Transcript CDMA Technical Training

CDMA Technical Training
• Fundamental of CDMA technology
• Technical background for Wavecom Wismo
Quick Q2338 CDMA Module
• Q&A
IS-2000 Air Interface
Forward Link
Pilot (F-PICH)
Paging (F-PCH)
Base
Station
Sync (F-SYNC)
Fundamental (F-FCH)
Supplemental (F-SCH)
Quick Paging Channel (F-QPCH)
Mobile
Station
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 Interface
Reverse Link
Pilot (R-PICH)
Access (R-ACH) or R-CCCH
Base
Station
Dedicated Control (R-DCCH)
Fundamental (R-FCH)
Supplemental (R-SCH)
Mobile
Station
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 MHz
Mobile Rx: 869.04MHz – 893.97 MHz
• Band Class 1 (PCS Band)
1850 MHz – 1909.95 MHz
1930 MHz – 1989.95 MHz
CDMA Call Processing
Power-Up
•Synch Channel MSG
Received
•Pilot Channel Acquired
•MS Acquires System
Timing
Mobile Station
Initialization
End Use of
Traffic Channel
Unable to receive
Paging Channel Message
Mobile Station
Idle State
Receives Page
Originates, or
Registers
System Access
State
MS Control on
Traffic Channel State
Directed to Traffic Channel
Receipt of
Acknowledgement
to other than
Origination or
Page 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
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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 Specification
RF
Q2338 Hardware Specification
Baseband
Flash
SRAM
MSM5105
GPIO/AUDIO/Comm
Keypad Bus
FET
VReg
VReg
CHG ON
VReg
FET
VReg
VBATT
VReg
ON/OFF
VReg
VCC
VCC_A
VCC_RX
VCC_TX
V_TCXO
V_PLL
RF
RF Control
CHG V
Serial Bus
Key ON
System Connector
A/D Bus
Q2338 Software Architecture
Features Summary
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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
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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
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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:
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CDG Testing in MTNet
CDG 1 type testing in China TTL
Emission testing in China TTL
User trial done by China TTL
Q2338 Integration
RF Antenna
Q2338 Module
External Antenna
Host Device
UART
60 Pin System
Connector
R-UIM
MIC/SPK
LCD
60 Pin System
Connector
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