3g cdma - wcdma and cdma2000 rodger e. ziemer ieee communications society distinguished lecturer...

3G CDMA - WCDMA and cdma2000

Rodger E. Ziemer

IEEE Communications Society

Distinguished Lecturer Program

May 28-June1, 2001 R. Z. Ziemer, Colorado Springs, CO

2

Rules for Efficient Multiple Access Three laws

Know the channelMinimize interference to othersMitigate interference received from others

Requirements of wireless multiple accessChannel measurementChannel control and modificationMultiple user channel isolation


3

Why CDMA? Higher capacity Improved performance in multipath by diversity Lower mobile transmit power = longer battery life

Power control Variable transmission rate with voice activity detection

Allows soft handoff Sectorization gain High peak data rates can be accommodated Combats other-user interference = lower reuse factors


4

What is Third Generation? [1] Flexible support of multiple services

Voice Messaging – email, fax, etc. Medium-rate multimedia – Internet access, educational High-rate multimedia – file transfer, video High-rate interactive multimedia – video telecon-ferencing,

telemedicine, etc.

Mobility: quasi-stationary to high-speed platforms Global roaming: ubiquitous, seamless coverage Evolution from second generation systems


5

W-CDMA Versus cdma2000 [2]Parameter W-CDMA cdma2000Carrier spacing 5 MHz 3.75 MHz

Chip rate 4.096 MHz 3.6864 MHz

Data modulation BPSK FW – QPSK; RV - BPSK

Spreading Complex (OQPSK) Complex (OQPSK)

Power control frequency 1500 Hz 800 Hz

Variable data rate implement. Variable SF; multicode Repet., puncturing, multicode

Frame duration 10 ms 20 ms (also 5, 30, 40)

Coding Turbo and convolutional Turbo and convolutional

Base stations synchronized? Asynchronous Synchronous

Base station acquisition/detect 3 step; slot, frame, code Time shifted PN correlation

Forward link pilot TDM dedicated pilot CDM common pilot

Antenna beam forming TDM dedicated pilot Auxiliary pilot


6

WCDMA Uplink Frame Structure [1]DPDCHI: data channel

Q: sync & control DPCCH

)6,,0( bits 2*10 k kN data

chips 2560 slotT

bits pilotNPilot: TFCI FBI TPC

TFCI = transmit format combination indicatorFBI = feedback informationTPC = transmit power control

DPDCH = dedicated physical data channelDPCCH = dedicated physical control channel

ms 667.0

slot 0 slot 1 slot i slot 14

radio frame = 10 ms


7

WCDMA Uplink Modulator Structure [1]

pulse shapefilter (SRC)


d

d

d

c

1,dc

)cos( tc

)sin( tc

2,dc

3,dc

cc

DPDCH1

DPDCH2

DPDCH3

DPCCH

I

Q

long,1c long,2c

+

+

+

-

+

+


8

Orthogonal Variable Spreading Factor Codes

00

0

000000000000

01

0011

0101

0110

00001111

00110011

00111100

01010101

01011010

01100110

01101001

Cd, i selected from this tree Notes:1) For fixed chip rate, desired information rate determines length of spreading sequence and therefore processing gain.2) When a specific code is used, no other code on the path from that code to the root and or on the subtree beneath that code may be used.3) All the codes at any depth into the tree are the set of Walsh Sequences.4) Code phase is synchronous with information symbols.5) FDD UL processing gain between 256 and 4 FDD DL processing gain between 512 and 4 TDD UL/DL processing gain between 16 and 16) Multicode used only for SF = 4


9

WCDMA Downlink Frame Structure [1]

DPDCH DPCCH

chips 2560 slotT

TFCI PilotTPC

ms 667.0

slot 0 slot 1 slot i slot 14

radio frame = 10 ms

DPDCHDPCCH

1 dataN 2 dataNData1 Data2

)7,,0( bits 2*10 22 kNN kdatadata


10

WCDMA Downlink Modulator Structure [1]

long,2c

tje

long C

long C


PrimarySync Code

SecondarySync Code

1 G

nG

PG

SG

sum

1,dc

ndc ,

PC

SC

dedicatedtraffic channels

primary &secondarycommon pilotchannels

primary &secondarycommoncontrolchannels

other channels

s/p

s/p


11

Transmit Diversity Strategy for Downlink


12

cdma2000 Uplink Frame Structure

CRCencodertail bits

Convolutionalor Turbo Coder

symbolrepetition

symbolpuncture

blockinterleaver

modulation symbol

C

channel bits

Bits/Frame1640 80 172350744151230486120

CRC bits668121616161616

tail bits888888888

Data Ratekbps1.52.74.89.619.238.476.8153.6307.2

CodeRate1/41/41/41/41/41/41/41/41/2

Repeats1684211111

Delete1 of 51 of 9nonenone none none none none none

Symbols153615361536153615363072 6144 12288 12288

Radio Configuration 3

C.S.0002-A-1 Fig 2.1.3.1.1.1-8


13

cdma2000 Uplink Modulator

C

C

C

A

B

d

d

d

c

)cos( tc

)sin( tcIlong,c

Qlong,c

+

+

+

+

+

_

sum

sum1 Dw

Cw

2 Sw

1 Sw

PrimaryTraffic

SecondaryTraffic 1

SecondaryTraffic 2

Control

Pilot

pulseshape

pulseshape


14

cdma2000 Downlink Frame Structure

Other similar tables in specification.

