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Multi-Carrier and Spread Spectrum Systems: From OFDM and MC ...

Multi-Carrier and Spread Spectrum Systems: From OFDM and MC ...

Multi-Carrier and Spread Spectrum Systems: From OFDM and MC ...

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46 FundamentalsOrthogonalV-SF code<strong>From</strong> otherusersScramblingcodesDataChannelcoding &interl.Mapper(QPSK)MUX<strong>Spread</strong> signalTransmitterPilot &power control<strong>From</strong> otherusersMatched FilterReceivedUL-signalReceiverChanneldecoding &de-interl.Soft demapperCoherent rakecombinerMFMFAntenna 1Antenna 2ReceivedspreadsignalFigure 1-15Simplified block diagram of a WCDMA/UMTS base station transceiverOrthogonal variableSF code #kScramblingcodesUser #kdataChannelcoding &interl.Mapper(QPSK)<strong>Spread</strong> signalTransmitterReceivedDL-signalChanneldecoding &de-interl.Soft demapperIntegratorOrthogonalvariable-SFcode #kScramblingcodesReceivedspreadsignalReceiverMatched FilterFigure 1-16Simplified block diagram of a WCDMA/UMTS terminal station transceivering <strong>and</strong> modulation. The set of HSDPA <strong>and</strong> HSUPA is termed high speed packed access(HSPA). In Table 1-15 the important parameters of HSPA are summarized.1.4 <strong>Multi</strong>-<strong>Carrier</strong> <strong>Spread</strong> <strong>Spectrum</strong>The success of the spread spectrum techniques for second-generation mobile radio <strong>and</strong><strong>OFDM</strong> for digital broadcasting <strong>and</strong> wireless LANs motivated many researchers to investigatethe combination of both techniques. The combination of DS-CDMA <strong>and</strong> multi-carriermodulation was proposed in 1993 [7, 12, 22, 24, 35, 50, 55]. Two different realizationsof multiple access exploiting multi-carrier spread spectrums are detailed in this section.

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