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WCDMA Physical Layer
WCDMA Physical Layer (Chapter 6)
Peter Chong, Ph.D. (UBC, Canada)
Research Engineer
Nokia Research Center, Helsinki, Finland
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WCDMA Physical Layer
Introduction
• This lecture presents a general WCDMA or UTRA (Universal
Terrestrial Radio Access) FDD (Frequency Division Duplex)
physical layer issues.
• Spreading and Scrambling
• Transport Channels
• Physical Channels
• Signaling
• Physical Layer Procedures
Mapping
to
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WCDMA Physical Layer
Some Parameters of WCDMA Physical Layer
Carrier Spacing 5 MHz (nominal)
Chip Rate 3.84 Mcps
Frame Length 10 ms (38400 chips)
No. of slots/frame 15
No. of chips/slot 2560 chips (Max. 2560 bits)
Uplink SF 4 to 256
Downlink SF 4 to 512
Channel Rate 7.5 Kbps to 960 Kbps
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WCDMA Physical Layer
Spreading and Scrambling
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WCDMA Physical Layer
Spreading Operation
• Spreading means increasing the signal bandwidth
• Strickly speaking, spreading includes two operations:
• Channelisation (increases signal bandwidth) - using orthogonal
codes
• Scrambling (does not affect the signal bandwidth) - using pseudo-
noise codes
Data
channelization codes (SF) scrambling codes
bit rate
chip rate
chip rate