118 
Measuring Digital Communications Signals
Making Adjacent Channel Power (ACP) Measurements
Figure 9-3  ACP Measurement on a Base Station W-CDMA Signal
Two vertical white lines, in the center of the screen, indicate the bandwidth limits of the central channel being 
measured.
The frequency offsets, channel integration bandwidths, and span settings can all be modified from the default 
settings.
Offsets A and B are designated by the adjacent pairs of white lines, in this case: 5 MHz and 10 MHz from the 
center frequency respectively. 
10View the results using the 
full screen. 
• Press Full Screen. Press the Full Screen key again to 
exit the full screen display without 
changing any parameter values.
11 Define a new third pair of 
offset frequencies.
• Press Meas Setup, 
Offset/Limits, Offset, C, 
Offset Freq (On), 15, MHz.
This third pair of offset frequencies is 
offset by 15.0 MHz from the center 
frequency (the outside offset pair) as 
shown in Figure 9-4 Three further 
pairs of offset frequencies (D, E and F) 
are also available. 
Step Action Notes