cdma2000 fundamentals agilent

7/27/2019 Cdma2000 Fundamentals Agilent

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CDMA Fundamentals


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Agenda

CDMA introduction

CDMA makes use of Diversity

Power control

CDMA Forward Link

CDMA Reverse Link

CDMA call processing CDMA Measurement


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Cellular Access Methods

Power Time

FrequencyFDMA

PowerTime

Frequency

Power

Time

Frequency

TDMA

CDMA


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User #3

Frequency Domain

User #2

User #1

Synch

Paging

Pilot

1.2288 MHzfreq

Code Domain

0 1 2 3 4 5 6 7 8 9 32 40 63

User

1

User

3

User

2

Walsh Code

Pilot Paging Synch

Code Domain Power (cdma2000/IS-95)

The CDMA Concept


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CDMA is Also Full Duplex

US Cellular Channel 384Amplitude

Frequency

AMPS

CDMAFrequency

Amplitude

Reverse Link

Reverse Link

Forward Link

Forward Link

45 MHz

45 MHz

836.52 MHz

836.52 MHz 881.52 MHz

881.52 MHz


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Code Division MultipleAccess

What is CDMA ?

Spread spectrum technique

Multiple users share the same frequency in one cell

Same frequency in all the cells Operates under presence of interference

Takes advantage of multipath

Capacity is soft


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Cellular Frequency Reuse Patterns

3

6

CDMA ReuseFDMA Reuse

11

1

1

1

1

11

1

62

2

1

4

5

7


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The CDMA Concept

Baseband

Data

Encoding &

Interleaving

Walsh Code

Spreading

Walsh Code

Correlator

Baseband

Data

Decode & De-

Interleaving

0 0fcfc

fcfcfcfc

10 Khz BW 1.23 Mhz BW 10 Khz BW1.23 Mhz BW

1.23 Mhz BW1.23 Mhz BWSpurious Signals-113 dBm/1.23 Mhz

CDMA

Transmitter

CDMA

Receiver

9.6 kbps 19.2 kbps 1228.8 kbps 9.6 kbps19.2 kbps1228.8 kbps

Background Noise External Interference Other Cell Interference Other User Noise

Interference Sources


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z Multiple user data can be spread by using combinations ofthis PN code

Direct Sequence Spread Spectrum

Baseband data multiplied by a Pseudo Random Noise (PN)Code, which is a sequence of chips valued -1 & +1 or 0 & 1

PN code is a noise-like code with certain properties (ex:orthogonal)


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Direct sequence spreadspectrum signal is generated

by multiplying narrowbanduser data with a well-defined

wideband pseudo-random

sequence.

Recovering the narrowbanduser data is achieved by

multiplying the received

signal by an identical,

accurately timed pseudo-random sequence.


Power SpectralDensity

Freq

Direct sequencespread signal

Narrowband userdata


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Source InformationBits

I-Q Modulator

CarrierCode Generator BitStream

TransmitDSSS Signal

Block diagram of a Direct Sequence SpreadSpectrum Transmitter

Bits toI-Q


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Received

DSSSsignal

CodeSynchronization Code Generator

Demodulator

Carrier

Data

Block diagram of a Direct Sequence Spread Spectrum Receiver


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What is Correlation ?

Is a Measure of HowWell a Given Signal

Matches a Desired

Code

The Desired Code isCompared to the

Given Signal at

Various Test times

Received Signal

Time

Correlation = 1

Correlation = 0

Correlation = 0

Correlation = 0


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Auto-Correlation

Is a Comparison of a Signal

Against Itself

Good Pseudo-RandomPatterns Have:

Strong Correlation at Zero Time

Offset

Weak Correlation at Other

Time Offsets

Pseudo-Random Sequence

Auto-Correlation Versus Time Offset

1

0

1

300 5 10 15 20 25

0 10 205 15 25 30

0

Chip Offset


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Analog

Analog

CDMA Paradigm Shift

Multiple Users on One Frequency99 Analog/TDMA Try to Prevent Mu lt ip le UsersAnalog/TDMA Try to Prevent Mu lt ip le Users

InterfaceInterface

Channel is Defined by Code99 Analog Systems Def ined Channels byAnalog Systems Def ined Channels by

FrequencyFrequency

Traditional FDMA/TDMA are capacity-

limited99 Given N t imeslots per frame and KGiven N t imeslots per frame and Kfrequency channels , max imum n umber off requency channels , max imum n umber of

users is KN;users is KN;

99 To increase the number of u sers in theTo increase the num ber of us ers in the

system , frequency reuse is usedsystem , frequency reuse is us ed

Capacity Limit is Soft99 Al low s Degradin g Voice Quali ty toAl low s Degradin g Voice Qual i ty to

Temporari ly Increase CapacityTempo rari ly Inc rease Capacity

99 Reduce Surrounding Cel l Capaci ty toReduce Surrou nd ing Cel l Capaci ty to

Increase a CellIncrease a Cells Capacitys Capacity

CD

MA


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CDMA Capacity Gains

ProcessingProcessingGainGain

AMPS = 1.5 MHz / 30 kHz = 50 Channels

Capacity = 50 Channels / 7 ( 1/7 Frequency Reuse )

AMPS = 7 Calls ( Usin g 1.5 MHz BW )

CDMA = 42 Calls ( Usin g 1.5 MHz BW )

(1,230,000) (1) (1)CDMA = ____________ X _____ X _____ X (0.67)(9,600) (5.01) (.40)

Capacity = _____________ X _____ X ____ X (Fr)(Data Rate) (S/N) (Vaf)

(Chan BW) (1) (1)


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CDMA makes use of Diversity

Spatial Diversity

Making Use of Differences in Position

Frequency Diversity Making Use of Differences in Frequency

Time Diversity

Making Use of Differences in Time


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CDMA Spatial Diversity

Diversity Reception:

Multiple Antennas at Base Station

99Each A ntenna is Affected byEach A ntenna is Affected b yMul t ipathMul t ipathDifferently Due to TheirDifferently Due to TheirDi f ferent L ocat ionDif ferent L ocat ion

99Al low s Select ion o f the Signal Least A ffected byAl low s Select ion of the Signal Least Affected byMul t ipathMul t ipath

FadingFading

If Diversity Antennas are Good, Why Not Use Base Stationsas a Diversity Network?

Soft Handoff


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Spatial Diversity During Soft Handoff

MTSO

Base Station 1

Land Link

Vocoder /

Selector

Base Station 2


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CDMA Time Diversity

Rake Receiver to Find and DemodulateMultipath Signals

Data is Interleaved

Spreads Adjacent Data in time to Improve

Error Correction Efficiency

Convolutional EncodingAdds Error Correction and Detection

Viterbi Decoding

Most Likely Path Decoder forConvolutionaly Encoded Data


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Why Interleaving Works

1 2 3 4

5 6 7 89 10 11 12

13 14 15 16

1 5 9 13

3 7 11 15

4 8 12 16

1 2 3 4

9 10 11 12

13 14 15 16

5 6 7 8

Original Data Frame

Interleaved Data Frame

Errors/Time

TX1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Errors/Time

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

RX

Errors/Time

TX

1 5 9 13 2 6 10 14 3 7 11 15 4 8 12 16

Errors/Time

RX

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

2 6 10 14


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The Rake Receiver

Amplitude

Frequency

Time


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Rake Receiver Design

T0 T1 T4T3T2

W0 W1 W2 W3 W4

Antenna

Output

Delay

Taps

Tap

Weights

+


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Synchronization

All Direct Sequence, SpreadSpectrum Systems Should be

Accurately Synchronized for

Efficient searching

Finding the Desired CodeBecomes Difficult without

Synchronization


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Power Control

Near-end Far-end Problem

- 60dBm

- 30dBm

A

B

At the BS receiver,

SNR for A reception = 30 dB, certified

SNR for B reception = -30 dB, not certified


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z Acceptable SNR is at least 7 dB

z For B, the signal needs 37 dB gain to meet the condition

z What if we increase the processing gain from 21 dB to 37

dB?

