CDMA Technical Training

• Fundamental of CDMA technology

• Technical background for Wavecom Wismo Quick Q2338 CDMA Module

• Q&A

IS-2000 Air InterfaceForward Link

Base

StationMobileStation

Pilot (F-PICH)

Paging (F-PCH)

Sync (F-SYNC)

Fundamental (F-FCH)

Supplemental (F-SCH)

Quick Paging Channel (F-QPCH)

Forward Link Channels

• Forward Pilot Channel (F-PICH)

– Shared by the mobiles

– Provide timing and phase information of the cell

– Used for cell acquisition and handoff by the mobile

• Forward Sync Channel (F-SYNC)

– Used by the mobiles to acquire initial time synchronization

• Forward Paging Channel (F-PCH)

– Used to send control information and paging messages

• Forward Fundamental Channel (F-FCH)

– Traffic channel carrying voice and data

• Forward Supplemental Channel (F-SCH)

– Used (but not limited) to carrying high speed data

IS-2000 Air InterfaceReverse Link

Base

Station

MobileStation

Pilot (R-PICH)

Access (R-ACH) or R-CCCH

Dedicated Control (R-DCCH)

Fundamental (R-FCH)

Supplemental (R-SCH)

Reverse Link Channels

• Reverse Access Channel (R-ACH) and Reverse Common Control Channel (R-CCCH)– Used for communication of layer 3 and MAC messages from the

mobile to the base station• Reverse Pilot Channel (R-PICH)

– Time tracking– Power control measurements

• Reverse Dedicated Control Channel (R-DCCH)– Used for call set up

• Reverse Fundamental Channel (R-FCH)– Voice and data traffic channel

• Reverse Supplemental Channel (R-SCH)– Used for data calls– MSM5105 supports up to 78.6 kbps R-SCH rate

CDMA Band Classes

• Band Class 0 (Cellular Band)Mobile Tx: 824 MHz – 848.97 MHzMobile Rx: 869.04MHz – 893.97 MHz

• Band Class 1 (PCS Band)1850 MHz – 1909.95 MHz1930 MHz – 1989.95 MHz

CDMA Call Processing

Power-Up

Mobile StationInitialization

Mobile StationIdle State

System Access State

MS Control onTraffic Channel State

•Synch Channel MSG Received

•Pilot Channel Acquired

•MS Acquires System Timing

Directed to Traffic Channel

End Use of Traffic Channel Receives Page

Originates, orRegisters

Unable to receive Paging Channel Message

Receipt of Acknowledgement

to other thanOrigination orPage Response

message.

CDMA Handoffs

• The process whereby a Mobile Station moves to acquiring a new traffic channel

• CDMA implements various types of handoff schemes to reduce call drop rate– Soft Handoff– Softer Handoff– Soft-softer Handoff– Hard handoff

Type of CDMA Handoffs

• Softer Handoff: Mobile Station communicates with sectors within the cell.

• Soft Handoff: “Make before Break”. Mobile communicates with two cells.

• Soft-softer Handoff: Mobile Station communicates with two sectors within a cell and another sector or cell.

Soft Handoff Advantage

• Reduce call drop rate – “Make before Break”

• Improve capacity– Path diversity allows mobile to reduce transmit

power to the level only the closest cell needs– Less power means less interference– Less interference means more mobiles can

access the network

Power Control

• Reverse Link Power Control– BTS instructs Mobile Station to raise or reduce

power level based on received signal quality

• Forward Link Power Control– BTS raise or reduce its transmit power level

based on FER reports from Mobile Stations

Reverse Link Open Loop Power Control

• Mobile station adjusts its transmit power level based on received signal quality.

