14th June 2006 RANDAXHE Benjamin 1Thanks to M CATTRYSSE Eric

2

Presented by Randaxhe Benjamin

In order to receive

Electronics Bachelor Diploma

(Telecommunication oriented)

Academic year : 2005 ~ 2006

Memoir

UMTS, air interface et modulation

Presented by Benjamin Randaxhe

RANDAXHE Benjamin 414th June 2006

UMTSOverview

Air interfaceGeneralityCodingPower

ModulationUMTS modulatorRAKE receiver

RANDAXHE Benjamin 514th June 2006

UMTSOverview

Air interfaceGeneralityCodingPower

ModulationUMTS modulatorRAKE receiver

RANDAXHE Benjamin 614th June 2006

Universal Mobile Telecommunications System3rd generation mobile

Multimedia services

High bitrateNew services : Video Call, TV,internet browsing, games,…

RANDAXHE Benjamin 714th June 2006

RANDAXHE Benjamin 814th June 2006

UMTSOverview

Air interfaceGeneralityCodingPower

ModulationUMTS modulatorRAKE receiver

RANDAXHE Benjamin 914th June 2006

11

1

1

1

11

1

1

1

1

1

1

UMTS

Frequency is used

in every cell

Dissociation by code=> CDMA

Two codes are used Channelisation Scrambling

=> WCDMA

RANDAXHE Benjamin 1014th June 2006

RANDAXHE Benjamin 1114th June 2006

Time

Frequency

Power

Uplink Spectrum Downlink Spectrum1920 MHz 1980 MHz 2110 MHz 2170 MHz

Duplex Spacing : 190MHz

5 MHz 5 MHz

UMTS USER 1

UMTS USER 2

Full duplexSeparate frequencies used for uplink and downlink traffic

RANDAXHE Benjamin 1214th June 2006

UMTSOverview

Air interfaceGeneralityCodingPower

ModulationUMTS modulatorRAKE receiver

RANDAXHE Benjamin 1314th June 2006

Channelisation OVSF Separation of

channels

Scrambling Pseudo Noise codes Separation of

transmitters : MS or Node B

Modulator

Channelisation Scrambling

Clock

Data + CRC +…

bits chips

RANDAXHE Benjamin 1414th June 2006

User 3

Cchan 3

User 2

Cchan 2

User 1

Cchan 1

Cscr

UE1

UE2

UE3

RANDAXHE Benjamin 1514th June 2006

User 1

Cchan Cscr 1

UE1

UE2

UE3

User 2

Cchan Cscr 2

User 3

Cchan Cscr 3

RANDAXHE Benjamin 1614th June 2006

UMTSOverview

Air interfaceGeneralityCodingPower

ModulationUMTS modulatorRAKE receiver

RANDAXHE Benjamin 1714th June 2006

Everyone use the same frequencyAvoid interference between Node B ’s

themselvesAvoid « near-far effect »

UE

1 UE

2 UE

3

Power sent

UE

1

UE

2

UE

3

Power received

MAX

min

UE

1

UE

2 U

E

3

Power sent

UE

3

UE

2

UE

1

Power received

MAX

min

UE1

UE2

UE3

RANDAXHE Benjamin 1814th June 2006

Open loop Increases power step by step

Closed loopPower is regulated 1500 time per

second

RANDAXHE Benjamin 1914th June 2006

MSMS Node BNode B

SentSent 33 dBm (2W)-60 dBm (1 nanoW)

46 dBm (40W) 12 dBm (20mW)

ReceiveReceivedd

-117 dBm (1,9.10-

15W)-121 dBm (7,9.10-

16W)

NB: Thermal noise± -108 dBm (1,514 .10-14)

RANDAXHE Benjamin 2014th June 2006

UMTSOverview

Air interfaceGeneralityCodingPower

ModulationUMTS modulatorRAKE receiver

RANDAXHE Benjamin 2114th June 2006

Cscr

QPSK Modulator

DPDCH 1

SCH

DPDCH 2

DPDCH x

PDSCH

PCCPCH

SCCPCH

PICH

AICH

CPICH

DPCCH

RANDAXHE Benjamin 2214th June 2006

SeriesParallel

Cchan

DataPower Control

*j

Chips

jQ

I

RANDAXHE Benjamin 2314th June 2006

Cscr

QPSK Modulator

DPDCH 1

SCH

DPDCH 2

DPDCH x

PDSCH

PCCPCH

SCCPCH

PICH

AICH

CPICH

DPCCH

RANDAXHE Benjamin 2414th June 2006

Two speparated signals: Data Control

HPSK Modulation Channelisation

Channelisation

Data

Control

Scrambling

Modulator

*j

RANDAXHE Benjamin 2514th June 2006

QPSK HPSK

RANDAXHE Benjamin 2614th June 2006

UMTSOverview

Air interfaceGeneralityCodingPower

ModulationUMTS modulatorRAKE receiver

RANDAXHE Benjamin 2714th June 2006

Problems :Reflected RF Absorbed RF Diffraction

RANDAXHE Benjamin 2814th June 2006

With a reference channel, RAKE receiver is able to detect and to correct the corrupted signal

Rake #3

Rake #2

Original signal is found

Rake #1

CombinerData

correctedData

receivedData sent

Thank you

Presentationand memoir

http://users.skynet.be/bk331357/umts/

Question

http://users.skynet.be/bk331357/umts/

Thank you