Pgain = 10 log ( W / R )

R is fixed at 9600 bps, W can be increased

Is there another way to improve S/N?

In this case, W = 48 MHz not practical

Power Control


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z In this case, B is the Signal and A is the Noise

z Both A and B are transmitting at constant power

z Since A is near, it can be asked to transmit at low power

z

Since B is far, it can increase the powerThis is Power Control !This is Power Control !

z Base Station will change power levels based on

the Path loss.

z Base Station will also command Mobile to

increase or decrease power levels.

Power Control


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Maximum System Capacity is Achieved if:

9All Mobiles are Power Controlled to the Minimum

Power for Acceptable Signal Quality

9As a Result, all Mobiles are Received at About

Equal Power at the Base Station Independent of

Their Location

Two Types of Control

Open Loop Power Control

Closed Loop Power Control

Open & Closed Loop Power Control areAlways Both ActiveAlways Both Active

Reverse Link Power Control


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Open Loop Power Control

Assumes Loss is Similar on Forward and ReversePaths

Receive Power + Transmit Power = -73(-76dB forPCS Band

All Powers in dBm

Example:

For a Received Power of -85 dBm Transm it Power = (Transm it Power = (--73)73)--((--85)85)

Transm it Power = +12Transm it Power = +12dBmdBm

Provides an Estimate of Reverse TX Power for GivenPropagation Conditions


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Directed by Base Station

Updated Every 1.25 msec

Commands Mobile to Change TXPower in +/- 1 dB Step Size

Fine Tunes Open Loop PowerEstimate

Power Control Bits are Puncturedover the Encoded Voice Data

Puncture Period is Two 19.2 kbps

Symbol Periods = 104.2 usec

Closed Loop Power Control


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CDMA Variable Rate Speech Coder

DSP Analyzes 20 Millisecond Blocks of Speech for Activity

Selects Encoding Rate Based on Activity:

a High Activity Full Data Rate Encoding (9600 bps)a Some Activity Half Data Rate Encoding (4800 bps)

a Low Activity Quarter Data Rate Encoding (2400 bps)

a No Activity 1/8 Data Rate Encoding (1200 bps)

How Does This Improve Capacity? Mobile Transmits in Bursts of 1.25 ms

System Capacity Increases by 1/Voice Activity Factor


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Mobile Power Bursting

Each Frame is Dividedinto 16 Power Control

Groups

Each Power ControlGroup Contains 1536

Chips (represents 12

encoded voice bits)

Average Power isLowered 3 dB for Each

Lower Data Rate

CDMA Frame = 20 ms Full Rate

Half Rate

Quarter Rate

Eighth Rate


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The CDMA2000 evolution path is flexible

and future-proof

Voice

Data up to

14.4 kbps

Voice

Data up to

115 kbps

2x increases in voice capacity

Up to 307 kbps* packet data

on a single (1.25 MHz) carrier

First 3G system for any

technology worldwide

Optimized, very high-speed

data (Phase 1)

Up to 2.4 Mbps* packet data

on a single (1.25 MHz) carrier

Integrated voice and data

(Phase 2); up to 4.8 Mbps

*downlink

From CDG


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CDMA Protocol Stacks

IS -95 Rev 0Original System-never actually deployed

ARIB T53Japan CDMA

System Cellular

Protocol

IS -95 Rev ABackwards compatible with IS-95. First Deployed Protocol

TBS- 74Cellular Protocol that adds 14400 Channel Support

J-STD-008Not Backwards Compatible, PCS only Protocol

EIA/TIA-95 Rev BCombines TSB-74 & J-STD-008 for a Universal Protocol

EIA/TIA/IS-2000 Rev 0First release of IS-2000 standard (add QPCH)

EIA/TIA/IS-2000 Rev AAdd BCH,CCCH,CACHnew channel

EIA/TIA/IS-2000 Rev BAdd new functionality and support

EIA/TIA/IS-2000 Rev C(1x EV-DV)Segment channel between Voice and Data

EIA/TIA/IS-856(1x EV-DO)Optimized for packet data.


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The architecture for CDMA2000

IS634

PSDN

MSC

HLR/AUCHLR/AUC

Laptops with

Cell Phones

Cell

Phones

Smartphones

and PDAs

BSCAAAAAA

ServerServer

PSTN

Internet

IWF

IP Router

Core

Elements

Core

Elements

From CDG


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cdma2000 Key Standards

EIA/TIA/IS-2000 rev. 0 Interoperability Standard forcdma2000 Spread Spectrum Systems

Defines channel coding, call processing procedures, protocoland other mobile / base procedures and RF requirements to

ensure interoperability of equipment from multiple vendors

Defines how entire system works together in extreme detail

Revision 0 was first release of standard.

Revision A adds enhanced channels for paging, call set-up and

call control.

Revision B enhanced from the cdma2000 Release A

specifications


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TIA/ EIA-95-B IS-2000 IS-2000-A

F-Pilot F-Pilot F-Pilot

F-Sync F-Sync F-Sync

F-PCH F-PCH F-BCCHF-CCCH

F-QPCH optional F-QPCH optional

F-CACH

F-CPCCH

Forward

Channels

F-Traffic

F-FCH

F-SCH

F-DCCH optional

F-FCH

F-SCH

F-DCCH optional

N/ A R-Pilot R-Pilot

R-ACH R-ACH R-EACHorR-CCCHReverse

ChannelsR-Traffic

R-FCH

R-SCH

R-DCCH optional

R-FCH

R-SCH

R-DCCH optional

cdma2000 Standards Overview - IS-2000

Release 0 versus Revision A


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Benefits of cdma2000

Improved Performance and Capacity:

About 2X Voice Capacity of TIA/EIA-95-B

Handles a Wide Range of Data Rates:99Voice and Low Speed Data wh i le Driv ingVoice and Low Speed Data whi le Driv ing

99Up to 384 kbps Packet or Circui t Data wh i le Movin gUp to 384 kbps Packet or Circui t Data wh i le Moving

99Up to 2 Mbps Data Rates for Fixed Ins tal lat ion sUp to 2 Mbps Data Rates fo r Fixed Ins tal lat ion s

Meets All IMT-2000 Requirements Easy Upgrade for Service Providers Who Currently Operate

TIA/EIA-95 Systems


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cdm

a

2000

Performance Enhancements

Reverse Link Pilot for Each Mobile

True QPSK Modulation

Continuous Reverse Link Waveform Improved Convolutional Encoding for 14.4

kbps Voice Channels

Fast Forward & Reverse Link Power Control

Supports Auxiliary Pilots for Beam Forming

Forward Link Transmit Diversity - OTD,

STS, Multi-Antenna


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Terms and Definitions

Chip

99 Is the period o f a data bit at the final spreadin g rateIs the period o f a data bit at the final spreadin g rate

SR - Spreading Rate99Defines the fin al sp readin g rate in terms o f 1.2288 Mcps(SR1).Defines the fin al spreadin g rate in terms of 1.2288 Mcps (SR1).

