Digital Power Meter Display, 5000-NG
47
Interpreting Statistical Data
There are many factors that influence the performance of modern
communications systems. Some examples:
The presence of interfering signals within the operating bandwidth of
the system.
Transmission line discontinuities resulting in multiple reflections within
the transmission system.
Poor amplifier linearity caused by amplifier compression. This results in
signal distortion and poor fidelity of transmitted waveforms.
Antenna damage or degradation resulting in high transmission system
reflections.
Issues with transmitter modulator performance resulting in high error
vector magnitude (EVM).
Many of the above transmission system issues may be identified through the use
of the statistical techniques mentioned above. For example, if a particular LTE
radio system was known to be dropping calls at a higher rate than expected, a
service technician will need to know whether the problem is with the radio
itself, or with some element of the transmission system, or with the air
interface.
Measuring the statistics of the base station radio, while terminated with a high
quality 50 ohm termination, and then again with the radio connected to the
transmission and antenna system will provide clues as to where the issues may
be.
