Wcdma (inglés)

Multi-Carrier WCDMA Basestation Design Considerations Amplifier Linearization and Crest Factor Control

Technology White Paper Andrew Wright Director, Product Research Oliver Nesper DSP Design Engineer
Issue 1: August, 2002 PMC-2021396 © 2002 PMC-Sierra, Inc.

Multi-Carrier WCDMA Basestation Design Considerations Amplifier Linearization and Crest Factor Control Technology White PaperAbstract
This paper presents issues to be considered when designing multi-carrier WCDMA basestations. Two topics will be the main focus of this discussion; the power amplifier linearization and the peak-to-average power reduction of a multi-carrier WCDMA signal, both of which are important for efficient operation of wideband power amplifiers and cost-effective design of the overall base station.WCDMA signal characterization, technology selection, linearization, and peak reduction methods are discussed.

About the Author
Andrew Wright is Director of Wireless and Signal Processing Product Research at PMC-Sierra. Dr Wright is a former co-founder and CTO of Datum Telegraphic Inc. and holds a Ph.D. in Microwave Engineering (meteorology). Since 1995, he has specialized in signal processingsolutions for third generation wireless systems. Oliver Nesper is a DSP Design Engineer in the Access Product Division. He has worked on the development of the PALADIN (Predistortion) and PALADIN Waveshaper products. Prior to that he was with Spectrum Signal Processing as a hardware development engineer working on the design of Soft Radio Receiver Platforms.

Revision History
Issue No.
1

IssueDate
August, 2002

Details of Change
Document created

PMC-2021396 (1) © 2002 PMC-Sierra, Inc.

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Multi-Carrier WCDMA Basestation Design Considerations Amplifier Linearization and Crest Factor Control Technology White Paper

Contents
Abstract.............................................................................................................................. 1 About theAuthor............................................................................................................... 1 Revision History................................................................................................................ 1 Contents............................................................................................................................. 2 List of Figures................................................................................................................... 3 List of Tables ..................................................................................................................... 4 1 2 Introduction................................................................................................................. 5 WCDMA SignalCharacteristics................................................................................. 6 2.1 3 4 WCDMA Signal Waveform Requirements .......................................................... 7 2.1.1 WCDMA Parameter Selection ............................................................... 9

BTS ArchitectureEvolution..................................................................................... 10 Amplifier Linearization and Efficiency Enhancement via Digital Predistortion ............................................................................................................. 13 4.1 4.2 4.3 Introduction ....................................................................................................... 13 Amplifier Linearization via Digital Predistortion................................................ 14 Amplifier Operating Point and Efficiency .......................................................... 17

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Waveshaping: A Method for Signal Combining and Signal Crest factor Reduction .................................................................................................................. 20 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 Introduction...