So a 3.6864So a 3.6864McpsMcpssystem is cal led a SR3 system.system is cal led a SR3 system.

RC - Radio Configuration

99Defines the physical channel con f igurat ion based upon a baseDef ines the physical channel conf ig urat ion based upon a basechannel data rate.channel data rate.

99RCsRCscontain rates derived from their base rate. For examp le,contain rates derived from their base rate. For examp le,

RC3 is b ased on 9.6 kbps and inclu des 1.5, 2.7, 4.8, 9.6, 19.2,RC3 is based on 9.6 kbps and inclu des 1.5, 2.7, 4.8, 9.6, 19.2,

38.4, 76.8, 153.6, and 307.200 kb ps .38.4, 76.8, 153.6, and 307.200 kb ps.

99RCsRCsare cou pled to speci f ic Spreading Ratesare cou pled to speci f ic Spreading Rates

IS 2000 SR1 ( k 1 RTT)


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IS-2000 SR1 (aka 1xRTT)

Is an Improved TIA/EIA-95-B Narrowband System

Occupies the Same 1.23 MHz Bandwidth as TIA/EIA-95-B

Forward Link:99Add s Fast Power Contro lAdds Fast Power Contro l

99Quick Paging Channel to Improve Standby TimeQuick Paging Channel to Improve Standby Time

99Uses QPSK Modu lat ion Rather than Dual BPSK to:Uses QPSK Modulat ion Rather than Dual BPSK to:

Use 3/8 Rate Convolutional Encoder instead of 3/4 for 14.4 Service(improves error correction)

128 Walsh Codes to Handle More Soft Handoffs for 9.6 service

Reverse Link:

99Uses Pi lot Aided BPSK to A l low Coherent Demodulat ionUses Pi lot Aided BPSK to A l low Coherent Demodulat ion

99Uses 1/4 RateUses 1/4 RateConvolut ionalConvolut ionalEnco der Instead o f 1/2 or 1/3Encoder Instead o f 1/2 or 1/3

99Uses HPSK Spreadin gUses HPSK Spreading

Doubles System Voice Capacity

SR1 F d R di C fi ti


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SR1 Forward Radio Configurations

Radio Configuration 1 - Required

99Backwards compat ible mode with TIA/EIABackwards com pat ible mode with TIA/EIA --9595--BB

99Based on 9,600 bp s Traff ic(RS1)Based on 9,600 bp s Traff ic(RS1)

Radio Configuration 2

99Backwards compat ible mode with TIA/EIABackwards com pat ible mode with TIA/EIA --9595--BB

99Based on 14,400 bp s Traff ic(RS2)Based on 14,400 bps Traff ic(RS2)

Radio Configurations 3, 4, and 599Al l use new cdm a2000 cod ing fo r imp roved capaci tyAl l use new cdma2000 cod ing fo r impro ved capaci ty

99RC3 is based on 9,600 bps and goes up to 153,600 bpsRC3 is based on 9,600 bps and goes up to 153,600 bps



SR1 F d Ch l


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SR1 Forward Channels

F-Pilot (Using TIA/EIA-95-B Coding)

F-Sync (Using TIA/EIA-95-B Coding)

Up to 7 F-Paging (Using TIA/EIA-95-B Coding) IS-2000 Rev.0

0 to 3 F-QPCH (Quick Paging Channel)

IS-2000 Rev.A/B 0 or 8 F-BCH (Broadcast Channel) 0 to 4 F-CPCCH (Common Power Control Channel)

0 to 7 F-CACH (Common Assignment Channel)

0 to 7 F-CCCH (Common Control Channels)

Many F-Traffic Channels, Each Consisting of:99 0 or 1 F0 or 1 F--DCCH (Dedicated Con trol Channels)DCCH (Dedicated Cont rol Chann els)

99 1 F1 F--FCH (Fundamental Chann el)FCH (Fundamental Channel)

99 0 to 7 F0 to 7 F--SCCH (Supplemental Code Channels for RC1 & RC2)SCCH (Supplemental Code Channels for RC1 & RC2)

99 0 to 2 F0 to 2 F--SCH (Supplemental Chann el for RC3, 4, 5)SCH (Supplemental Chann el for RC3, 4, 5)

B St ti V i bl R t V d


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Base Station Variable Rate Vocoder

Base Stations Do Not Pulse TX Channels

How Does the Base Station Handle Variable

Rate Vocoding? Repeats Data Bits When Transmitting at

Reduced Rates

Repeating Data Adds 3 dB Coding Gain

Lowers the TX Power 3dB for Each Lower

Rate

Forward Link Traffic Channel Physical Layer


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Walsh CodeGenerator

Forward Link Traffic Channel Physical Layer

(RC1,RC2)

1/2

Rate

3/4

Rate

P.C.

Mux

Vocoded

SpeechData

20 msec

blocks

ConvolutionalEncoder

InterleaverLong Code

Scrambling

Power

ControlPuncturing

800 bps Walsh

Coder9.6

kbps

14.4

kbps

19.2kbps

19.2

kbps

Long Code

19.2

kbps

19.2

kbps

19.2

kbps

19.2kbps

1.2288 Mbps

1.2288 Mbps

1.2288

Mbps

1.2288

Mbps

Short Code Scrambler

800

bps

FIR

FIR

I

Q

I Short Code

Q Short Code

Forward FCH Physical Layer


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Forward FCH Physical Layer

RC3 (9.6 kbps)

OptionalCan be Carried by F-DCCH

8.6 kbps

1228.8 kbps

Long Code

Decimator

Interleaver

38.4 ksps

1/4 Rate Conv.

Encoder

38.4 ksps

9.6 kbps

Long Code

Generator

38.4 kbps

Power

Control

Puncture

Walsh 64

Generator

1228.8 kcps

1228.8 kcps

1228.8 kbps

1228.8kbps

Q

I

S -P

800 bps

PCUser Long

Code Mask

Q

I

PC

Dec

1228.8 kcps

Q Short Code

I

Q

1228.8 kcps

Complex

Scrambling

Q

I

FIR

FIRI Short Code

Orthogonal

Spreading

1228.8 kcps

1228.8 kcps+

+

+

-

38.4

ksps

19.2 ksps

19.2 ksps

P.C. Bits

Decimate by

Walsh Length/2

Gain

Gain

Puncture

Timing

Full Rate

Data BitsAdd CRC and

Tail Bits

800 bps

CDMA Vocoders


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CDMA Vocoders

Vocoders Convert Voice to/from Analog Using DataCompression

There are Three CDMA Vocoders: IS-96A Variable Rate (8 kbps maximum)

CDG Variable Rate (13 kbps maximum)

EVRC Variable Rate (improved 8 kbps)

