cd ma final

8/8/2019 CD Ma Final

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CALL PROCESSING IN CDMA

MOBILE INITIALIZATION

INITIALISATION

IDLE

ACCESS

TRAFFIC


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MOBILE TRANSITION INTO DIFFERENT STATES

POWER-UP

Mobile

Initialization

State

Mobile

Idle

State

Mobile

System Access

State

Mobile

Traffic Channel

State


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PILOT & SYNCH

PAGING

ACCESS

TRAFFIC

INITIALIZATION

IDLE

SYSTEM ACCESS

TRAFFIC CHANNEL

INITIALIZATION

COMPLETE

BASE STATION

ACCESS

CALL SETUP

PILOT:

Power,phase,timing

Overhead info

Mobile Direct

Messages

Access messages

Messages

Voice

SERVICE SIGNALLING LAYER


4/28

MOBILE INITIALIZATION TO IDLE STATE

MOBILE SWITCHED ON

SCAN PN OFFSET 1-512

& MEASURE PILOT SIGNAL

STREGTH

SELECT BEST SIGNAL

PN OFF SET PILOT

READ SYNCH

CHANNEL

READ PAGINGCHANNEL

SID/NID

YES

NO

MOBILE IS NOWIN IDLE MODE


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MOBILE- PILOT CHANNEL ACQUISTION SUBSTATE

SCAN ALL PILOTS

F1 PN168 W32

F2 PN168 W32

F3 PN168 W32

Srch PN?? W0

PILOT SEARCHER SCANS THE ENTIRE RANGE OF PNs

LO

RF

Handset RAKE RECEIVER

Chips 0

PN 0

32 K

512

-20

0

Ec/Io

1

2

3

Rake Fingers

Reference PN

All PN Offsets


6/28

Go to Paging Channel, Get Configured

Access Parameters Msg

System parameters Msg

CDMA Channel List Msg

Extended System Parameters Msg

Neighbor List Msg

Global Service Redirection Msg

Read the Configuration Messages


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MOBILE IDLE STATE

Page ChannelMonitor & Pilot

Search

Sub state

Idle Handoff

Mobile System

Access State

Mobile Initialization

State

Mobile has fully

acquired system

timing

Idle Handoffcomplete

Mobile unable to

Receive Paging

Channel

Call Termination

Call Origination

Registration

Mobile receives

Acknowledgement to an

Access transmission

Other than origination or

Page response


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Slotted Mode & Quick Paging Channel

ObjectiveTo extend the battery life of a mobile in slotted mode by reducing

the time the mobile spends monitoring paging channels.

Slotted ModePaging channel divided into slots and slot cycles. Mobile monitors

specific slot in a slot cycle.

F-QPCH Functionality

Paging or configuration change indicators is sent out on theF-QPCH 100ms prior to the message on the F-PCH.

If the mobile cannot detect an indicator to be off, the mobile will

read the F-PCH slot immediately following the F-QPCH slot.


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SEQUENCE 1 2 Ns

Probe1 2 3 Np 1 2 3 Np Time

tg

Persistence

Test

PowerStep

tgIP

IP= -Mean Rx Power(dbm) +

OpenloopAdjust + ProbeInitialAdjust

ACCESS PROCEDURE


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ACCESS HANDOFF FEATURES

Access

Handoff

Mobile Traffic

Channel State

Access Entry

Handoff

Origination

Mobile (MS) searching for pilots Active-

Neighbors-Remaining State

No

Yes

BS sends general

Page to MS

MS performs access attempt. Up to

6 strongest pilots ind.

Active pilot in msg capsule

Channel Assignment into

Soft Handoff (CAMSHO)


11/28

The Traffic Channel State

From Mobile System

Access State

To Mobile

Initialization State

Traffic

Channel

Initialization

State

Conversation

Sub State

Release

Sub State

Waiting for

Mobile

Answer

Sub state

Waiting for

Order

Sub state

MS call termination MS receives

An Acknowledge order on

Forward traffic channelMS cell origination

MS receives an

Acknowledge order

On forward Traffic

Channel

MS userDisconnects or MS

Receives Release

Order

MS receives an

Alert order

MS user

Answers

call

MS receives

Release Order

MS receives

Release order


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CONVERSATION SUBSTATE

Messages being sent on the traffic channel

Continuous confirmation of the traffic channel

Locating handoff candidates

Performing handoffs

Power control

Overload control

Other call activities


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NAME

MIN

ESN

Location

Desired Slot Cycle

Station Class Mark Billing Information

BSC

HLR

REGISTRATION


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TYPES OF REGISTRATION

AUTONOMOUS

Power up

Power down

Timer based

Distance based

Zone based

NON-AUTONOMOUS

Parameter Change

Ordered

Implicit

Traffic Channel


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HANDOFFS

Idle Handoff when the mobile is in Idle state, the mobile may move from one cell to

another

HandoffDuring Access

Access Entry Handoff

Access Probe Handoff

Access Handoff

Channel Assignment into Soft Handoff

Soft Handoff make-before-break type of handoff

Inter Frequency handoff when the mobile has to retune to a different CDMA frequency