Bits/Frame2155 125 267552112822804584919220712

CRC bits681012161616161616

tail bits8888888888

Data Ratekbps1.83.67.214.428.857.6115.2230.4460.81036.8

CodeRate1/21/21/21/21/21/21/21/21/21/2

Repeats8421111111

Deletenonenonenonenone none none none nonenone2 of 18

Symbols57657657657611522304 4608 92161843236864

Radio Configuration 9

CRCencodertail bits

Convolutionalor Turbo Coder

symbolrepetition

symbolpuncture

blockinterleaver

modulation symbol

channel bits

W


15

cdma2000 1X DL Modulation Processing+

longcode

longcodemask

0 11 -1

channelgain

fwd pwrctrl gain po

wer

con

trol

sym

bol p

unc

ture

DE

MU

X

decimate pwr ctrlbit pos

I/Q scrambling bit extract

powercontrol

bits

puncturetiming800 Hz

W

YQ

YI

C.S.0002-A-1 Fig 3.1.3.1.1.1-18

modulationsymbol

rate


16

cdma2000 1X Downlink Modulation

I channelpilot PN

Q channelpilot PN

Walsh code

QOF code

IY

QY

pulseshape

pulseshape

+

+

+

-

)cos( tc

)sin( tc

otherchannels

otherchannels

pha

se

rota

te f

or Q

OF

QX

IX


17

cdma2000 3X DL Modulation Processing

+

longcode

longcodemask

0 11 -1

channelgain

fwd pwrctrl gain po

wer

con

trol

sym

bol p

unc

ture

DE

MU

X

decimate pwr ctrlbit pos

I/Q scrambling bit extract

powercontrol

bits

puncturetiming800 Hz

WYQ1

YI1

modulationsymbol

rate

YQ2

YI2

YQ3

YI3


18

cdma2000 3X Downlink Modulation

same as below

same as above

outputcarrier 1

outputcarrier 2

outputcarrier 3

YQ1

YI1

YQ2

YI2

YQ3

YI3


19

cdma2000 vs WCDMA Chip rate Coherent Pilot Channels Transmit Diversity Underlying Network Single Carrier versus Multicarrier Spreading Cell Site Synchronization


20

References[1] R. L. Peterson, “Third Generation Personal Communications: Physical Layer

Status,” Presentation at Clemson University, Feb. 1, 2001

[2] Manjit Singh and Manoneet Singh, “3G Wireless with Respect to IMT-2000 and Beyond,” Telecom 99

[3] Harri Holma and Antti Toskala, WCDMA for UMTS: Radio Access for Third Generation Mobile Communications, New York: Wiley, 2000

[4] “CDMA Evolution from IS-95, IS-2000, to 1XTREME,” Technology Transfer Training Class, Motorola, Inc., July 2000

[5] R. Ziemer and R. Peterson, Introduction to Digital Communications, Upper Saddle River, NJ: Prentice Hall, Chapter 10, 2001


21

WCDMA: More Information? http://www.3gpp.org

21.101 guide to all other documents 25.XXX series radio access network (RAN)

25.211 frame structure etc. 25.212 channel coding etc. 25.213 spreading and modulation 25.214 physical layer procedures (tx diversity, etc.) 25.321 medium access control (MAC) 25.322 radio link control (RLC)

26.XXX series voice coding


22

GSM/GPRS/EDGE: More Information? http://www.3gpp.org

multiple access, logical channels, etc05.0245.002

general description05.0145.001

modulation05.0445.004

channel coding05.0345.003

RLC/MAC04.6044.060

link adaptation05.0945.009

radio link control05.0845.008

radio transmission and channel models05.0545.005

descriptionETSI3GPP


23

cdma2000: More Information? http://www.3gpp2.org

Technical Specification Group C cdma2000C.S0002-A-1 Physical Layer StandardC.S0003-A-1 Medium Access Control (MAC)C.S0004-A-1 Signaling Link Access Control C.S00024 1XEV-DO (high speed packet)C.S0005 Upper Layer Signaling (L3)


24

3G Information Sources Third Generation Partnership Projects

http://www.3gpp.org http://www.3gpp2.org

CDMA Development Group (CDG) http://www.cdg.org

International Mobile Telecommunications for the year 2000 http://www.tiaonline.org/standards/sfg/imt2k/

Japan ARIB IMT-2000 proposal http://www.arib.or.jp/IMT-2000/ARIB/Document/

3g cdma - wcdma and cdma2000 rodger e. ziemer ieee communications society distinguished lecturer...

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