Each has Different Voice Quality: IS-96A - moderate quality

EVRC - near toll quality

CDG - toll quality

CDMA Frame Formats


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15

24 bits in a ms frame

39

79

171 266

124

54

201200 bps

Frame8

Mixed Mode BitInformation Bits

1-bit

Reserved

8

8

88

12 12 8

10 8

6

88

8

Mixed Mode Bit

Mixed Mode Bit

Mixed Mode Bit

Information Bits

Information Bits

Information Bits

2400 bps

Frame

9600 bps

Frame

4800 bps

Frame




1800 bps

Frame

3600 bps

Frame

7200 bps

Frame

14400 bps

Frame





1-bit

Reserved

1-bit

Reserved

1-bit

Reserved

Mixed

Mode Bit

Mixed

Mode Bit

Mixed

Mode Bit

Mixed

Mode Bit

Encoder

Tail Bits

CRC

CRC

Encoder

Tail Bits

Encoder

Tail Bits

Encoder

Tail Bits

Information Bits

Information Bits

Information Bits

Information BitsEncoder

Tail Bits

Encoder

Tail Bits

Encoder

Tail Bits

Encoder

Tail Bits

CRC

CRC CRC

CRC

CDMA Frame Formats

Forward Error Protection


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Forward Error Protection

Uses Half-Rate Convolutional Encoder

Outputs Two Bits of Encoded Data for Every Input Bit

Data Out

9600 bps

Data Out

9600 bps

D DDDD D D D

+

+

Data In

9600

bps

zzzz z zz

14 4 Traffic Channel Forward Link


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14.4 Traffic Channel Forward Link

Modifications Replaces 8 kbps Vocoder with a

13 kbps Vocoder(both Variable

Rate)

Effects:

Provides Toll Quality Speech

Uses a 3/4 Rate Encoder

Reduces Processing Gain 1.76 dB

Results in Reduced Capacity or

Smaller Cell Sizes

3/4rate

Vocoded

Speech

Data


20 msec

blocks

14.4

kbps

19.2

kbps

Interleaver


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384 symbols are sequentially written in an input array

Interleaved symbols are then read from the output array

19.2 ksps9.6 ksps4.8 ksps2.4 ksps

SymbolRepetition

19.2 ksps

384 Symbols

20 ms

Block

InterleaverInput

Array /output

Array

16 x 24 Array

Interleaved

Output

16

24

Interleaver

Process of permuting a sequence of symbols to achieve time

diversity

CDMA uses block interleaving with 20 ms blocks

CDMA System Time


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CDMA System Time

How Does CDMA Achieve

Synchronization for Efficient

searching?

Use GPS Satellite System

Base Stations Use GPS Time

via Satellite Receivers as a

Common Time Reference

GPS Clock Drives the LongCode Generator

112

2

3

45

67

8

9

1011

Long Code Generation


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Modulo-2 Addition

Long Code Output

Long Code Generator

1

User Assigned

Long Code Mask42 bits

24 342 41 5




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Modulo-2 Addition

Long Code Output

34 12

User Assigned

Long Code Mask

42 bits4142 5

Long Code Generator(Driven by System Time)

1100011000 Permuted ESN

41 32 31 0

Long Code Mask

Long Code Scrambling


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g g

Users Long Code Mask is

Applied to the Long Code

Masked Long Code is

Decimated Down to 19.2 kbps

Decimated Long Code is

XORed with Voice Data Bits

Scrambles the Data to Provide

Voice Security

Encoded

Voice Data

Long Code

Generator

Long Code

Decimator

XOR

1.2288 Mbps

19.2 kbps

19.2 kbps

19.2 kbps

Closed Loop Power Control Puncturing


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19.2 kbps

p g

Long Code is Decimated

Down to 800 bps

Decimated Long Code

Controls the Puncture

Location

Power Control Bits Replace

Voice Data Voice Data is Recovered by

the Mobiles Viterbi Decoder

Long Code

Scrambled

Voice Data

Long CodeDecimated

Data

Closed Loop

Power

Control Bits

P. C.

Mux

Long Code

Decimator

800 bps

800 bps

19.2 kbps

19.2 kbps

Power Control Bit Puncturing


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g

z 19.2 ksps: 384 symbols / 20ms frame

z Each 20ms frame is divided into 16 power control

group (1.25 ms each)

z 24 modulation symbols in each power control group

Long Code DecimatedData

Decimator19.2 ksps

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

4 symbols = 16 combinations

20ms

1.25ms

If [20,21,22,23]=[1,1,0,1],then puncture bit 11,12

SR1, RC4 (152.4 kbps) F-SCH


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Payload

Data Bits

1228.8 kbps

Long Code

Decimator

Interleaver

1/2 Rate

Convolutional

Encoder

307.2 ksps

Channel

Coder

Add CRC and

Tail Bits

153.6 kbps

Long Code

Generator

User Long

Code Mask

Decimate by

Walsh Length/2

307.2 ksps

307.2 ksps

307.2 ksps

GainWalsh 8

Generator

1228.8 kcps

1228.8 kcps

1228.8 kbps

1228.8kbps

Q

I

S -P

Q

I

1228.8 kcps

Q Short Code

I

Q

1228.8 kcps

Complex

Scrambling

FIR

FIRI Short Code

Orthogonal

Spreading

1228.8 kcps

1228.8 kcps

+

+

+

-

153.6 ksps

153.6 ksps

152.4 kbps

( p )

Walsh Codes


61/120

61

W=0 0

0 1

W = 0

0 0 0 0

0 1 0 1

0 0 1 10 1 1 0

W=

1

2

4

=nn

nn

n

WW

WWW2

Checking for Orthogonality


62/120

62

2 Match - 2 dont = 0

W =4

0 0 0 00 1 0 1

0 0 1 1

0 1 1 0

0 0 0 00 0 1 1

Y Y N N

Cross

Correlation= Nagreements

- Ndisagreements

N total_number_of_digits

Effects of Using Variable Length Walsh Codesf S di


63/120

63

SF=16SF=2 SF=4 SF=8

1 1 1 1 1 1 1 1

1 1 1 1 -1 -1 -1 -1

1 1 -1 -1

1 1 1 1

1 1

1 -1

1 -1 1 -1

1 -1 -1 1

1

1 -1 1 -1 1 -1 1 -1

1 -1 1 -1 -1 1 -1 1

1 -1 -1 1 1 -1 -1 1

1 -1 -1 1 -1 1 1 -1

1 1 -1 -1 -1 -1 1 1

1 1 -1 -1 1 1 -1 -1

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 -1 -1 -1 -1 -1 -1 -1 -1

1 1 1 1 -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -11 1 1 1 -1 -1 -1 -1 -1 -1 -1 -1 1 1 1 1

1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1

1 1 -1 -1 1 1 -1 -1 -1 -1 1 1 -1 -1 1 1

1 1 -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1 1 1

1 1 -1 -1 -1 -1 1 1 -1 -1 1 1 1 1 -1 -1

1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1

1 -1 1 -1 1 -1 1 -1 -1 1 -1 1 -1 1 -1 1

1 -1 1 -1 -1 1 -1 1 1 -1 1 -1 -1 1 -1 1

1 -1 1 -1 -1 1 -1 1 -1 1 -1 1 1 -1 1 -1

1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1

1 -1 -1 1 1 -1 -1 1 -1 1 1 -1 -1 1 1 -1

1 -1 -1 1 -1 1 1 -1 1 -1 -1 1 -1 1 1 -1

1 -1 -1 1 -1 1 1 -1 -1 1 1 -1 1 -1 -1 1

for Spreading

Using Shorter

Walsh Codes

Precludes Using

all Longer CodesDerived from the

Original

Shorter Codes on

a Branch mapinto Longer

Codes

Walsh Code Spreading


64/120

64

Encoded

Voice Data

Walsh Code

Generator

19.2 kbps

1.2288 Mbps

1.2288 Mbps

What is the

Spread ing Rate

Inc rease ?