Traffic Channel HandoffsSoft Handoff

Soft-Softer Handoff

Softer Handoff

Hard Handoff


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CDMA Soft Handoff Mechanics

F1 PN168 W32

F2 PN168 W32

F3 PN168 W32

Srch PN?? W0

RAKE RECEIVER

LO

RFMSCBase Station A

Base Station B

Handset

Pilot

Ec/Io

Voice,Data,

Messages


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The Pilot Searching Process

Mobile reports

Results of search to

Base Station

Base Station

Alters Pilot SetsIf necessary

Mobile Searches

for strong

pilot signals


18/28

The Pilot Searching Process

ACTIVE SET

CANDIDATE SET

NEIGHBOR SET

REMAINING SET


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Neighbor Set Candidate

setActive Set Neighbor

Set

PilotStrength

T_ADD

T_DROP

(!) (2) (3) (4) (5) (6) (7) Time

Handoff Signalling


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Why Power Control

ObjectivesMaximum QOS

Maximum capacity

Minimize interference

Power Control Algorithm

Forward Link Power Control(FLPC, FPC)Reverse Link Power Control(RLPC, RPC)

Power Control is required

Near-far Problems

Path loss Fading

Performance Objectives


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Power Control

Mobile Tx Power (dBm) =

OPEN LOOP

k Mobile Receive Power(dBm)+ Parameters

+ Access Probe Corrections

+ CLOSED LOOP Corrections (dB)


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Reverse Link Power Control

Two separate algorithms

Reverse Open Loop (Autonomous Control)

Performed in the mobile

Adjust for path loss

Output Power based on received signal strength

Tx power = - [Mean Received Signal Strength] + correction_factors

Reverse Closed Loop (Base Station Directed Control)

Base Station directs mobile to adjust power

Controls frame error rate of signal received at the serving base station

Consists of an inner loop and an outer loop


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Reverse Link Closed Loop Power Control

Base Station sends power control bits

800 controls per second (800 Hz)

Closed Outer Loop (at base station)

Calculates Ec/Io set point

Based on R-FCH frame error rates

Closed Inner Loop (at base station)Compare Ec/Io set point with measured Ec/Io

Send power control bits(up/down) to mobile

Mobile Adjust its power

Based on power control bits from base station

Step size of its adjustable


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Forward Link Power Control

Reverse Link Closed Loop process is adopted

Mobile sends power control bits on R-PICH

800 control per second (800 Hz)

Based on Eb/Nt and FER objectives

Base station received power control bits

Variable power step size controlled by the base station


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VOCODERS

Vocoders compress speech, reduce bit rates

CDMA uses a superior Variable Rate Vocoder

Full rate during speech

Low rates in speech pauses

Increased capacity

more natural sound

Voice, signaling, and user secondary data may bemixed in CDMA frames


26/28

Variable Rate VocoderVocoder Data Rates

Rate set 1: 9600bps Tx Rate

Vocoder Data Rates

Rate set 2: 14.4Kbps Tx Rate

VocoderRate Tx Rate

Full 8550 9600

Half 4000 4800

Quarter 2000 2400

Eighth 800 1200

VocoderRate Tx Rate

Full 13300 14400

Half 6200 7200

Quarter 2700 3600

Eighth 1000 1800


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Variable Rate Vocoder

24 bits 48 bits 96 bits 96 bits 192 bits

Eighth Quarter Half Half Full

Rate Rate Rate Rtae Rate

20 msec 20 msec 20 msec 20 msec 20 msec


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Rate Sets

80 bits 8 bit CRC 8 Tail bits

40 bits 8 Tail bits

16 bits 8 Tail bits

Mode bit

Full Rate

HalfRate

QuarterRtae

Eighth Rate

1 171 bits 12 bit CRC 8 Tail bits

Rate Set 1

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