Introduction to WCDMA
Peter Muszynski, Harri Holma · 2010
This chapter introduces the principles of the WCDMA air interface. Special attention is drawn to those features by which WCDMA differs from GSM and IS-95. The chapter introduces the main parameters of the WCDMA physical layer. It describes the concept of spreading and despreading followed by a presentation of the multipath radio channel and Rake receiver. The chapter also discusses other key elements of the WCDMA air interface such as power control and soft and softer handovers. It describes the need for power control and its implementation and soft and softer handover. The chapter presents the main system design parameters of WCDMA and gives brief explanations. WCDMA is a wideband Direct-Sequence Code Division Multiple Access (DS-CDMA) system, i.e. user information bits are spread over a wide bandwidth by multiplying the user data with quasirandom bits derived from CDMA spreading codes. The chapter reviews the generic principles of CDMA operation. Controlled Vocabulary Terms multiaccess communication; power control; RAKE receivers