Time-Domain Displays - Agilent Technologies 89410A Operator's Manual

Time-Domain Displays

The analyzer provides several time-domain displays, including a symbol table that
shows the demodulated bits with error parameters such as RHO, Frequency Error,
and EVM.
Composite Time Domain
The composite time-domain display is the filtered, detected time-domain signal and
shows power (in dB) versus time for all channels. This display is useful for VOX
on/off and transmission power control measurements.
Other Time-Domain Displays
The remaining time-domain displays (including the symbol table) show IQ data for
a single layer. The [code layer] and [code channel] softkeys (under the [Time] hardkey)
determine which layer is displayed. You can view the symbol table or the IQ
measured or IQ reference signal for the selected layer.
Tip
To quickly set the [code layer] and [code channel] softkeys, display composite
code-domain power, place the marker on the desired layer and channel, then press
[Marker →], [mkr → layer/channel].
The symbol table shows the final product of digital demodulation—the binary bits
for each symbol in the selected channel and layer. In addition, the symbol table
displays information about the W-CDMA signal and error parameters, such as ( For
more details about these error parameters, see the analyzer's online help):
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The IQ measured signal is the result of resampling the data to an integer number of
points per symbol and applying system gain normalization, carrier locking, and
root-cosine filtering to the incoming signal.
The IQ reference signal provides a powerful analysis technique and involves
comparing the demodulated signal with an ideal signal generated from detected
bits. The analyzer detects bits from the measured IQ signal and reconstructs a
sequence of ideal I and Q states. These are then treated as ideal impulses. The
resultant IQ reference can be overlaid or compared side-by-side with the IQ
measured signal.
The scramble code used to demodulate the W-CDMA signal.
The slot number of the first slot in the measurement.
T frame—how far the slot is offset (in slots) from the Perch channel (not used
for 3GPP 1999 forward link W-CDMA signals).
T slot— how far the slot is offset (in symbols) from the Perch channel (not used
for 3GPP 1999 forward link W-CDMA signals).
T Trigger—the amount of time, in chips, from the trigger to the start of the sync
symbol.
tDPCH—the tDPCH time value for the DPCH on the selected code channel (only
used for 3GPP signals).
pilots—the number of pilot bits detected in the DPCH for the selected code
channel (only used for 3GPP signals).
RHO, EVM, frequency error, magnitude error, and phase error.
Wideband CDMA Concepts (Options B73, B79, and 080)
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