User`s guide

Signal Analyzer Mode 4
E6651A User’s Guide 67
Figure 39 Spectrum Measurement Menu (Screen 2 of 2)
FFT Start Position The FFT Start Position represents the time index at which
the FFT input begins. The index value is a sample of the
mobile WiMAX 5 ms frame. With the Test Set sampling
frequency of 40 MHz, the index values can range from
1- 200,000. The starting time and ending time of the sample
are calculated and displayed as “S:” and “E:” respectively.
Average This sets the number of consecutive measurement results
averaged to produce the spectrum display. The available
range is 0- 100 frames.
Max Hold Set to ON to display the frequency component with
the maximum signal amplitude.
Trac e Set to ON to trace up to five signal frequency
components.
Time Gate Mode Disable to determine the average spectrum
information of a single Mobile WiMAX frame without the
need for frame synchronization or knowledge of the exact
starting point of the frame.
Marker Use to display the Marker Menu. The Marker functions can
only be used for an RF input source. A detailed description
of the Marker Menu is provided in “Marker Menu" on
page 69.
Max Hold
Trace
Time Gate Mode