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

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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-