ee8315 lecture8 umts 2005 pa1
TRANSCRIPT
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UMTS
2005 H. Hmimy Lecture 9, Slide 1SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Southern Methodist University
EETS 8315 / TC752-N
Advanced Topics in Wireless Communications
Spring 2005
http://www.seas.smu.edu/eets/8315
Lecture 8: UMTS: system and network
Instructor: Dr. Hossam Hmimy, Ericsson Inc.
[email protected](972) 583-0155
UMTS
2005 H. Hmim Lecture 9 Slide 2SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Announcement
Graduating Students please send me email
confirming that you are graduating this semester.
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UMTS
2005 H. Hmimy Lecture 9, Slide 3SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
outline
UMTS History
UMTS spectrum
UMTS reference model and protocol stack UTRAN
Protocols and interfaces
components
Air interface (WCDMA)
Logical, transport and physical channels
...
UMTS
2005 H. Hmim Lecture 9 Slide 4SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
UMTS : History
Research Programs in Europe
RACE (Research in Advanced Communications Equipment)
Air interface
1988-1995
ACTS (Advanced Communications Technology and
Services)
1995-.
FRAMES (Future Radio Multiple Access Systems)
W-CDMA FDD
TDMA with and without spreading
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2005 H. Hmimy Lecture 9, Slide 5SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
UMTS : WCDMA
Chip rate 3.84Mcps
Modulation QPSK
BW 5MHz
Frame length 10msec
Multiple access WCDMA/FDD, TD-CDMA/TDD
15 TS per frame
UMTS
2005 H. Hmim Lecture 9 Slide 6SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
UMTS Spectrum
In The US (?)
1700MHz / 2.2GHz
700MHz
1900MHz
W-CDMA
TDD
W-CDMA UL
FDD
W-CDMA
TDD
W-CDMA DL
FDD
MS MS
1900MHz
20 60 15 6030 3085
2200MHz
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UMTS
2005 H. Hmimy Lecture 9, Slide 7SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
UMTS 3GPP
3GPP 99 introduction of UTRAN with separate CS & PS domains
no change in GPRS CN ( protocol stack)
New RAN
3GPP R4 (2001) Minor changes
3GPP R5 (2002) introduce GERAN. Traffic mainly PS,
change in CN ( Server and Media GW ) + IMS
signaling use IP based SIP session initiation protocol RFC 2543
HSDPA
3GPP R6 (2004) HSDPA UL Enhancement
Multimdia Broadcast Multicast Service (MBMS)
Super 3G
UMTS
2005 H. Hmim Lecture 9 Slide 8SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
UMTS Architecture
UTRAN UMTS Terrestrial Radio Access NetworkCN Core Network
UE User Equipment
CN
UTRAN
UE
Uu
Iu
CN : Enhanced GSM/GPRS CN
RN: UTRAN
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UMTS
2005 H. Hmimy Lecture 9, Slide 9SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
UMTS reference model: R99
CSCF: responsible for call state control functions, serviceswitching function, address translation, vocoder negotiation
to support VoIP
3GSGSN 3GGGSN PSTN
GW
Roaming
GWHLR
CSCF
RAN
Applicationservices
2G network
IP
PSTNIu3G MSC
UMTS
2005 H. Hmim Lecture 9 Slide 10SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
UMTS Protocol Stack, user
Phy.
MAC
RLC
Phy.
IP
UDP
GTP-U
IP
Phy
L2
IP
Iu
SGSN GGSN
MS
IP
Phy.
MAC
RLC
PDCP
Phy.
L2
IP
UDP
GTP-U
IP relay
Phy.
ATM
AAL5/2
IP
UDP
GTP-U
L2
Phy.
ATM
AAL5/2
IP
UDP
GTP-U
IP relay
Node B + RNC
UTRAN
PDCP
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UMTS
2005 H. Hmimy Lecture 9, Slide 11SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
UMTS Protocol Stack, control
Phy.
MAC
RLC
Iu
SGSN GGSNMS
Phy.
MAC
RLC
Phy.
ATM
AAL5/2
SCCP
Node B + RNC
UTRAN
RRC
Phy.
ATM
AAL5/2
SCCP
Phy.
ATM
AAL5/2
SCCP
Phy.
ATM
AAL5/2
SCCP
Phy.
