WCDMA Principles
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Transcript of WCDMA Principles
WCDMA PRINCIPLES
Chapter 1 WCDMA Fundamental & Key Technologies
Chapter 2 WCDMA RNP & RNO Principles
Multiple Access Technology
CDMA
WCDMA System Architecture
WCDMA SYSTEM PROCESSES
Source Coding
ChannelCoding Spreading Modulation Transmission
Source Decoding
ChannelDecoding Despreading Demodulation Reception
Bit Symbol Chip
Radio Channel
A/D Conversion
3 Steps:1. Block Coding2. Channel Coding3. Interleaving
Types of Channel Coding:1. Convolutional Coding- ½ or 1/32. Turbo Coding – 1/3
OVSF Codes
1. QPSK2. 16 QAM
>>next
SC
Interleaving
<<back
Spreading code
Spreading code
Signal Combination
Narrowband signalf
P(f)
Broadband signal
P(f)
f
Noise
P(f)
f
Noise+Broadband signal
P(f)
f
Recovered signal
P(f)
f
Spreading and Despreading
<<back
WCDMA Spreading Code: Walsh Code
Important Relations:SF is inversely proportional to SERVICE RATE.
SF = Chip Rate / Service Rate
Chip Rate is constant (3.84 Mcps)<<back
WCDMA Modulation
<<back
Multi-Path Environment
Fading
Rake Receiver
Chapter 1 CDMA Fundamental & Key Technologies
Chapter 2 WCDMA RNP & RNO Principles
WCDMA System Architecture
RAB, RB and RL
UE
Node B
RNC CN
RAB
RB
RL
Radio Interface Protocol Structure
C-Plane SignalingU-Plane Information
PDCP
PDCP
RLCRLC
RLCRLC
MAC
PHYSICAL
RLCRLC
RLCRLC
BMC
RRCCONTROL
CON
TRO
L
CON
TRO
LCON
TRO
L
CON
TRO
L
L1
TransportChannels
L2/MAC
LogicalChannels
L2/RLC
L2/BMC
L2/PDCP
Radio Bearers
L3
Iub Interface Protocol
WCDMA Radio Interface Channel Definition
• Logical Channel – information carrier• Transport Channel – characteristics of transmission• Physical Channel – specification of the information global content
Logical Channels:
Dedicated Traffic Channel (DTCH)
Common Traffic Channel (CTCH)
Broadcast Control Channel (BCCH)
Paging Control Channel (PCCH)
Dedicated Control Channel (DCCH)
Common Control Channel (CCCH)
Traffic Channel
Control Channel
WCDMA Radio Interface Channel Definition
Transport Channels:
Dedicated Channel (DCH) Dedicated Transport Channel
Broadcast Channel (BCCH)
Forward Access Channel (FACH)
Paging Channel (PCH)
Random Access Channel (RACH)
High-Speed Downlink Shared Channel (CCCH)
Common Transport Channel
WCDMA Radio Interface Channel Definition
Physical Channels:
P-CPICH – Primary Common Pilot Channel
P-CCPCH – Primary Common Control Physical ChannelSCH – Synchronization Channel
S-CCPCH – Secondary Common Control Physical Channel
PICH – Paging Indicator Channel
PRACH – Physical Random Access Channel
AICH – Acquisition Indicator Channel
DPDCH – Dedicated Physical Data Channel
DPCCH – Dedicated Physical Control Channel
HS-SCCH – High Speed Share Control Channel
HS-PDSCH – High Speed Physical Downlink Share Channel
HS-DPCCH – High Speed Dedicated Physical Control Channel
Node B UE
CELL BROADCAST CHANNELS
PAGING CHANNELS
RANDOM ACCESS CHANNELS
DEDICATED CHANNELS
HIGH SPEED DOWNLINK SHARE CHANNELS
UE Working Modes and States
CELL PCH
CELL FACHCELL DCH
URA PCH
DEAD
IDLE
RRC Connection
• Scan networks (PLMN)• Camp on a cell
• Monitors paging channel• Cell re-selection
• Common Channel• PS service with few data to transmit
• Reduce activity, DTX and save power
• Reduce activity further• Avoid unnecessary signaling
• Dedicated channel• Common service, such as voice
Paging
CN RNC1 RNC2 NODEB1.1 NODEB2.1 UE
RANAP RANAP
RANAP RANAP
PAGING
PAGING
PCCH PAGING TYPE 1
PCCH PAGING TYPE 1
PAGING TYPE 1
• The message is transmitted in one LA or RA according to LAI or RAI.• After calculating the paging time, the paging message will be transmitted at that time.• If UE is in CELL PCH or URA PCH state, the UTRAN transmits the paging information in PAGING TYPE 1 message to UE. After received paging message, UE performs a cell update procedure to transit state to CELL FACH.
Paging Type 2
CN RNC1
RANAP RANAP
RRC
PAGING
DCCH: PAGING TYPE 2
UE
RRC
• If UE is in CELL DCH or CELL FACH state, the message will be transmitted on DCCH with paging type 2.• The message will be transmitted in a cell.
Call Process
In WCDMA system, a call process includes the following basic signaling flows: RRC connection flow Direct transfer message flow Authentication flow (optional) Security flow (optional) RAB establish flow Call proceeding NAS signaling before correlative bearer release Correlative bearer release
Concepts about HandOver
“Make before break.”
• Soft handover: the signals from different NodeBs are merged in RNC• Softer handover: the signals from different cells, but from same NodeB are merged in NodeB.
Terminologies:
Active set – set of cells currently used by UE. Monitor set – set of cells that are not in the active set but are being observed by the UE based on the neighboring cell information from the UTRAN. Detected set – set of cells that have been detected by the UE but do not belong to the active set or the observation set.
-Thank you-