Thursday, April 9, 2009

Technical features of WCDMA

^ Radio channels are 5MHz wide.

^ Chip rate of 3.84 Mcps

^ Supports two basic modes of duplex: frequency division and time division. Current systems use frequency division, one frequency for uplink and one for downlink. For time division, FOMA uses sixteen slots per radio frame, whereas UMTS uses fifteen slots per radio frame.

^ Employs coherent detection on both the uplink and downlink based on the use of pilot symbols and channels.

^ Supports inter-cell asynchronous operation.

^ Variable mission on a 10 ms frame basis.

^ Multicode transmission.

^ Adaptive power control based on SIR (Signal-to-Interference Ratio).

^ Multiuser detection and smart antennas can be used to increase capacity and coverage.

^ Multiple types of handoff (or handover) between different cells including soft handoff, softer handoff and hard handoff.

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