R&S ESCI Analyzer - MEAS
1166.6004.12 4.151 E-1
Channel and Adjacent-Channel Power Measurements
For all channel and adjacent-channel power measurements a specified channel configuration is
assumed which is for instance based on a specific radiocommunication system.
This configuration is defined by the nominal channel frequency (= center frequency of the R&S ESCI if
only one carrier is active), the channel bandwidth, the channel spacing, the adjacent-channel bandwidth
and the adjacent-channel spacing. The R&S ESCI is able to simultaneously measure the power in up to
four transmission channels and up to three adjacent channels (18 channels: 12 transmission channels,
3 lower and 3 upper adjacent channels).
It offers two methods for channel and adjacent-channel power measurement:
• The integrated bandwidth method (IBW method), i.e. the integration of trace pixels within the
bandwidth of the channel to be measured to the total power of the channel,
• The measurement in time domain (Fast ACP) by means of steep resolution filters simulating the
channel.
The two measurements yield the same results. The measurement in time domain can be performed
much faster since the complete signal is measured within a channel at the same time. With the IBW
method, the channel is divided into subspectra. This is done by means of a bandwidth which is small
compared to the channel bandwidth. These subspectra are then combined by integration of the trace
pixels.
With the IBW method, the transmission channels or adjacent channels are marked by vertical lines at a
distance of half the channel bandwidth to the left and to the right of the corresponding channel center
frequency(see Fig. 4-14).
With the time-domain method, the power versus time is shown for each channel. The boundaries of the
channels are marked by vertical lines (see Fig. 4-15).
For both methods, the results are listed in tables in the lower half of the screen.
The R&S ESCI offers predefined standard settings which can be selected from a table for the common
mobile radio standards. Thus, channel configuration is performed automatically without the need to
enter the corresponding parameters manually.
For some standards, the channel power and the adjacent-channel power are to be weighted by means
of a root-raised cosine filter corresponding to a receive filter. This type of filtering is switched on
automatically for both methods on selecting the standard (e.g. NADC, TETRA or 3GPP W-CDMA).
Fig. 4-14 Screen display of adjacent-channel power measurement using the IBW method
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