Why Spread Again with the Short Sequence


65/120

65

Provides a Cover to Hide the

64 Walsh Codes

Each Base Station is Assigned

a Time Offset in its ShortSequences

Time Offsets Allow Mobiles to

Distinguish Between Adjacent

Cells Also Allows Reuse of All Walsh

Codes in Each Cell

Walsh Coded

Data at1.2288 Mbps

1.2288 Mbps

1.2288 Mbps I Channel ShortSequence Code

Generator

Q Channel Short

Sequence CodeGenerator

To I/Q

Modulator

Multi-Layer Code Assignment Short Code


66/120

66

Walsh Code layer (spreading code)

Full codeset per cell

W64,1

W64,2

W64,0

Cells A/Sector A

W64,1

W64,2

W64,0

Cells B/Sector B

PN 0

PN 1

Convolutional

Encoder

Long code

Walsh Code

CDMA as an OnionCDMA as an Onion

Short Code (PN) Generation


67/120

67

z PN sequence codes are generated using 15-bit shift

registers

z PN sequence pattern repeats every 26.666 ms

z 75 PN sequences repetition occur every 2 seconds

z On every even second clock, MS will get PN sequence

initial state

Jan 6, 1980 00:00:00

1, 0, 0, 0.............. 0R1,R2,R3,R4..........R15

( initial state of 15 registers )

PN Code Combinations: 215 = 32768

Clock Rate = 1.2288 McpsReturn of Initial State = 26.666 ms

32768

32768

1

274

7532

768

2 sec26.666ms

PN Offsets


68/120

68

Each BS scrambles PN sequence with data by sometime offset

Time offsets are in intervals of 64 clock chips (52.08us) from even second clock

512 unique offsets arecreated (32768/64 = 512)

Each BS is allotted

an offset for PNsequence scrambling

PN 0

PN 120

PN 237

PN 511

PN 489

Short Code Correlation


69/120

69

Short Codes are Designed to

Have:

Strong Auto-Correlation at Zero

Time Offset

Weak Auto-Correlation at Other

Offsets

Good Auto-Correlation in Very

Poor Signal-to-Noise RatioEnvironments

Allows Fast Acquisition in Real

World Environment

Auto-Correlation Versus

Time Offset With 17 dB Noise Added

0 10 205 15 25 30

Chip Offset

Forward Link Channel Format


70/120

70

Convert to I/Q

& PN

Spreading

FIR LP Filter &

D/A Conversion

I Data

Q Data

1228.8 kbps

Walsh Code 0

Pilot Channel All 0s

Convert to I/Q

& PN

Spreading

FIR LP Filter &

D/A Conversion

I Data

Q Data

1228.8 kbps

Walsh Code 32

Sync Channel 4.8 kbps

Convert to I/Q

& PN

Spreading

FIR LP Filter &

D/A Conversion

I Data

Q Data

1228.8 kbps

Walsh Codes 1 to 7

Paging Channels1 up to 7 Channels

19.2 kbps

Convert to I/Q

& PN

Spreading

FIR LP Filter &

D/A Conversion

I Data

Q Data

1228.8 kbps

Walsh Codes 8-31,33-63

Traffic Channels1 up to 55 Channels

19.2 kbps

I

Q

Walsh Coding Example


71/120

71

W2=0 0 -User A

0 1 -User B

-1

-2

+1+2

-1

+1Channel A

Walsh Encoded

Voice Data

+1

-1

Channel A

Voice Data

For a 1 Input

Use Code 11

+1

-1

For a 0 Input

Use Code 00

User A User B

For a 0 Input

Use Code 01

For a 1 Input

Use Code 10

Channel B

Voice Data

Channel B

Walsh Encoded

Voice Data

Sum of A & B

Walsh Encoded

Data Streams

0 0

1 1

0 0 1 1 0 0 0 0

+1

-1

+1

-1

0 1

1 0

-1

+1

1 0 0 1 0 1 1 0

+0

+1

1 0 0 1

+1

0

1 0 0 1

Walsh Decoding Example


72/120

72

Correlation Coefficient

fi

(t) r fj

(t) dtzi j

=1

T

+1

01 0 0 1

+1

-1

+2

-2

Original User B Voice Data

User A & B Walsh Data

Multiply Summed Data with Desired Walsh Code

+1

01 0 0 1

+1

-1

+2

-2

Original User A Voice Data

User A & B Walsh Data


+1

-1

+2

-2

X

+1

-1 1 1

+1

-1

+2

-2 -1+1

-1

+2

-2

+1

-11 0 1

+1

-1

+2

-2

= = = =+

0T

What if Walsh Codes are Not Time Aligned ?


73/120

73

Channel B

Walsh

EncodedVoice Data -1

+1

1 0 0 1 0 1 1 0-1

+1Channel A

Walsh

EncodedVoice Data

0 0 1 1 0 0 0 0

-1

-2

+1Sum of A & B

Walsh EncodedData Streams

Original Data Was

0 (-1), We Have

Interference Now!


+1

-1

+2

-2

+1

-11 1

+1

-1

+2

-2

-0.75

Original Time Delayed

+

X = =

Pilot Channel Physical Layer


74/120

74

Walsh

Modulator

1.2288 Mbps

1.2288 Mbps

1.228

8

Mbps

1.228

8Mbps


FIR

FIR

I

Q

Walsh Code

Generator Q Short Code

I Short Code

All 0

Inputs

19.2

kbps

WalshCode 0

Uses Walsh Code 0:

All 64 bits are 0

All Data into WalshModulator is 0

Output of WalshModulator is therefore all

0s Pilot Channel is just the

Short Codes

Sync Channel Physical Layer


75/120

75

1/2

Rate2x

ConvolutionalEncoder Interleaver

Walsh

32

Coder

1.2

kbps

2.4

kbps

4.8

kbps

1.2288 Mbps

1.2288 Mbps

1.2288

Mbps

1.2288

Mbps


FIR

FIR

I

Q

Sync

Channel

Message

Data

Symbol

Repetition

4.8

kbps

Walsh CodeGenerator Q Short Code

I Short Code

Paging Channel Physical Layer


76/120

76

Paging Channel

Long Code

1/2

Rate


Interleaver

4.8kbps 9.6kbps 19.2kbps

Paging

Channel

Message

Data

2x

Symbol

Repetition

19.2kbps

Walsh1 to 7

Coder

1.2288 Mbps

1.2288 Mbps

1.2288

Mbps

1.2288

Mbps


I

Q

Walsh Code

Generator QShort Code

Long Code

Scrambling

19.2kbps

19.2

kbps

FIR

I Short Code

FIR

SR1 Reverse Radio Configurations


77/120

77

Radio Configuration 1 - Required

99 Backwards compat ible mode with TIA/EIABackwards compat ible mode with TIA/EIA --9595--BB

99 Based o n 9,600 bps Traff icBased on 9,600 bps Traff ic

Radio Configuration 2

99 Backwards compat ible mode with TIA/EIABackwards compat ible mode with TIA/EIA --9595--BB

99 Based on 14,400 bps Traff icBased on 14,400 bps Traff ic

Radio Configurations 3 and 4

99 Al l use new ISAl l use new IS--2000 cod ing fo r imp roved capaci ty2000 cod ing fo r imp roved capaci ty

99 RC3 is based on 9,600 bps and g oes up to 307,200 bpsRC3 is based on 9,600 bps and goes up to 307,200 bps

99 RC4 is based on 14,400 bps and goes up to 230,400 bpsRC4 is based on 14,400 bps and goes up to 230,400 bps

SR1 Reverse Channels


78/120

78

Each Mobile Transmits Several

Channels: 1 R1 R--Pi lotPi lot(Reverse Pilot)99 Includes Power Control SubIncludes Power Control Sub--ChannelChannel

