Technical data

596 Chapter 20
W-CDMA or W-CDMA (with HSDPA) Over Air
Optional W-CDMA or W-CDMA (with HSDPA) Over the Air Measurement
Settings
W-CDMA or W-CDMA (with HSDPA)
Over Air
Setting the Scrambling Codes
The E7495A/B has two ways to identify the scrambling code being used by the
transmitter under analysis: an automatic detection mode,
Auto, and a
manually-specified mode,
Manual.
•In
Auto mode, the test set automatically detects the scrambling code present in
the signal.
•In
Manual mode, you enter the scrambling code instead of it being auto-detected
by the instrument.
If the scrambling code is known, its value can be entered and the test set can decode
and display the code domain power of the signal, even if no P-SCH and S-SCH are
present (a CPICH must be present, however). In normal operating conditions, these
sync channels are available, so the P-SCH and S-SCH are used by the E7495A/B
(and W-CDMA or W-CDMA (with HSDPA) mobiles) to determine the correct
sequence of scrambling codes required to demodulate the DPCH channels.
Setting the Transmitter Reference
You can set the W-CDMA or W-CDMA (with HSDPA) Over the Air display to
show the power in each channel as either relative power (dB) or absolute power
(dBm). The test set's default display mode is relative. In relative mode, the top
horizontal line (top-most graticule) of the display represents the total power
(channel power) in the 3.84 MHz bandwidth of that W-CDMA or W-CDMA (with
HSDPA) signal being broadcast by the transmitter. It is always 0 dB in this mode
since it is a relative measurement. The power in each channel is shown as a vertical
bar, with its height expressed in dB relative to the total channel power.
If you set the reference level mode to absolute, then the top graticule in the display
still corresponds to total channel power in the 3.84 MHz bandwidth. However, the
reference level and all the power values of the vertical bars showing the power in
Step Notes
1[Freq/Chan/Time Ref]
2 [Scramble C...]
3 [Auto] or [Manual] Each time you press this softkey, the
selected option changes.
In Manual mode, you can enter a number
using the keypad.