Channel Power Measurement Concepts - Keysight X Series Measurement Manual

Concepts
MSR Measurement Concepts

Channel Power Measurement Concepts

Purpose
The Channel Power measurement is a common test used in the wireless
industry to measure the total transmitted power of a radio within a defined
frequency channel. This procedure measures the total power within the defined
channel. This measurement is applied to design, characterize, evaluate, and
verify transmitters and their components or devices for uplink and downlink
signals.
Measurement Method
The Channel Power measurement reports the total transmitted power and the
calculated power spectral density within the integration bandwidth. It takes a
sweep and the measurement acquires power in the channel.
The power calculation method used to determine the channel power is a
traditional method known as the integration bandwidth (IBW) method. The
measurement uses the frequency sweep mode, the RBW filter is set narrow
relative to the desired integration bandwidth. You can change the RBW and
VBW setings.It is important to correctly set the RBW before making this
measurement, because if the RBW filter setting is too narrow the signal will be
under-sampled and not all of the signal power will be measured. If the setting
is too wide, it will reduce the accuracy of the Channel Power measurement.
Span keys are not supported in MSR channel power because the span is
calculated automatically from integration bandwidths pre-defined for all
formats. Pre-defined integration BW values are the same as the defaults of
channel spacing. Therefore Integ BW in Meas Setup is not supported either.
The predefined Integ BW and RRC Filter values are defined in "Carrier Power
Measurement Bandwidth and Filter" on page 67.
To improve repeatability, you can increase the number of averages. The
channel power graph is shown in the graph window, while the absolute
channel power in dBm and the mean power spectral density in dBm/Hz are
shown in the text window.
54 Keysight N9083A & W9083A Measurement Guide