ATM
AAL5/2
SCCP
Signaling connection control part
UMTS
2005 H. Hmim Lecture 9 Slide 12SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
UMTS CN
R99
R5
See section 5.7 of the textbook pp 95-97.
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2005 H. Hmimy Lecture 9, Slide 13SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
UTRAN Architecture
UTRAN consists of
RNCs (similar to BSCs)
Node Bs (similar to BTSs)
RNS
RNC
RNS
RNC
Core Network
Node B Node B Node B Node B
Iu Iu
Iur
Iub IubIub Iub
UMTS
2005 H. Hmim Lecture 9 Slide 14SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Functions of UTRAN Components
RNC
Serving RNC (SRNC)
L2 functionality
Terminates RR control signaling and RANAP)
Uplink/downlink signal transfer, mobility, soft handoff, outerloop/ downlink power control,
Controlling RNC (CRNC)
Load and congestion control, admission and code allocation
Drift RNC (DRNC)
No L2 functionality.
Combining diversity
Routes the traffics from Iub to Iur transparently.
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2005 H. Hmimy Lecture 9, Slide 15SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Functions of UTRAN Components
Node B:
logical node, maintains link with UE
responsible for radio transmission for one or more cells,
adds/removes radio links on demand, mapping logical resources to physical resources,
inner loop power control,
interconnecting UE from different manufacturers.
UMTS
2005 H. Hmim Lecture 9 Slide 16SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Protocol Model for UTRAN Interfaces
UTRAN consists of
Radio Network Layer (specific to UTRAN itself)
Transport Network Layer (standard technology: ATM)
The UTRAN specific protocols include Radio Access Network Application Part: Radio Network Signalling
over the Iu.
Radio Network Subsystem Application Part: Radio Network
Signalling over the Iur.
Iub interface uses node B application protocol (NBAP).
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2005 H. Hmimy Lecture 9, Slide 17SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
UTRAN Interfaces
Iur Interface (RNC RNC)
point-to-point open interface,
macro-diversity support,
transport signalling for mobility and radio resource allocation.
Iub Interface (RNC Node B)
interconnection of equipment from different manufacturers,
allows Abis (GSM/GPRS transmission sharing),
transports DCH, RACH, FACH and DSCH data,
enables negotiation of radio resources between node B and
RNC
RNC
RNC
Node
B
Node
B
Node
B
Iur
Iub
Iu
UMTS
2005 H. Hmim Lecture 9 Slide 18SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Protocol Model for UTRAN Interfaces
Signaling applications
NBAP
RNSAP
RANAP
Phy.
ATM
AAL5MTP3-B
SCCP
RANAP
Phy.
ATM
AAL5
MTP3
SCCP
RNSAP
Iu
Iur
SSCOPSCCF-NNI
Phy.
ATM
AAL5
NBAP
SSCOP
SCCF-NNI
IubSSCOP:Service specific Connection oriented protocolSSCF: service specific Convergence function
NNI: net to net interface
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2005 H. Hmimy Lecture 9, Slide 19SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Protocol Model for UTRAN Interfaces
User Data (traffic)
Phy.
ATM
AAL2/5
IP
UDP
IP data
Phy.
ATM
AAL2/5
Iur Data
IuIur
Phy.
ATM
AAL2
Iub
Logical ch.
data
GTP-U
UMTS
2005 H. Hmim Lecture 9 Slide 20SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Physical Layer
Physical layers consists of
physical channel
transport channel
Physical layer provides Encoding / decoding of transport channels
multiplexing/de-multiplexing of transport channels
mapping transport channels onto physical channels
RF Processing (modulation/demodulation, spreading/de-
spreading)
Closed loop power control
Macro-diversity Distribution/Combining
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2005 H. Hmimy Lecture 9, Slide 21SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
WCDMA Features
Soft Handoff
communicate with multiple base stations
Multipath Receptionrake receivers provide diversity gain
Fast Power Control
combats near-far problem
Frequency Reuse of 1
simplifies frequency planning
Soft Capacity
flexible coverage and capacity palnning
UMTS
2005 H. Hmim Lecture 9 Slide 22SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Despreading
User
data
Code
Chip
sequence
0 1
1 1 0 0 1 1 0 0
+1
0
-1
+1
0
-1
+1
0
-1
Spreading1 1 0 0 1 1 0 0
+1
0
-1
+1
0
-1
+1
0
-1
Case 1
1 0 1 0 1 0 1 0
+1
0
-1
+1
0
-1
+1
0-1
Case 2
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2005 H. Hmimy Lecture 9, Slide 23SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
BS 1 BS 2
Fully loaded system
Unloaded system
Cell breathing
UMTS
2005 H. Hmim Lecture 9 Slide 24SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Multipath Propagation
10
2
3
Time Dispersion
10 2 3
Radio Environment
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2005 H. Hmimy Lecture 9, Slide 25SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
C
O
M
B
I
N
E
R Power measurements
of neighbouring BS
Sum of individual
multipath components
Finger #1
Finger #2
Finger #3
Searcher Finger
Finger #N
Buffer/delay
CorrelatorsChannel
The RAKE-receiver principle
UMTS
2005 H. Hmim Lecture 9 Slide 26SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Power Control
What?
