Agilent Technologies 89410A Operator's Manual page 330

Wideband CDMA Concepts (Options B73, B79, and 080)
Problem/Cause
Noise floor increases at channel turn on
ü The channel that you are turning on uses a
different scramble code than that set in
analyzer.
Wrong channels marked as active
ü Poor signal-to-noise ratio.
ü All bits not transmitted within a physical
channel.
ü Data pattern induces large disparity in
power between slower channels overlaid
by the channel of interest.
Tslot and Tframe or tDPCH incorrect
(DATA? displayed in the symbol table)
ü Time gating is on and the gate length is
less than 3 slots (fewer slots introduce a
higher degree of false correlation on pilot
and sync signals).
24 - 18
Solution
Change the scramble code used to transmit the
channel to match that used by the Perch channel.
Increase signal power or remove cause of
noise/distortion.
Transmit all bits within a physical channel, or select
code-domain power for the layer associated with the
physical channel of interest (single-layer code-domain
power displays are accurate even if the analyzer is
unable to identify active channels in the composite
code-domain power display) .
Verify that your transmitter is transmitting properly.
Select 3 or more slots or turn off time gating.