汽车信息化-车联网.ppt

Group 7: Chen Liyue Su Jianfeng Huangcan Long Guangping LiKai
3G Technology
Sun Yat-Sen University
2012-11-21
2
Contents
1
Introduction
2
Core Technology
3
Main Standards
5
Conclusion
4
Applications
Introduction
3
Development munication Technology
1G
Late 1960s and early 1970s
Analog systems
Based on the Improved Mobile Telephone Service
Multiple standard
(NMT,TACS,etc.)

2G
The end of 1980s
Digital Systems
Better quality , higher capacity, lower cost
Multiple standard
(FDMA,TDMA)
Higher Rate Data;
Offer improved performance and capabilities
Include GPRS, EDGE
What is 3G?
4
3G is The Third Generation of Mobile phone standard and technology,superseding 2G,and preceding 4G.
3G
It is based on the International munication Union(ITU) family of standards and based on CDMA technology.
work of 3G
5
RAN
PSTN
work
CN
CS district
PS district
MSC/VLR GMSC
SGSN
GGSN
CN: work
RAN: Radio Access
Network
Characteristics
6
Seamless global coverage
Provide various types of high-quality multimedia services
Global roaming
Any kind munication at any time in any place
Compatible with works
A high level of security
Characteristics
Core Technology
7
1
Spread Spectrum
2
Code Division Multiple Access
3
Soft Handoff
8
C=B*log2(1+S/N)
Shannon:
transmit
receive
A data signal at the point of transmission bined with a higher data-rate
bit sequence (also known as a chipping code) that divides the data according to a
spreading ratio. The redundant chipping code helps the signal resist interference and also
enables the original data to be recovered if data bits are damaged during transmission.
Spread Spectrum
(1) anti-interference ability.
(2) broadband transmission, anti-fading ability.
(3) the ability of anti-interception.
9
CDMA system is based on code points technology (spread-spectrum technology) and multi-access technologies munication system, the system for each user assigned specific address.
Code Division Multiple Ac