
Spreading signal
=Datacode
Data
=Spreadingcode
1
-1
1
-1
1
-1
1
-1
1
-1
Spreading code
-
7/31/2019 A2 General Description of 3G
30/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Desired signal
Other users signal
Desired spreading signal
Spreading code
Data after despreading
Other spreading signal
Other signal after integration
1
-1
1
-1
1
-1
8
-8
1
-1
8
-8
Data after integration
Other signal after despreading
Spreading and Despreading (DS-CDMA)
-
7/31/2019 A2 General Description of 3G
31/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Spreading code
Spreading code
Signal
Combination
Spectrum Analysis of Spreading & Despreading
Narrowband signal
f
P(f)
Broadband signal
P(f)
f
Noise
P(f)
f
Noise+Broadband signal
P(f)
f
Recovered signal
P(f)
f
-
7/31/2019 A2 General Description of 3G
32/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Principle of RAKE Receiver
RAKE receiver 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)
-
7/31/2019 A2 General Description of 3G
33/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Structure of RAKE Receiver
Q
I
Combiner
I
MatchedFilter
PhaseRotator
Channelestimator
DelayEqualizer
I
Q
Path 1
Path 2
Path 3
Input signal
Correlator
Code
generators
Q
-
7/31/2019 A2 General Description of 3G
34/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Advantages of CDMA
RAKE receiver is adopted
The time diversity effect generated by channel coherence time isefficiently used.
frequency diversity
Wideband frequency spectrum
Higher interference tolerance and security performance Low signal transmission power
Great flexibility in carrying multiple services with largely different
bit rate and QoS requirement.
Different spreading factors for different services with different data
rates
High spectral efficiency
All users can share the same frequency spectrum simultaneously.
Supporting soft handover and softer handover.
-
7/31/2019 A2 General Description of 3G
35/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Course Contents
Chapter 1 Introduction to IMT-2000
Chapter 2 CDMA Fundamental
Chapter 3 Performance Enhancement Methods
Chapter 4 WCDMA FDD Mode
-
7/31/2019 A2 General Description of 3G
36/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Introduction to Diversity Technique
Reduce the effects of fading
fast fading caused by multipath
Slow fading caused by shadowing Improve the reliability of communication
Increase the coverage and capacity
Macroscopic diversity
Soft handover and softer handover Reduce large-scale fading
Microscopic diversity
Diversity technique is used to obtain uncorrelated
signals for combining
-
7/31/2019 A2 General Description of 3G
37/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Microscopic Diversity
Time diversity
Channel coding, Block interleaving, error-correction
Frequency diversity
The user signal is distributed on the whole bandwidth
frequency spectrum
Space diversity
Receive diversity
Transmit diversity
Polarization diversity
Vertical polarization
Horizontal polarization
-
7/31/2019 A2 General Description of 3G
38/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Basic Combining Methods
Maximal-Ratio Combiner The mutipath signals are weighted proportional to their
signal SNR and then summed.
Equal-Gain Combiner
Equal-gain combining is similar to maximal-ratiocombining, but there is no attempt to weight the signal
before addition.
Selection Combiner
Choose the signal with the highest instantaneous quality,
so the output quality is equal to that of the best incoming
signal.
-
7/31/2019 A2 General Description of 3G
39/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
WCDMA Rx/Tx Diversity
Forward link capacity is the bottle neck of CDMA cellular
system capacity. WCDMA standard has deeply researched
the application of transmission diversity. New transmit
diversity scheme has been put forward. It will improve
forward link capacity.
Open loop transmission diversity
transmit diversity based on space-time block coding (STTD)
Time switched transmit diversity on SCH (TSSD)
Closed loop transmission diversity, FBI domain
Site selection diversity(macro diversity) cell selection, FBI
domain
T itt A t Di it
-
7/31/2019 A2 General Description of 3G
40/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Transmitter Antenna Diversity
Based on Time-space Block Coding
b2b0 b1 b3
b0 b1 b2 b3
-b2 b3 b0 -b1
Antenna 1
Antenna 2
Channel bits
STTD encoded channel bits
for antenna 1 and antenna 2.
-
7/31/2019 A2 General Description of 3G
41/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Time Switched Transmit Diversity on SCH
Antenna 1
Antenna 2
acsi,0
acp
acsi,1
acp
acs
,1
acp
Slot #0 Slot #1 Slot #1
acs
,
acp
Slot #2
-
7/31/2019 A2 General Description of 3G
42/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Closed Loop Transmit Diversity
Spread/scramble
w1
w2
DPCHDPCCH
DPDCH
Rx
Rx
CPICH1
Tx
CPICH2
An
An
Tx
Weight Generation
w1 w2
Determine FBI message
from Uplink DPCCH
-
7/31/2019 A2 General Description of 3G
43/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Receiving Effects for Different Multi-path Diversity
-
7/31/2019 A2 General Description of 3G
44/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Smart Antenna
Wanted signal
interference
Reduce interference Increase coverage and capacity
-
7/31/2019 A2 General Description of 3G
45/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Smart Antenna
Omni antenna Directional antenna Smart antenna
-
7/31/2019 A2 General Description of 3G
46/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Course Contents
Chapter 1 Introduction to IMT-2000
Chapter 2 CDMA Fundamental
Chapter 3 Performance Enhancement Methods
Chapter 4 WCDMA FDD Mode
-
7/31/2019 A2 General Description of 3G
47/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Characteristics of WCDMA FDD
Channel bandwidth: 5MHz
Chip rate: 3.84Mcps
Frame length: 10ms
Voice coding: AMR (Adaptive Multi-Rate)
Uplink and downlink modulation: QPSK/QPSK
Coherence demodulation aided with pilot
Fast closed loop power control: 1500Hz
Handover: soft/hard handover
Support synchronous and asynchronous NodeB
operation
-
7/31/2019 A2 General Description of 3G
48/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Characteristics of WCDMA FDD
Satisfy the minimum performance requirement of IMT2000
Compatible with GSM-MAP core network
Comparatively steady version R99 has been released
Support open loop and closed loop transmit diversity mode
Support Common Packet Channel(CPCH) and Downlink Share
Channel, adapt to Internet data access mode
Support macro diversity, selection diversity of NodeB location
Support different fast power control algorithms and open loop,out loop power control
Fully support UE locating services
-
7/31/2019 A2 General Description of 3G
49/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
WCDMA Voice Evolution
Adopt AMR voice coding, and support voice quality of
4.75Kbps ~ 12.2Kbps
Adopt soft handover and transmit diversity to improve
system capacity
Provide high fidelity voice mode
Fast power control
-
7/31/2019 A2 General Description of 3G
50/51
Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal
Data Service Evolution of WCDMA
Support maximum 2Mbps data service
Support packet switch
Adopt ATM platform currently
Provide QoS
Common Packet Channel(CPCH) and Downlink Share
Channel(DSCH) can support Internet packet services better
Provide mobile IP service(dynamic allocation of IP addresses)
TFCI domain provides dynamic data rate Provide high-quality support for uplink-downlink symmetric
data service, such as voice, video phone, conference TV
-
7/31/2019 A2 General Description of 3G
51/51
top related