1 R1 R--ACH or RACH or R--EACHEACH(Access or Enhanced Access Channel)

99 Used to Init iate CallsUsed to Init iate Calls

0 or 1 R0 or 1 R--CCCHCCCH(Common Control Channel)

99 Used to Init iate Calls in the Reservation Ac cess ModeUsed to Init iate Calls in the Reservation A ccess Mode

0 or 1 R0 or 1 R--DCCHDCCH(Dedicated Control Channel)

99 Prov ides Signaling while a Traff ic Channel is Ac tiveProvid es Signaling while a Traff ic Channel is Ac tive

0 or 1 R0 or 1 R--FCHFCH(Reverse Fundamental Channel)99 Primary Channel, usually VoicePrimary Channel, usu ally Voice

0 to 2 R0 to 2 R--SCHsSCHs(Reverse Supplemental Channels)

99 Carries High Speed DataCarries High Speed Data

R-FCH Coding for SR1(RC1,RC2)


79/120

79

1/2Rate

Vocoded

SpeechData

20 msec

blocks

Convolutional

Encoder

Interleaver

9.6

kbps

14.4

kbps

28.8

kbps

28.8

kbps

28.8

kbps

1.2288 Mbps

1.2288

Mbps


I

Q

1/3

Rate

Long Code

64-ary

Modulator

1 of 64

Walsh Codes

Walsh

Code 2

Walsh

Code 63

Walsh

Code 62

Walsh

Code 61

Walsh

Code 1

WalshCode 0

Long Code

Modulator

307.2

kbps

1.2288

Mbps1.2288 Mbps

Q Short Code

FIR

I Short Code

FIRt/ 2

1/2 Chip Delay

Reverse Error Protection


80/120

80

Uses Third-Rate Convolutional Encoder

Outputs Three Bits for Every Input Bit

Data Out

9600 bps

D DDDD D D D

+

+

Data

Out

9600

bps

+

Data In

9600kbps

Data Out

9600 bps

z z z z z z z z

z

z

z

14.4 Traffic Channel Reverse LinkModifications


81/120

81

Replaces 8 kbps Vocoder with

a 13 kbps Vocoder (both

Variable Rate)

Effects: Provides Toll Quality Speech

Uses a 1/2 Rate Encoder

Reduces Processing Gain 1.76

dB Results in Reduced Capacity

or Smaller Cell Sizes

1/2Rate

Vocoded

Speech

Data

20 msec

blocks


14.4

kbps28.8

kbps

64-ary Modulation


82/120

82

Every 6 Encoded Voice Data

Bits Points to one of the 64

Walsh Codes

Spreads Data from 28.8 kbps to307.2 kbps

(28.8 kbps * 64 bits) / 6 bits =

307.2 kbps)

Is Not the Channelization forthe Reverse Link

307.2kbps

28.8kbps

>

Walsh

Code 2

Walsh

Code 1Walsh

Code 0

Walsh

Code 63

Walsh

Code 62

Walsh

Code 61

Why Arent Walsh Codes Used for ReverseChannelization ?


83/120

83

All Walsh Codes Arrive

Together in Time to All Mobiles

From the Base Station

However, Transmissions fromMobiles DO NOT Arrive at the

Same Time at the Base Station

Reverse Channel Long Code Spreading


84/120

84

Long Code Spreading

Provides Unique Mobile

Channelization

Mobiles are Uncorrelated butnot Orthogonal with Each Other

Long Code

Generator

WalshModulated

Voice Data

XOR

307.2 kbps 1.2288 kbps

1.2288 kbps


85/120

Data Burst Randomizer


86/120

86

Algorithm

At 2400 bps rate ,

Transmission should occur on the PCG's numbered:

b0 if b8 = 0, or 2 + b1 if b8 = 1 (i.e. 1 out of PCG 0...3)

4 + b2 if b9 = 0, or 6 + b3 if b9 = 1 (i.e. 1 out of PCG 4...7)

8 + b4 if b10 = 0, or 10 + b5 if b10 = 1 (i.e. 1 out of PCG 8...11)

12+b6 if b11 = 0, or 14 + b7 if b11 = 1 (i.e. 1 out of PCG 12..15)

(Example)

( 25% Gated-On, 25% Gated-Off )

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

At 1200 bps rate ,

Transmission should occur on the PCG's numbered:

b0 if (b8 = 0 and b12=0), or 2 + b1 if (b8 = 1 and b12=1)

or 4 + b2 if (b9 = 0 and b12=0), or 6 + b3 if (b9 = 1 and b12=1) (i.e. 1 out of PCG 0...7)

8 + b4 if (b10 = 0 and b13=0), or10 + b5 if (b10 = 1 and b13=1)or 12 + b6 if (b11 = 0 and b13=0), or14 + b7 if (b11 = 1 and b13=1) (i.e. 1 out of PCG 8..15)

(Example)

(12.5% Gated-On, 12.5% Gated-Off)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Gated-On and Gated-Off Power


87/120

87

7 us 7 us

20 dB or to

the noise

floor (-60dBm)

3 dB

1.247 ms

Mean output of theensemble average

Ensemble average: Average of power control groups,

all with the same output power

Reverse Channel Short Sequence Spreading


88/120

88

Same PN Short Codes Are

Used by Mobiles

Short Sequence spreading Aids

Base Station Signal Acquisition Extra 1/2 Chip Delay is Inserted

into Q Path to Produce OQPSK

Modulation to Simplify Power

Amplifier Design

1.2288 Mbps


I

Q

1.2288 Mbps

I Short Code

FIR

I Short Code

FIRt/ 2

1/2 Chip Delay

1.2288

Mbps

OQPSK Modulation


89/120

89

QPSK Makes oneSymbol Change EveryPeriod

OQPSK Makes twoSymbol Changes EveryPeriod if Q DataChanges

Example Symbol Patternis:

- 00,10,01,11

I

Q

n

n n

n00 01

10 11

I

Q

n

n n

n00 01

10 11

CDMA Modulation Formats


90/120

90

Filtered Offset QPSKFiltered QPSK

I I

QQ

Mobile Station TX

Base StationPilot Channel TX

Reverse Pilot/Power Control Multiplexing(RC3,4)


91/120

91

MUX

Pilot Data

Power

Control Bits

To I Channel

Summer

One Power Control Group

Pilot PilotPilot PC Bits

312.5 us 312.5 us 312.5 us 312.5 us

1.25 ms

There are 16 Power Control Groups per 20 ms Frame

Each Power Control Group is Split into 4 Sub-Groups

1 Power Control Bit is Sent per Power Control Group Pilot and Power Control are Multiplexed Together

SR1, RC3 R-FCH Coding(RC3,RC4)


92/120

92

R-FCH

Data Bits

8.6 kbps

Walsh Code

Generator

1 Frame1/4 Rate

Convolutional

Encoder

38.4 ksps

Channel

Coder

Add CRC and

Tail Bits

9.6 kbps

Interleaver

1,1, 1, 1,-1, -1, -1, -1, 1,1, 1, 1,-1, -1, -1, -1

R-FCH Coding for a 20 ms Frame

Orthogonal

Spreading

Spread

Factor = 16

2 Reps

Symbol

Repeat

38.4 ksps 76.8 ksps 1228.8 kcps

R-FCH Carries Voice Information

Uses a 20 ms Frames Length

Using rate convolutional coding

ComplexR-SCH 2 Gain

SR1 Reverse Channel Spreading(RC3,RC4)


