CDMA Technical Training

spectacularscarecrowΤεχνίτη Νοημοσύνη και Ρομποτική

17 Νοε 2013 (πριν από 3 χρόνια και 6 μήνες)

64 εμφανίσεις

CDMA Technical Training


Fundamental of CDMA technology


Technical background for Wavecom Wismo
Quick Q2338 CDMA Module


Q&A


IS
-
2000 Air Interface

Forward Link



Base

Station




Mobile

Station

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 Interface

Reverse Link



Base

Station



Mobile

Station

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 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

Mobile Station

Initialization

Mobile Station

Idle State

System Access

State

MS Control on

Traffic 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, or

Registers

Unable to receive

Paging Channel Message

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


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

T
x

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

R
x
: 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

System Connector
RF
FET
SRAM
ON/OFF
VBATT
CHG V
GPIO/AUDIO/Comm
A/D Bus
Serial Bus
VCC
VCC_A
RF Control
VCC_RX
VCC_TX
V_TCXO
V_PLL
V
Reg
V
Reg
V
Reg
V
Reg
V
Reg
V
Reg
FET
MSM5105
Keypad Bus
Key ON
CHG ON
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