The Transmitter adapts the output power according to Path
Loss
Why? Mainly to solve the Near-Far problem
Goal is that all users should experience the same SIR
No PC on pilot or some CCCH
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2005 H. Hmimy Lecture 9, Slide 27SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Power Control ..
Open Loop Power control (Initially, No signaling)
UL
UE measure pilot,
read Interference level from BCH,
TX at calculated power,
Ramp up power
DL
BS calculate required power,
Tx at calculated power,
Ramp up Power
UMTS
2005 H. Hmim Lecture 9 Slide 28SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Power Control ..
Inner Loop Power control UL/DL (fast)
For a fixed SIR target per service (RAB), UE or Node-B will
use:
Signaling channel, TCP, continuously @ rate 1500 times/s,
To relatively changes (up or down) the power to reach the
SIR target.
Outer loop Power control (Slow)
If the BLER measured (DL @ UE, UL@RNC) is below/
above the target,
UE/RNC increase/reduce SIR target.
Use the new target for the Inner loop PC.
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2005 H. Hmimy Lecture 9, Slide 29SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Handover
Inter-Radio Access Technology (IRAT) Handover
Traffic and Control Channels are Disconnected and must be
Reconnected
Inter-frequency Handover Traffic and Control Channels are Disconnected and must be
Reconnected
Soft Handover
Unique to CDMA
During Handover, the MS has traffic connections with two BSs
Softer Handover
between two sectors of the same site, with identical timing
UMTS
2005 H. Hmim Lecture 9 Slide 30SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Soft Handover Add/Drop/Replace
Thresholds
Soft Handover Measurement and Decision
Cell 1Connected
Add Cell 2Replace Cell 1
with Cell 3
time
Drop Cell 3
EC/ N0
Cell 1
Cell 2
Cell 3
T_ADD
T_REPLACE
t t t
T_DROP
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2005 H. Hmimy Lecture 9, Slide 31SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Channelization and scrambling codes
Channelization code
UL: separation of data
(DPDCH) and control(DPCCH) in same UE
DL separation of DLconnection of differentusers
UL 4-256 chips, DL 4-512chips
# of codes under one SC=SF
OVSF Responsible for spreading
Scrambling codes SC
UL separation of Users
DL separation of sectors
UL 38400 or 256 chips, DL
38400 chips
UL Millions, DL 512
Long gold code
Does not do spreading.
UMTS
2005 H. Hmim Lecture 9 Slide 32SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Unusable code
Channelization Code tree
Adapts user bit-rate to code length (figure 4-11)
C2.1 = {1 1}
C4.2 = {1 1-1-1}
C8.3 = {11-1-111-1-1}
C8.4 = {11-1-1-1-111}
SF = 2 SF = 4 SF = 8
Unusable codesC2.1 = {1 1}C4.1 = {1111}
UsingC4.1 C8.1 = {11111111}
C8.2 = {1111-1-1-1-1}
UsingC8.4
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2005 H. Hmimy Lecture 9, Slide 33SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Complex SC
Complex SC (Downlink)
I
Q
SC-Q
SC-I
FIR
Filter
FIR
Filter
cos ( 2fRFt)
sin ( 2fRFt)
SC-I
RFOutput
( )QIS
QIS
SCISCQQ
SCQSCII
+=
=
Is
Qs
3GPP TS 25.212 53GPP TS 25.212 5
UMTS
2005 H. Hmim Lecture 9 Slide 34SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
WCDMA Code Types
Synchronization Codes
Primary Sync. Code: Fixed 256-bit code
Unmodulated fixed for all cells
Helps UE identify the presence of a WCDMA BS
Helps UE achieve Slot Synchronization Secondary Sync. Codes: 256-bit codes
Unmodulated different for different cells ( group 64)
Helps UE achieve Frame and slot Synchronization
Pilot Codes
Common (CPICH) provides coherent reference for UE
receiver
Pilot bits embedded into each time slot of the DCH
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2005 H. Hmimy Lecture 9, Slide 35SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
WCDMA Channels
Logical
Transport
Characterize how data is transmitted
Provide services to the upper layer
Mapped to physical channels
Common transport channel
Dedicated transport channels
Physical
Carry one or more transport channels
Responsible for transporting data over the air.
