Telecom Techniques Guide


Specifications of WCDMA

Channel Bandwidth  5 MHz
Duplex Mode  FDD and TDD
Downlink RF Channel Structure  Direct Spread (DS)
Chip Rate  3.84 Mcps
Frame Length  10 ms
Spreading Modulation  Balanced QPSK (downlink)

Dual-channel QPSK (uplink)

Complex spreading circuit
Coherent detection  • User dedicated time multiplexed pilot (downlink and uplink)

• common pilot in downlink
Channel Multiplexing in Downlink  Data and control channel are multiplexed
Channel Multiplexing in Uplink   • Control and pilot channel time multiplexed

• I&Q multiplexing for data and control channel
Multirate  Variable spreading and multicode
Spreading (uplink)  OVSF sequences. Gold sequence 241 for user separation (different time shifts in I and Q channel, truncated cycle 10 ms)
Spreading (downlink)  OVSF sequences for channel separation. Gold sequences 218-1 for cell and user separation (truncated cycle 10 ms)
Spreading Factors  4-256 (uplink), 4-512 (downlink)
Power Control  Open and fast closed loop (1.6 kHz)
Handover  Soft handover, Inter-frequency handover, etc.
Data Modulation QPSK (downlink), BPSK (uplink)
Channel Coding  Convolutional and turbo codes
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