Operating Manual Vol 1 - ES Documentation

SMIQDigital Standard 3GPP W-CDMA (FDD)2.14.3.2 3GPP W-CDMA Signals in the Frequency RangeFor information on 3GPP W-CDMA signals in the time domain, refer to section 2.14.3.1.The spectrum of a 3GPP W-CDMA signal (a DPCH channel) corresponds to that of a QPSK signal withidentical filter parameters.Fig. 2-147Magnitude spectrum of a 3GPP W-CDMA signalIf signals with several channels are investigated, a certain ripple may occur in the range +/-0.5 of thechip rate.Fig. 2-148Magnitude spectrum (section) of a 3GPP W-CDMA signal with several channelsThis effect can be influenced by the choice of the channelization codes and is reduced with increasingperiod of observation, i.e. higher averaging for the FFT settings.2.14.3.3 Effect of Data Source on the 3GPP W-CDMA SignalThe choice of the data sources is of vital importance for the signal characteristics. Especially theconstellation diagram and the crest factor can be modelled to a large extent by an appropriate dataselection.Since the number of channels can be very high, particularly in the downlink, this section deals only withthe simulation of downlink signals.In the following it is assumed that all channels are generated with the same scrambling code sequencesand the same channel powers of 0.0 dB.A symbol rate of 60 ksps is selected.1125.5555.03 2.225E-9