93/120

93

1,1,1,1,1,1,1,1,-1,-1,-1,-1,-1,-1,-1,-1

I Channel

Short Code

Generator

User Long

Code Mask

ComplexScrambling

Q

I+

+

+

-R-DCCH

R-Pilot +

Power

Control

R-SCH 1

orR-EACH

or

R-CCCH

R-FCH

Walsh 16

Generator

1,1, 1, 1 -1,-1, -1, -1, 1, 1, 1, 1, -1, -1, -1, -1

Walsh 2/4/8

Generator

1,-1 or 1 -1 1,-1, or 1,1,-1,-1,1,1,-1,-1

Walsh 16

Generator

1228.8 kcps

R-SCH 2

Walsh 4/8

Generator

1, 1, -1, -1 or 1, 1, -1, -1, -1, -1, 1, 1

Walsh 2

Generator

1,-1

Gain

Scale

GainScale

Gain

Scale

GScale

Deci

by 21228.8 kcps

1228.8 kcps

1228.8 kcps

1228.8 kcps

1228.8 kcps

1228.8 kcps

1228.8 kcps

1228.8 kcp

Q Channel

Short Code

Generator

1228.8 kcps

1-Chip

Delay

Long Code

Generator

1,1,1,1,-1,-1,-1,-1 for

R-EACH or R-CCCH

Channelization Summary


94/120

94

Function

9.6 kbpsConvolutional Encoder

14.4 kbps

Convolutional Encoder

Walsh Coding

Long Code

Spreading

Short Code

Spreading

Forward Link

(Base to Mobile)

1/2 Rate(9600 in 19200 out)

3/4 Rate

(14400 in 19200 out)

Channelization

Voice Privacy

Base Station

Identification

Reverse Link

(Mobile to Base)

1/3 Rate(9600 in 28800 out)

1/2 Rate

(14400 in 28800 out)

64-aryModulation

Channelization

Aid Base Station

Searching

CDMA Multiplex Sublayer


95/120

95

Layer 1Physical Layer

Channel Data - 9600 bps or 14400 bps

Multiplex SublayerTraffic Channel

Layer 2Link Layer

Paging & Access

Channels

Layer 2Primary Traffic

Layer 2Signaling

Layer 3

Call Processing & Control

Station Class Mark (SCM)


96/120

96

Extended SCMIndicator

7 Band Class 0 0XXXXXXXBand Class 1 1XXXXXXX

Dual Mode 6 CDMA Only X0 XXXXXXDual Mode X1XXXXXX

Slotted Class 5 Non-Slotted XX0XXXXXSlotted XX1XXXXX

IS- 54 Power Class 4 Always 0 XXX0XXXX

25 MHz Bandwidth 3 Always 1 XXXX1XXX

Transmission 2 Continous XXXXX0XXDiscontinous XXXXX1XX

Power Class for Band

Class "0" AnalogOperation( For CDMA only "00")

1- 0 Class I XXXXXX00

Class II XXXXXX01Class III XXXXXX10Reserved XXXXXX11

Function Bit(s) Setting

Ten Minutes in the Life of a CDMA MobilePhone


97/120

97

Turn-on

System Access

Travel

Idle State Hand-Off

Initiate Call

System Access

Continue Travel

Initiate Soft Handoff

Terminate Soft Handoff

End Call

CDMA Turn On Process


98/120

98

Find All Receivable Pilot Signals Choose Strongest One

Establish Frequency and PN TimeReference (Base Station I.D.)

Demodulate Sync Channel

Establish System Time

Determine Paging Channel Long CodeMask

Sync Channel Message

C t i th F ll i D t


99/120

99

Contains the Following Data:

Base Station Protocol Revision

Min Protocol Revision

Supported

SID, NID of Cellular System

Pilot PN Offset of Base Station

Long Code State

System Time

Leap Seconds From Start of

System Time

Local Time Offset from System

Time

Daylight Savings Time Flag Paging Channel Data Rate

Channel Number

SYNC

Read the Paging Channel

D d l t th P i


100/120

100

Demodulate the Paging

Channel:

Use Long Code Mask Derived

from the Pilot PN Offset Givenin Sync Channel Message

Decode Messages

Register, if Required by Base

Station Monitor Paging Channel

Pagin

g

CDMA Idle State Handoff


101/120

101

No Call In Progress

Mobile Listens to New Cell

Move Registration Location ifEntering a New Zone

Access Procedures

Controlled b BS b broadcasting Access Parameters


102/120

102

Controlled by BS by broadcastingAccess ParametersMessage on the paging channel

Access attempt is the process of sending one message and

receiving (or failing to receive) an ACK for that message= groups of access probe sequence

Access probe sequence = groups of access probes

Access probe = each transmission in an access attempt

Access Probe

Access Probe (or Access Channel Slot)


103/120

103

Access Channel Message

40 - 880 bits

Padding

as reqd

Frame Body

88 bits

T

8

Frame Body

88 bits

T

8

Access Channel Message Capsule

Access

Chan Frame96 b/20ms

Access

Chan Frame96 b/20ms

Access

Chan Frame96 b/20ms

Access

Chan Frame96 b/20ms

Access

Chan Frame96 b/20ms

Access

Chan Frame96 b/20ms

( )( 4 + PAM_SZ + MAX_CAP_SZ) x 20ms [ Max value = 26 frames ]

Preamble

(1 + PAM_SZ) x 20ms[ max = 16 frames ]

Access Channel Message Capsule

(3 + MAX_CAP_SZ) x 20 ms[ Max = 10 frames ]

Preamble

96 bits 0s

Preamble

96 bits 0s

PAM_SZ = No. of preamble frames

MAX_CAP_SZ = No. of message capsule frames

Access Probe Sequence


104/120

104

Access Probe Sequence

AccessProbe 1

Access

Probe 2

Access

Probe 3

Access

Probe n

TA TA TART RT RT

Preamble + Access Message Capsule

Max = 26 frames

RN RN RN RN

IP

P1

P2

P3

IP = Open Loop Power + NOM_PWR + INIT_PWR

where Open Loop Power = -( Received Power ) - 73

Access Attempt


105/120

105

RS : Backoff delay, which is random value between 0 to BKOFF slots

Process for Response MessagesProcess for Response Messages

message ready for

transmission

Access

Probe

Sequence

Access

Probe

Sequence

Access

Probe

Sequence

Access

Probe

Sequence

Access AttemptMAX_RSP_SEQ

RS RS RS

Access Attempt

P f R t MP f R t M


106/120

106

PD: (Persistence Delay) resulted from a pseudo-random test by MS; the first access probe of thesequence begins in the slot only if the test passes within that slot

The test result depends on the ESN, reason for attempt (call origination, register, etc.) and theaccess overload class of the MS, and a PSSIST value broadcasted by BS for that access class. If

the PSSIST is all 1s for some access class, the test for that access class will always fail

Process for Request MessagesProcess for Request Messages

message ready for transmission

Access

Probe

Sequence

AccessProbe

Sequence

AccessProbe

Sequence

AccessProbe

Sequence

Access AttemptMAX_REQ_SEQ

RS PD RS PDRS PDPD

Access Channel Messages

Registration Message


107/120

107

Registration Message - for registration as well as GlobalChalleng Authentication Process

Order Message - for transmission of order messages (e.g., BSchallengeorder, SSD update confirmation, MSacknowledgement order, etc.)

