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R&S FSH
Digital Modulation Analyzer
Measurements on LTE Signals
Operating Manual 1173.6275.12 - 30
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9.8.6.8 Configuring EVM Results
In case of the EVM, you can define the unit of the EVM and EVM calculation method.
To obtain EVM values according to standard, the channel estimation and EVM
windowing methods defined in 3GPP TS 36.141 are used. Prerequisites for a standard
compliant measurement are signals according to the enhanced test models defined in
36.141 and an external frequency reference delivered via the Ref In connector or via
GPS. The EVM according to standard measurement is mainly useful for high accuracy
signal quality measurements with cable-connected eNodeB antenna ports. The
measurement takes longer but the EVM value incorporates more signal errors like
inter-symbol-interference.
If the EVM is not measured with the “EVM According to Standard” option enabled,
optimum channel estimation and EVM calculation methods are used. Especially for
over-the-air measurements this setting is useful since influences of the air interface like
inter-symbol-interference are compensated. Additionally this mode is faster.
Selecting the unit of the EVM
► Press the MEAS key.
► Press the "Display Settings" softkey.
► Select either the "%" or "dB" menu item.
The R&S FSH shows the EVM in the unit you have selected.
Displaying the EVM according to standard
► Press the MEAS key.
► Press the "Meas Settings" softkey.
► Select the "EVM According to Standard" menu item.
If the R&S FSH displays the EVM according to standard, the menu item is marked
by an [X].
9.8.6.9 Configuring Component Carriers
When you are performing measurements on systems with carrier aggregation, the
R&S FSH allows you to define several characteristics for each component carrier.
Selecting the number of component carriers
The R&S FSH supports measurements on up to five component carriers.
► Press the MEAS key.
► Press the "Meas Settings" softkey.
► Select the "Number of Carriers" menu item.
The R&S FSH opens an input field to select the number of component carriers.