Identified by carrier frequency, orthogonal code, relative phase
A super frame consists of 72 radio frames.
One radio frame is
10 milliseconds in duration
divided into 15 time slots
each slot has a duration of 0.625 milliseconds
UMTS
2005 H. Hmim Lecture 9 Slide 36SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Downlink Logical Channels Common Downlink Logical Channels
BCCH (Broadcast Control Channel)
Broadcasts cell site and system identification to all UE
PCCH (Paging Control Channel)
Transmits paging information to a UE when the UEs location is
unknown CCCH (Common Control Channel)
Transmits control information to a UE when there is no RRCConnection
CTCH (Common Traffic Channel)
Traffic channel for sending traffic to a group of UEs.
Dedicated Downlink Logical Channels
DCCH (Dedicated Control Channel)
Transmits control information to a UE when there is a RRCConnection
DTCH (Dedicated Traffic Channel)
Traffic channel dedicated to one UE
3GPP TS 25.301 5.3.1.13GPP TS 25.301 5.3.1.1
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2005 H. Hmimy Lecture 9, Slide 37SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Uplink Logical Channels Common Uplink Logical Channels
CCCH (Common Control Channel)
Transmits control information to a UE when there is no RRC Connection
CTCH (Common Traffic Channel)
Traffic channel for sending traffic to a group of UEs.
Dedicated Uplink Logical Channels
DCCH (Dedicated Control Channel)
Transmits control information from a UE when there is a RRC Connection
DTCH (Dedicated Traffic Channel)
Traffic channel dedicated from one UE
3GPP TS 25.301 5.3.1.13GPP TS 25.301 5.3.1.1
UMTS
2005 H. Hmim Lecture 9 Slide 38SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Downlink Transport Channels
Common Downlink Transport Channels BCH (Broadcast Channel)
Continuous transmission of system and cell information
PCH (Paging Channel)
Carries control information to UE when location is unknown
Pending activity indicated by the PICH (paging indication channel)
FACH (Forward Access Channel)
Used for transmission of idle-mode control information to a UE
No closed-loop power control
DSCH (Downlink Shared Channel)
Carries dedicated control and/or traffic data; shared by several UEs
Dedicated Downlink Transport Channels
DCH (Dedicated Channel) Carries dedicated traffic and control data to one UE
3GPP TS 25.301 5.2.1.13GPP TS 25.301 5.2.1.1
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2005 H. Hmimy Lecture 9, Slide 39SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Uplink Transport Channels
Uplink Transport Channels
Common Uplink Transport Channels
RACH Random Access Channel
Carries access requests, control information, short data Uses only open-loop power control
Subject to random access collisions
CPCH Uplink Common Packet Channel
Carries connectionless packet data to PCPH
Dedicated Uplink Transport Channels
DCH Dedicated Channel
Carries dedicated traffic and control data from one UE
UMTS
2005 H. Hmim Lecture 9 Slide 40SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Physical channels
PCCPCH
Fixed rate of 32 kpbs and SF=256
Transmitted continuously over an entire cell
No transmission during the 1st 256 chips within every slot of
radio frames
Secondary CCPCH
Variable rate
Discontinuous transmission
Supports narrow transmission with in a cell based on
configuration and use.
