3G通讯的发展与应用趋势.pdf

文档介绍：: .
3G通訊的發展
cdmacdma
NMT TDMATDMA 20002000
IS-136IS-136
TD-
其它 TD-
PDCPDC SCDMASCDMA
3G provides customers and operators with complete integrated service solutionsMultiple Access Technologies
CDMA Time
Code
Based on codes, all users
User3 obtain traffic channels at
the same time and on the
User2
same frequency band, for
User1 example, WCDMA and
CDMA2000
TDMA Frequency
Time
… … Traffic channels at
User 2 User 10 different time slots are
allocated to different
User 1 User 9 users, for example,
FDMA DAMPS and GSM
Time Frequency
User 1 User 2User 3 Traffic channels on
different frequency bands
are allocated to different
Frequency users,for example, AMPS
and TACSObjectives of 3G
 Globally universal frequency band and standard, global