|
|
|
|
|
|
WCDMA (UMTS)
TDCDMA
CDMA2000
WCDMA (DoCoMo)
TD-SCDMA
|
|
Mobiles
Bluetooth
HomeRF/SWAP
WAP
GPRS, HSCSD
EDGE
CAMEL, IN
|
|
TD-SCDMA
Time Division Synchronous CDMA (TD-SCDMA) was proposed by China Wireless Telecommunication Standards group (CWTS) and approved by the ITU in 1999 and technology is being developed by the Chinese Academy of Telecommunications Technology and Siemens. TD-SCDMA uses the Time Division Duplex (TDD) mode, which transmits uplink traffic (traffic from the mobile terminal to the base station) and downlink traffic (traffic from the base station to the terminal) in the same frame in different time slots. That means that the uplink and downlink spectrum is assigned flexibly, dependent on the type of information being transmitted. When asymmetrical data like e-mail and internet are transmitted from the base station, more time slots are used for downlink than for uplink. A symmetrical split in the uplink and downlink takes place with symmetrical services like telephony.
TD-SCDMA Technical Summary
Frequency band: 2010 MHz - 2025 MHz in China (WLL 1900 MHz - 1920 MHz)
Minimum frequency band required: 1.6MHz
Frequency re-use: 1 (or 3)
Chip rate: 1.28 Mcps
Frame length: 10ms
Number of slots: 7
Modulation: QPSK or 8-PSK
Voice data rate: 8kbit/s
Circuit switched services: 12.2 kbits/s, 64 kbits/s, 144 kbits/s, 384 kbits/s, 2048 kbits/s
Packet data: 9.6kbits/s, 64kbits/s, 144kbits/s, 384kbits/s, 2048kbits/s
Receiver: Joint Detection, (mobile: Rake)
Power control period: 200 Hz
Number of slots / frame: 7
Frame length: 5ms
Multi carrier option
Handovers: Hard
Smart antennas
Baton handover
Uplink synchronisation
Physical layer spreading factors: 1, 2, 4, 8, 16
|
|