DPDCH ( Dedicated Phys. Data Channel)
DPCCH ( Dedicated Phys. Control channel)
CPICH (common pilot)
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2005 H. Hmimy Lecture 9, Slide 41SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
WCDMA Downlink Physical Channels
Common Downlink Physical Channels P-CCPCH Common Control Physical Channel (Primary)
Broadcasts cell site information
Broadcasts cell SFN; Timing reference for all DL
32kbps SF 256 continues transmission
SCH Synchronization Channel Fast Synch. P frame, S slot, time-multiplexed with P-CCPCH
S-CCPCH Common Control Physical Channel (Secondary)
Transmits idle-mode signaling and control information to UEs
Variable rate, with DTX
P-CPICH Common Pilot Channel
S-CPICH Secondary Common Pilot Channel (for sectored cells)
PDSCH Physical Downlink Shared Channel
Transmits high-speed data to multiple users
Dedicated Downlink Physical Channels DPDCH Dedicated Downlink Physical Data Channel
DPCCH Dedicated Downlink Physical Control Channel
Transmits connection-mode signaling and control to UEs
3GPP TS 25.2113GPP TS 25.211
UMTS
2005 H. Hmim Lecture 9 Slide 42SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
WCDMA Downlink Physical Channels
Downlink Indicator Channels
AICH (Acquisition Indicator Channel)
Acknowledges that BS has acquired a UE Random Access attempt
(Echoes the UEs Random Access signature)
PICH (Page Indicator Channel)
Informs a UE to monitor the next paging frame
AP-AICH (Access Preamble Indicator Channel
Acknowledges that BS has acquired a UE Packet Access attempt
(Echoes the UEs Packet Access signature)
CD/CA-ICH
Confirms that there is no ambiguity between UE in a Packet Access
attempt
(Echoes the UEs Packet Access Collision Detection signature)
Optionally provides available Packet channel assignments
CSICH
Broadcasts status information regarding packet channel availability
3GPP TS 25.2113GPP TS 25.211
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2005 H. Hmimy Lecture 9, Slide 43SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
WCDMA Uplink Physical Channels
Common Uplink Physical Channels
PRACH Physical Random Access Channel
Used by UE to initiate access to BS
PCPCH Physical Common Packet Channel
Used by UE to send connectionless packet data
Dedicated Uplink Physical Channels
DPDCH Dedicated Uplink Physical Data Channel
DPCCH Dedicated Uplink Physical Control Channel
Transmits connection-mode signaling and control to BS
3GPP TS 25.2113GPP TS 25.211
UMTS
2005 H. Hmim Lecture 9 Slide 44SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Common Pilot Channel
Downlink CPICH (Common Pilot Channel) (C256,0)
Pilot Symbol Data (10 symbols per slot)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 Frame = 15 slots = 10 mSec
1 timeslot = 2560 Chips = 10 symbols = 20 bits = 666.667 uSec
A A A A A A A A A A A A A A A A A A A A A AA A A
-A A A -A A -A -A A A -A -A A A -A -A A A -A -A A A -AA A -A
Slot 0 Slot 1Slot 14
Antenna 1Symbols
Antenna 2Symbols
If transmit diversity is used, then the pilot symbols are as shown for each antenna:
3GPP TS 25.211 5.3.33GPP TS 25.211 5.3.3
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2005 H. Hmimy Lecture 9, Slide 45SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Sync Channel /
Primary Common Control Channel Downlink SCH / P-CCPCH (C256,1 )
Broadcast Data (18 bits)SSCi
BCH Spreading Factor = 2561 Slot = 0.666 mSec = 18 BCH data bits / slot
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 Frame = 15 slots = 10 mSec
2304 Chips256 Chips
SCH BCH
3GPP TS 25.211 5.3.3.23GPP TS 25.211 5.3.3.2
PSC
UMTS
2005 H. Hmim Lecture 9 Slide 46SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Secondary Common Control Channel
Downlink S-CCPCH
Spreading Factor = 256 to 41 Slot = 0.666 mSec = 2560 chips = 20 * 2k data bits; k = [0..6]
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 Frame = 15 slots = 10 mSec
20 to 1256 bits0, 2, or 8 bits
3GPP TS 25.211 5.3.3.23GPP TS 25.211 5.3.3.2
DataTFCI or DTX Pilot
0, 8, or 16 bits
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2005 H. Hmimy Lecture 9, Slide 47SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Dedicated Control/Data Channel
Downlink DPCCH/DPDCH Frame
Data 2TFCIData 1 TPC
1 Slot = 0.666 mSec = 2560 chips = 10 x 2^k bits, k = [0...7]SF = 512/2k = [512, 256, 128, 64, 32, 16, 8, 4]
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 Frame = 15 slots = 10 mSec
DPDCH
Pilot
DPDCH DPCCH DPCCH
The DPDCH carries user traffic, layer 2 overhead bits, and layer 3 signaling data.