Data Burst Message - to get a trigger from the user to send amessage to BS (information message likeSMS)

Origination Message-MS information

Page Response message

Authentication Challenge Response Message

Status Response Message - response to BS status requestorder which may include MS terminalinformation, station class mark, service optionsupported, multiplex option support, IMSI, ESN,etc.

CDMA Call Initiation


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Dial Numbers, Then Press Send Mobile Transmits on a Special Channel Called the

Access Channel

The Access Probe Uses a Long Code Mask

Based On:bAccess & Paging Channel NumbersbBase Station ID

bPilot PN Offset

CDMA Call Completion


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Base Answers Access Probe using theChannel Assignment Message

Mobile Goes to A Traffic Channel Based on

the Channel Assignment MessageInformation

Base Station Begins to Transmit andReceive Traffic Channel

CDMA Soft Handoff Initiation

Mobile Finds Second Pilot of Sufficient Power (exceeds


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(

T_add Threshold)

Mobile Sends Pilot Strength Message to First Base Station

Base Station Notifies MTSO

MTSO Requests New Walsh Assignment from Second Base

Station

If Available, New Walsh Channel Info is Relayed to First

Base Station

Hard, Soft, and Softer Handoffs

Hard Handoff f2


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Break before make.

Soft Handoff

Make before break.

MS communicates with more

than one BS at a time.

Improves reception on cell

boundaries.

MS will receive different powercontrol from the two BSs.

Softer Handoff

MS communicates with more

than one sector of a cell. MS will receive identical power

control from both sectors.

f1

2

Hard Handoff

f1

f1

Soft Handoff

f1

Softer Handoff

Pilot Ec/ I0

cdma2000 CONCEPT: Soft Handoff

Terms:


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T_ADD

BS1 BS2

Pilot Ec/ I0

T_DROP

BS1 BS2

Active Set: MS is in soft

handoff.

Candidate Set: MS identifies asstrong.

Parameters:

T_ADD

T_COMP T_DROP

T_TDROP

Pilot Ec/ I0

0.5xT_COMP

BS1 BS2

CDMA Soft Handoff Completion

First Base Station Orders Soft Handoff with new Walsh


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Assignment

MTSO Sends Land Link to Second Base Station

Mobile Receives Power from Two Base Stations

MTSO Chooses Better Quality Frame Every 20 Milliseconds

MTSO

Base Station 1

Land Link

Vocoder/ Selector

Base Station 2

Ending CDMA Soft Handoff

First BS Pilot Power Goes Low at Mobile Station (drops


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below T_drop)

Mobile Sends Pilot Strength Message

First Base Station Stops Transmitting and Frees up Channel

Traffic Channel Continues on Base Station Two


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cdma2000 Standards Overview - TIA/EIA-98-D/E

I.e.3GPP2 C.S0011-A/B:


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Recommended Minimum Performance Standards for

cdma2000 Spread Spectrum Mobile Stations.

Important test sections:

2 Standard Radiated Emissions Measurement Procedure

3 CDMA Receiver Minimum Standards

4 CDMA Transmitter Minimum Standards

Covers both SR1 and SR3

No Minimum Standards specified for SR3.

This presentation only covers SR1 testing.

CDMA Service Options

Service Options Are:


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9911--Voice Using 9600 bp s ISVoice Using 9600 bps IS--9696--AA VocoderVocoder

9922--Rate Set 1Rate Set 1LoopbackLoopback(9600 bp s)(9600 bp s)

9933--Voice Usin g 9600 bps (EVRC)Voice Usin g 9600 bps (EVRC)

9944--Asy nch ronous Data Service (c i rcui t sw i tched)Asynch ronou s Data Service (c i rcui t sw i tched)

9955--Group 3 FaxGroup 3 Fax

9966--Sho rt Message Service (9600 bps )Sho rt Message Service (9600 bps )

9977--Internet Standard PPP Packet DataInt ernet Standard PPP Packet Data

9988--CDPD Over PPP Packet DataCDPD Over PPP Packet Data

9999--Rate Set 2Rate Set 2LoopbackLoopback(14400 bps)(14400 bp s)

991414--Sho rt Message Service (14400 bps)Sho rt Message Service (14400 bp s)

9932,76832,768--Voice Usin g 14400 bps (CDG)Voice Usin g 14400 bps (CDG)

Section 3 - Receiver Test

Receiver Test


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3.1 Frequency Coverage Requirements

3.4.1 Demod of Fwd Traffic Channel with AWGN

3.4.2 Demod of Fwd Traffic Channel with Multipath Fading

3.5.1 Receiver Sensitivity and Dynamic Range

3.5.2 Single Tone Desensitization

3.5.3 Intermodulation Spurious Response Attenuation3.5.4 Adjacent Channel Selectivity

3.5.5 Receiver Blocking Characteristics

3.7.1 Supervision Paging Channel

Section 4 - Transmitter Test

Transmitter Test


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4.1 Frequency Accuracy

4.2 Handoff

4.3 Modulation Requirements4.4 RF Output Power Requirements

4.4.14.4.1Range of Open Loop Output PowerRange of Open Loo p Outpu t Power

4.4.2 Time Response of Open Lo op Power Con trol4.4.2 Time Response of Open Lo op Power Con trol

4.4.3 Acc ess Probe Outpu t Pow er4.4.3 Access Probe Ou tpu t Pow er

4.4.4 Range of Closed Loop Pow er Control4.4.4 Range of Closed L oop Power Con trol

4.4.5 Maximum RF Outpu t Pow er4.4.5 Maximum RF Outpu t Pow er

4.4.6 Minimum Control led Outp ut Power4.4.6 Minimum Control led Outp ut Power

4.4.7 Standby Outpu t Power and Gated Ou tpu t Power4.4.7 Standb y Ou tput Power and Gated Ou tput Power

4.4.8 Pow er Up Funct ion Outpu t Power4.4.8 Power Up Func t ion Outpu t Power

4.4.9 Code Channel to Reverse Pilot Channel Output Power A ccu rac4.4.9 Code Channel to Reverse Pi lot Channel Outpu t Pow er Acc uracyy

4.4.10 Reverse Pilot Channel Transm it Phase Discon tinu ity4.4.10 Reverse Pilot Channel Transm it Phase Discon tinu ity

4.4.11 Reverse Traff ic Channel Outpu t Power During Changes in Da4.4.11 Reverse Traff ic Channel Outpu t Power During Changes in Datata

RateRate

CDMA Conclusions

New Access Method


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Code Based

Designed for Use in Interfering Environment

Uses Multipath to Improve Reception in Fading Conditions

cdma2000 is Backwards Compatible with TIA/EIA-95-B

Provides 2x Capacity Improvement Over TIA/EIA-95-B

99Improved CodingImproved Coding

99 Improved Modulat ionImproved Modulat ion

99 Coherent Reverse Link Demodulat ion (Mobi le Pilot)Coherent Reverse Link Demodulat ion (Mobi le Pi lot)

99 Fast Forward Lin k Power Contro lFast Forward Link Power Contro l

Has Options for Green Field and Overlay Operation:99 Direct Spread for Green Field Spectrum Appl icat ionsDirect Spread for Green Field Spectrum Appl icat ions

Supports High Speed Data for New Applications

cdma2000 fundamentals agilent

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