Rohde & Schwarz R&S AMS32-K31, Руководство пользователя

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Noise-Limited OTA Performance in Transmit Diversity Mode
R&S
®
AMS32-K31
11 User Manual 1175.6678.02 ─ 01
2.1.2.2 Communication Settings
The R&S CMW500 LTE driver provides a configuration dialog for the basic properties of
the LTE downlink signal of the R&S CMW500 ("Cell Setup" and "Connection" settings).
Access: "Communication Settings" button in the "OTA Auto Test Template" dialog; see
​
figure 2-4 .
The contents of the driver configuration dialog depend on the radio technology. For LTE
MIMO OTA tests, you can open the "Cell Setup" tab in order to select the bandwidth and
modify the DL and UL power settings. Check "Setup Cell Parameters" to transfer your
settings to the R&S CMW500.
Downlink levels for MIMO sensitivity tests
The RS EPRE (energy per resource element of the reference signal) defines all downlink
physical channel levels of the R&S CMW500. A sensitivity measurement involves repea-
ted BLER measurements at variable RS EPRE settings. The sensitivity threshold, i.e. the
RS EPRE at which the BLER crosses the 10% threshold, is returned as the basic mea-
surement result.
The RS EPRE setting in the driver configuration dialog merely serves as a start value for
the sensitivity measurement; the complete sequence of RS EPRE values measured is
logged in a file
LteMimoData.csv
; see
​
figure 2-7 . An RS EPRE setting close to the
sensitivity threshold can accelerate the measurement.
R&S AMS32 allows you to modify the specified 10 % value for the BLER threshold; see
​
chapter 2.1.2.3, "Measurement Settings" , on page 12. See also "Normalization of sen-
sitivity threshold levels" in
​
chapter 2.3, "Result Evaluation and Reporting" ,
on page 16.
Configuration