135Measuring Digital Communications SignalsSpectrum Emission Mask MeasurementsSpectrum Emission Mask MeasurementsThis section explains how to make the spectrum emission mask measurement on aW-CDMA (3GPP) mobile station. (A signal generator is used to simulate a mobilestation.) SEM compares the total power level within the defined carrier bandwidthand the given offset channels on both sides of the carrier frequency, to levels allowedby the standard. Results of the measurement of each offset segment can be viewedseparately.Step Action Notes1 Set up the signal source. a. Setup a W-CDMA uplinksignal.b. Set the source frequency to1,920 MHz (Channel.Number: 5 × 1,920 = 9,600).c. Set the source amplitudesto 0 dBm.2 Connect the source RFOUTPUT to the analyzerRF INPUT as shown.3 Select the mode. • Press Mode, SpectrumAnalyzer.4 Preset the analyzer. • Press Mode Preset.5 Set the radio standardand toggle the device tomobile station.• Press Mode Setup, RadioStd, 3GPP W-CDMA,3GPP W-CDMA, Device(MS).6 Set the center frequency. • Press FREQ Channel,1.920, GHz.