• Mobile transmit power based on Open Loop Power Control

Tx = -Rx-K+(NOM.PWR-16*NOM.PWR.EXT)+Sum of Access Probe Corrections (dBm)

Rx: Mean input receive power

NOM.PWR: nominal power (dB), part of system parameter

NOM.PWR.EXT: nominal power for extended handoff, part of system parameter

K: 76 for cellular and 73 for PCS

Reverse Link Closed Loop Power Control

• Closed loop power control attempts to compensate for multipath fading losses

• BTS instructs Mobile to adjust its transmit power in a 1dB step size: “0” = -1 dB,

“1”=+1dB

• Response time: 1.25ms

Forward Link Power Control

• BTS collect FER report from the Mobile Station and makes decision on adjusting its transmit power

• Prevents excessive interference to other cells while maintaining a desired Fram Error Rate

Power Control Advantage

• Reduce uneccessary interference resulting in improving capacity

• Extend battary talk time

• Less power = less RF polution

Q2338 Hardware Specification

• RF – RF block diagram– Transmitter features and specifications– Receiver feature and specification

• Baseband– System connector– Memory specification– Power consumption

Q2338 Hardware SpecificationRF

Q2338 Hardware SpecificationBaseband

Sy

ste

m C

on

ne

cto

r

RFFET

SRAM

O N/O FF

VBATT

CHG V

G PIO /AUDIO /Comm

A/D BusS

eria

l Bu

s

VCC

VCC_A

RF

Co

ntro

l

VCC_RX

VCC_TX

V_TCXO

V_PLL

VReg

VReg

VReg

VReg

VReg

VRegFET

MSM5105

Keypad Bus

Ke

y O

N

CHG O N

Flash

Q2338 Software Architecture Features Summary

• IS2000 Rel.0 1X, IS-95A/B protocols• Two way SMS• Voice (8K EVRC, 13K QCELP)• Packet (153kbps) and Asynchronous data services (9.6kbps,14.4kbps)• Fax (Class 2.0 Group 3)• R-UIM/SIM, UART (up to 230kbps), USB• TCP/IP/PPP and Sockets• Secure Socket Layer• OTASP/OTAPA• Authentication and Encryption• Voice Privacy• System Determination 1.0 and 2.0, Preferred Roaming Support• Mobile IP• Voice Recognition (optional, extra license)

Q2338 Software Architecture Tools

• Flash Downloader

• RF Calibration (auto and manual)

• RF tester (In-house use only)

• UPST (Universal Product Support Tool)

• UDM (Universal Diagnostic Monitor)

• ESN Tool

• Remote Development Environment (Remote MMI/Application Simulation and Development)

Q2338 CDG Testing

• Will comply with US CDG testing process• CDG 1

– Third party test house– Internal testing using Spirent C2K AirAccess Test

System

• CDG 2– Submitting to Interoperability Labs at Lucent, Nortel

and Motorola

• CDG 3– Cooperation with the carriers for field testing

Q2338 CDG 1 Testing

• In house Testing with Spirent

• Testing based on IS-98D – RF Parametric Tests: Receiver Sensitivity, for

example– Basic Call Processing Test: Idle Handoff test,

for example

• Serves as entrance criteria to CDG 2

Q2338 CDG 2 Testing

• Infrastructure interoperability testing

• Testing based on IS-898– Handoff tests– POTS tests– Asynchronous Data tests– High Speed Data tests– Fax test

Q2338 CDG 3 Testing

• Field testing with Carriers

• Formal CDG 3 testing requires Carrier participation as certain network parameters need to be adjusted

CDMA Testing in China

• Same testing standards as in the US

• Need “Network Access Certificate” from MII:– CDG Testing in MTNet– CDG 1 type testing in China TTL– Emission testing in China TTL– User trial done by China TTL

Q2338 Integration

Q2338 Module

RF Antenna

60 Pin System Connector

Host Device

External Antenna

60 Pin System Connector

UART

R-UIM

MIC/SPK

LCD

Q2338 Integration: RF Antenna

• Three options available– Soldering on directly provide that antenna

already has 50 ohm line– Matcing circuit

• Open space available for matching circuit if not 50 ohm line

– RADIALL Sprint board connection