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Chapter 15
Interference Analyzer Mode
Introduction
This chapter presents Interference Analyzer (Option 25) information and procedures.
Interference Analysis
Multiple wireless networks often operate in complicated signal environments. Three or four
base station antennas may be located on the same tower, and can create interference prob-
lems. Interference is one of the most common problems affecting wireless network systems
capacity and coverage. The Cell Master captures and analyzes a received signal and dis-
plays the air interface standard and estimated bandwidth of the received signal, which is
critical in recognizing and analyzing the interfering signals.
The Interference Analyzer option adds four measurements to the capability of the
MT8212B:
q
Spectrogram
q
Signal Strength
q
RSSI
q
Signal ID
Spectrogram
Spectrogram is a three dimensional representation of frequency, time and power useful for
identifying intermittent interference.
Procedure
The following procedure demonstrates common Interference Analyzer Spectrogram setup
options. To select Interference Analyzer mode:
Step1. On the Cell Master, press the MODE key, use the Up/Down arrow key to select
the
Interference Analyzer
mode and press ENTER .
Step2. Press the MEAS/DISP key followed by the
Spectrogram
soft key.
Step3.
Press the FREQ/DIST key to set up the desired frequency sweep. Choose the
appropriate soft keys and enter the start and stop frequency, the center frequency
and the span, or select the
Signal Standard
soft key and select the channel and
Uplink or Downlink.
Step4. To get the most effective spectrogram display, press the AMPLITUDE key, se-
lect the
Ref Level
soft key and set the reference level such that the largest signal
to be displayed will be near the top of the spectrum analyzer area of the screen.
The reference value required can be determined by observing the color of the
highest signal and changing the reference level to place that value near the top of
the spectrum analyzer area.
Step5. Select the
Scale
soft key and set the scale value to place the lowest signal near
the bottom of the screen. In general, 4 or 5 dB/division will be good values.
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