The DPCCH carries layer 1 control bits: Pilot, TPC, and TFCI
Downlink Closed-Loop Power Control steps of 1 dB, 0.5 dB
The DPDCH carries user traffic, layer 2 overhead bits, and layer 3 signaling data.
The DPCCH carries layer 1 control bits: Pilot, TPC, and TFCI
Downlink Closed-Loop Power Control steps of 1 dB, 0.5 dB
3GPP TS 25.211 5.3.23GPP TS 25.211 5.3.2
UMTS
2005 H. Hmim Lecture 9 Slide 48SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Uplink DPDCH/DPCCH
Uplink DPDCH/DPCCH
Coded Data, 10 x 2^k bits, k=06 (10 to 640 bits)
Dedicated Physical Data Channel (DPDCH) Slot (0.666 mSec)
Pilot FBI TPC
Dedicated Physical Control Channel (DPCCH) Slot (0.666 mSec)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 Frame = 15 slots = 10 mSec
I
QTFCI
DPCCH: 15 kb/sec data rate, 10 total bits per DPCCH slot
PILOT: Fixed patterns (3, 4, 5, 6, 7, or 8 bits per DPCCH slot)
TFCI: Transmit Format Combination Indicator (0, 2, 3, or 4 bits)
FBI: Feedback Information (0, 1, or 2 bits)
TPC: Transmit Power Control bits (1 or 2 bits); power adjustment in steps of 1, 2, or 3 dB
3GPP TS 25.211 5.2.13GPP TS 25.211 5.2.1
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UMTS
2005 H. Hmimy Lecture 9, Slide 49SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Downlink Data Coding, Multiplexing
Conv. Coding R=1/3
304
304
#2 344
688
688
#1 344
420
344 76
Radio frame FN=4N+1 Radio frame FN=4N+2 Radio frame FN=4N+3Radio frame FN=4N
Traffic data (122x2)per 20ms
Add CRC bits
Add Tail bits
2nd interleaving 420 420 420
344 76 344 76 344 76
#1 76 #2 76 #3 76 #4 76
804
260
244Tail 8
CRC16
360
112
Tail 896
96CRC 16
Rate matching
1st interleaving
Add CRC bits
Layer 3 Control data per 40ms
Add Tail bits
Conv. Coding R=1/3
#2 344#1 344Radio Frame
Segmentation
slot segmentation
30 ksps DPCH
Rate matching
1st interleaving
244
Traffic @ 12.2 kbpsTraffic @ 12.2 kbps L3 Data @ 2.4 kbpsL3 Data @ 2.4 kbps3GPP TS 25.101 App. A.3
3GPP TS 25.101 App. A.3
28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28
MUX: Pilot, TPC, TFCI 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12
600 bits (300 symbols) 600 bits (300 symbols) 600 bits (300 symbols) 600 bits (300 symbols)
Data from second 244-bit packet
UMTS
2005 H. Hmim Lecture 9 Slide 50SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Uplink Data Coding, Multiplexing
Turbo Coding R=1/3
360
9525
23160
11580
9600
9525 75
Radio frame FN=4N+1 Radio frame FN=4N+2 Radio frame FN=4N+3Radio frame FN=4N
Traffic data (3840x2)
2nd interleaving 9600 9600 9600
9525 75 9525 75 9525 75
75 75 75 75
11568
7712
3840
Termination
bits
CRC16
360
112
Tail 896
96
CRC 16
Rate matching
1st interleaving
Layer 3 Control data
Conv. Coding R=1/3
Frame Segmentation
slot segmentation
480 ksps DPDCH
1st interleaving
3840
Traffic @ 384 kbpsTraffic @ 384 kbps L3 Data @ 2.4 kbpsL3 Data @ 2.4 kbps3GPP TS 25.101 App. A.3
3GPP TS 25.101 App. A.3
9600 bits (9600 symb.) 9600 bits (9600 symb.) 9600 bits (9600 symb.) 9600 bits (9600 symb. )
3840
CRC16
3840
Concatenate Concatenate
Add CRC bits Add CRC bits
12 11568 12
Data from second 3840-bit packet
640 640 640 640 640 640 640 640 640 640 640 640
11580
9525 9525 9525
Frame Segmentation 90 90 90 90
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UMTS
2005 H. Hmimy Lecture 9, Slide 53SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Mapping DL Channels
BCCH CTCHPCCH CCCH DTCHDCCH Logical
BCH FACHPCH DCH DSCH transport
P-CCPCH DPDCHS-CCPCH DPCCH PDSCH Physical
UMTS
2005 H. Hmim Lecture 9 Slide 54SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Mapping UL Channels
CCCH DTCH DCCH Logical
RACH DCH DSCH transport
DPDCH DPCCH PCPCH PhysicalPRACH
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UMTS
2005 H. Hmimy Lecture 9, Slide 55SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Acquisition
On Power-up, the mobile attempts to find a
channel.
