HP 83236B S Interface manual Modulation Quality Rho

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Chapter 2, Making Measurements

Modulation Quality (Rho)

Modulation Quality (Rho)

Overview	In this measurement, the modulated signal is compared to an ideal, reference
	waveform to determine the performance of the transmitter’s modulation circuitry.
	Rho values are in the range of 0 to 1. A value of 1 indicates perfect correlation to
	the reference (high modulation quality). CDMA base station standards require
	that transmitters have rho performance of 0.912 or higher.

EVEN SECOND/ SYNC IN

(Rear Panel)

H

Transmitter Port

Even-Second Clock

SYNTH REF IN

Time Base

H

RF IN/OUT

Figure 8

CAUTION:

NOTE:

Requirements

Before performing any transmitter measurements, make sure that the power level applied to the RF IN/OUT port of the PCS Interface does not exceed the published limit. For CDMA base station signals this is 1 Watt (+30 dBm). You may have to use an external attenuator or directional coupler, depending on the power output for your transmitter. Signal levels greater than the specified maximum can cause damage to the test equipment.

The test procedures outlined in this section require that you have already configured the Test System as outlined in chapter 1, "Getting Started".

•Synchronization is required, so you must have an Even-Second Clock signal and a reference timebase (typically 19.6608 MHz) from the base station.

•You must have the ability to transmit the pilot channel only (Walsh 0).

•You must know the following about the base station and setup:

❒The base station channel number setting.

❒The PN Offset for the base-station-under-test. If you do not know the PN Offset, determine it by selecting Search for PN Offset in the main menu.

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Contents CDMA/PCS Base Station Test Software, User’s Guide Restricted Operating Overview Conventions Used in this Book Contents Making Measurements Receiver Sensitivity Operating Overview Setting the Test System Beep Glossary Index Getting Started Introduction Required Equipment You must supplySynth REF Load and Run the CDMA/PCS BS Test Software Tests Main Menu screen CDMA/PCS Test Software main menu features Configure the Software Select Configuration Information MenuScroll to and select your band of interest User k1 Perform Cdma Tests ProblemsIf You Had Perform Cdma Tests Making Measurements Making Measurements Overview Transmitter Measurements Receiver Measurements OtherOverview Average PowerRequirements Steps Information Menu under TX Measurement Path LossModulation Quality Rho Measurement not Correlating in , Troubleshooting, on Code Domain Power Menu Code Domain Timing Details on the use of the Code Domain Analyzer screen Code Domain Phase Already selected Transmit Spectrum AnalyzerSteps Go to Spectrum Analyzer @ Present Chan Steps Go to Spectrum Analyzer & Enter Freq Transmit Spectrum Receiver Sensitivity Main menu, enter the Base Station Channel number Error Rate FER is measured at each Eb/No level Receiver Performance in Additive NoiseEb/No Level Search for PN Offset PN Offset not Found Check for a valid clock signal from the base station Check Even-Second ClockCorrelating in , Troubleshooting, on Check Even-Second Clock Operating Overview Information ConfigurationReference Selecting a PCS Band To select a new PCS BandChannel plans for PCS Band selections Compensating for TX and RX Measurement Path Loss You must know the following loss valuesSaving Configuration Information to Memory BeepLoading Configuration Information from Memory Requirements StepsPurging Configuration Information from Memory Using Autostart Autostart FeatureTurning On Turning OffViewing Instrument Connections ConnectionsSetting the Test System Beep To Memory on Cdma Base Station Operating Overview Troubleshooting Troubleshooting Errors When Loading and Running the Software Memory Overflow ErrorsTest System Configuration Errors at Runtime Compensation not performed. Check Duplex OUT cable. Retry? Errors When Loading and Running the Software Errors While Attempting Measurements Cdma Measurement not CorrelatingErrors While Attempting Measurements Frame Error Rate Receiver Measurements Incorrect Base Station Channel entryErrors While Attempting Measurements Average Power Questionable Measurement ResultsRho Measurements Code DomainMeasurements Receiver TestsSensitivity tests random data not selected for signal source Questionable Measurement Results Glossary Glossary Modulation Quality See Rho Glossary Glossary Glossary Index Index FER Index Oqpsk PCS Qpsk UCT Walsh chip