HP 83236B S Interface manual Rho Measurements, Code Domain, Receiver Tests

Chapter 4, Troubleshooting

Questionable Measurement Results

Rho Measurements	Sources of errors in rho measurement include the following:
	Input signal is outside the measurement range of the PCS Interface
	The specified range for rho measurements with the PCS Interface is
	−13 to +30 dBm (50 μW to 1 W) when testing base station transmitters. Verify
	that the signal applied to the RF IN/OUT port of the PCS Interface falls within
	this range before continuing with your tests.
	Channels other than the Pilot are on.
	For modulation quality measurements on a CDMA signal, you must have only the
	pilot channel active. If other channels (sync, paging, or traffic) are on, you will
	get poor rho readings, if you get readings at all. Turn off any other code channels,
	if they are on, before trying to re-measure rho.
	Other sources of interference exist in the channel.
	If other interference sources are present within the CDMA channel, you will see
	degraded rho performance. The spectrum analyzer modes may be used to search
	for other interference.
Code Domain	Sources of errors in Code Domain measurements include the following:
Measurements	Channels other than the Pilot are not turned up.
	Unlike the rho measurements example, code domain measurements require other
	code channels to be turned on. In most cases, in addition to the Pilot channel, you
	will have a sync channel, a paging channel, and one or more traffic channels
	enabled.
Receiver Tests	Sources of errors in receiver tests include the following:
	Cable loss values are incorrect
	Since the Software will compensate for cable loss between the Test System and
	your base station’s receiver test port, it is very important that you have the co rrect
	values entered into the Configuration Information Menu.
	You can view the loss values in the Configuration Information Menu. If
	they do not match your setup (do not forget to allow for losses through couplers,
	attenuators, and so forth) go to RX Measurement Path Loss and enter the
	correct value.

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