Node B send s exactly the same 256 chip code in
same slot (Primary SCH)
Mobile achieves slot level synchronization
After that, Mobile looks for the 10 msec frame.
Now Secondary SCH is searched.
There are 512 possible cell specific scrambling
codes divided in to 32 groups.
Mobile tries 16 possible codes in parallel.
UMTS
2005 H. Hmim Lecture 9 Slide 56SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
Downlink spreading and modulation
cch: Channelization codes (OVSF code, 4-256 chips)
cscramb: Downlink scrambling code (Gold code, 40960 chips)
p(t)
IQ
MuxDPDCH/DPCCH
cos(t)
p(t)
sin(t)cch cscramb
16*2K kbps 3.86 Mcps
OVSF codes ensure DL orthogonality even with different rates and
spreading factors for different users
DPCCH - dedicated packet control channel DPDCH - dedicated packet data channel
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UMTS
2005 H. Hmimy Lecture 9, Slide 57SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
Uplink Spreading and Modulation
cDPDCH
p(t)
IQ
Mux
I
I+jQ
Re { }
Q
DPDCH
DPCCH Im { }
cos(t)
p(t)
sin(t)
cscramb cscramb(optional)
cDPCCH
cDPDCH, cDPCCH: Channelization codes (OVSF codes, 4-256 chips)
cscramb: Primary scrambling code (VL Kasami code, 256 chips)
cscramb: Secondary scrambling code (Gold code, optional, 40960 chips)
16*2K kbps 3.86 Mcps
Additional DPDCHs may be added to either I or Q (multi-code transmission)
DPCCH - dedicated packet control channel DPDCH - dedicated packet data channel
UMTS
2005 H. Hmim Lecture 9 Slide 58SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
MODULATION
UTRA uses a base spreading rate of 3.84 Mcps in
5 MHz bandwidth
Variable data rates are provided
QPSK Modulation (I and Q components) Reverse-link Mapping DPDCH -> I and DPCCH ->
Q.
Forward-link: DPDCH & DPCCH are time
multiplexed into I & Q components.
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UMTS
2005 H. Hmimy Lecture 9, Slide 59SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
FDD vs. TDD
FDD Option allows continuous transmission in
both directions requires a paired frequency band
suited for symmetric bandwidth needs
TDD Option same carrier frequency is utilized for
uplink/downlink transmission (using time
division) works with unpaired frequency band
suited for asymmetric applications
easier to obtain spectrum
UMTS
2005 H. Hmim Lecture 9 Slide 60SMU EETS 8315 Advanced To ics in Wireless Communications - S rin 05
TDD Frame Structure
4.096
Mchi /s
time
frequency
625 s
10 ms
Figure 1: The TDD frame structure
10 ms
Single-switching-point configuration (symmetric DL/UL allocation)
10 ms
Single-switching-point configuration (asymmetric DL/UL allocation)
Figure 2: TDD frame structure examples
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UMTS
2005 H. Hmimy Lecture 9, Slide 61SMU EETS 8315 Advanced Topics in Wireless Communications - Spring05
References
UMTS Networks by H. Kaaranen et al 2001 chapter 4, 5, 9
http://www.ericsson.com/review/1999_03/files/1999031.pdf
S. Nanda, et al, Adaptation techniques in wireless packet data servicesIEEE communications magazine, January 2000.
M. Zeng, et al, Harmonization of global third generation Mobile systems,
IEEE communications magazine, December 2000.
UMTS
Reading assignment
Chapter 5, 6 , 7