Tài liệu W­CDMA technology  and FOMA installation plan pdf

Today’s Items Principle of CDMA - Frequency allocation - Principle of DS-CDMA - Transmit power control Basic W-CDMA Transmission Technologies - Two-layer spreading code assignment -

W-CDMA technology

and FOMA installation plan

3rd September, 2002 Network planning Dept.

NTT DoCoMo

Today’s Items

Principle of CDMA

- Frequency allocation

- Principle of DS-CDMA

- Transmit power control

Basic W-CDMA Transmission Technologies

- Two-layer spreading code assignment

- Inter-BS asynchronous mode

Characteristics of W-CDMA

- Statistical Multiplexing effect

- MS stand-by time

- Coherent RAKE reception (RAKE time diversity)

3G Roll Out Plan

- FOMA service content

- 3G Roll out plan

In case of 3 cell repetition

Frequency Allocation

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f3

f1

f1

f3

f2

f1

f3

f1

f3

f2

f2

f1

f3

f3

f2

f3

f2

Same frequency in all area.

Take care of frequency allocation.

Principal Diagram

Frequency Synthesizer

Channel

Coding Modulation Data

Spreading Code ~

Spreading

~

Filter Data

Demodulation Decoding Channel

Spreading Code Frequency

Synthesizer Despreading

W

B(5MHz) B(5MHz)

SF (spreading factor)=

Symbol rate of transmitted data Chip rate of spread data

Principal Diagram

(Waveform of spreading codes in DS-CDMA)

1

-1 1 1 1

1 -1

1 -1

1 -1

1 -1

1 -1

-1 1 -1

1 1 -1-1-1-1

1 1

0 -2

0 0 0

2 2

-2

1 -1

1 -1

1 -1

1 -1

1 -1 1 1 1

Integrate

& dump

User 1

User 2

Transmitted data sequence

Spreading code

Spreading code

Composite signal

Spreading code

Recovered transmitted data sequence for user 1

receiver User 1

Integration over the symbol length to recover

despreading

despreading

Power control

Transmit Power Control

MS

MS

MS

MS

Near – far problem

Node B

Node B

TPC

is essential Minimize the Tx power Increase the system capacity

SIR measurement

TPC bit

Target SIR

SIR

Up Link

Transmit power control

Closed loop transmit power control in the Uplink

Tslot Transmit Power Control

Down Link

1dB step

Today’s Items

Principle of CDMA

- Frequency allocation

- Principle of DS-CDMA

- Transmit power control

Basic W-CDMA Transmission Technologies

- Two-layer spreading code assignment

- Inter-BS asynchronous mode

Characteristics of W-CDMA

- Statistical Multiplexing effect

- MS stand-by time

- Coherent RAKE reception (RAKE time diversity)

3G Roll Out Plan

- FOMA service content

- 3G Roll out plan

Two-layer Spreading Code Assignment

Scrambling Code

10m sec length (38,400 chip)

Channelization Code

4 chip

　　 |

512 chip

X

transmission data is spread by scrambling codes and channelization codes Extremely large number of scrambling code can be used.

Elimination of interference components

How to use (1/2)

Down Link

Scrambling Code Channelization

Code

Up Link

MS (A)

Scrambling Code

MS (B)

Node-B

Node-BChannelization

Code

How to use (2/2)

Scrambling Code -To identify cells.

-Code shall be assigned to each cell.

-Number of Code ; 512

-Assignment work by System Designer is required.

-To identify Users.

-Code shall be assigned to each user.

-Number of Code ; 224

-Assignment work by System Designer is not required.

Channelization Code -To identify the channels to

be used in a cell.

-Code shall be assigned to each user.

-To identify the channels

to be used in a user.

-Code shall be assigned to each channel.

Summary

Inter-BS Asynchronous mode (1/2)

Code Assignment in Downlink

-comparison between Asynchronous and Synchronous at inter-cell

Cell-A

Cell-B

Cell-C

Sc ra

m bl

in g

Co de

Ch an

ne liz

at io

n

Co de

A set of Orthogonal Multi-SF Code

Inter-cell Asynchronous

Cell-A

Cell-B

Cell-C

Time Shift

Sc ra

m bl

in g

Co de

Ch an

ne liz

at io n

Co de

GPS

GPS

Outer Timing Source

Inter-cell Synchronous

Benefit of Asynchronous

- No need Outer Timing Source.

- Flexibly implement in-door service in code planning.

- Available to assign the same channelization

code in each cell.

- In Downlink, easy to assign scrambling code

because of many code available as 512.

Inter-BS Asynchronous mode (2/2)

Today’s Items

Principle of CDMA

- Frequency allocation

- Principle of DS-CDMA

- Transmit power control

Basic W-CDMA Transmission Technologies

- Two-layer spreading code assignment

- Inter-BS asynchronous mode

Characteristics of W-CDMA

- Statistical Multiplexing effect

- MS stand-by time

- Coherent RAKE reception (RAKE time diversity)

3G Roll Out Plan

- FOMA service content

- 3G Roll out plan

1.0

1.5

2.0

2.5

10%

1%

Outage=0.1%

Voice Activity=0.4

Capacity C

User #1 User #2 User #3 User #4 User #5 User #6 User #7

Active C user OK!

(C+1)user

Statistical Multiplexing Effect

Rx.OFF

Rx OFF

ON

Low bit-rate

common

control

channel

MS Stand-by Time

High bit-rate

common

control

channel

ON

Wideband accelerates the bit rate in the control channel, And make it possible to reduce the rate of intermittent reception.

Node B

Coherent RAKE Reception (RAKE time diversity)

Coherent Rake combining

Delay time

Narrow-band received signal

MS

Multi-pass

Wide-band received signal

Power

Estimation filter

Channel decoder

Recovered data

Rake combiner

Radio transmitted environment

in urban area

Wide-band High resolution High efficiency of Rake combiner

7.68Mcps

1 µ s

Delay profile

Node B1

Selection combining

Site Diversity

MS

Node B2 Node B1 Node B2

MS

Replica generating

Site Diversity ( Field trial )

Added Akasaka-site

Delete Aoyama-site

0 20 40 60 80

Akasaka-site Aoyama-site

0 5 10 15 20

E b

time

time