All of
the MIMO-specific measurements are based on the full bandwidth and can be
applied to 4x2 and 2x2 MIMO systems. The output is based on the channel
H-matrix with complex values, mean amplitude and phase. From the channel
matrix, a singular-value decomposition is calculated. The result, the singular
value, is used to obtain the condition number, which qualifies whether the
channel is “ill-conditioned” (no MIMO applicable) or “well-conditioned” (MIMO
usable).
The R&S®ROMES drive test software and R&S®TSMW universal radio network analyzer can
be used for LTE-MIMO-specific measurements in 4x2 and 2x2 MIMO antenna systems.
The software can capture the real-world scenario to validate MIMO performance
for FDD (TD-LTE H1 2012).
The measurements are based on the
H-channel matrix, which is calculated per cell and per resource block. This
enables further drill-down to determine factors such as interference, multipath
fading, antenna correlation and noise in relation to their spectral position.
All the data can be exported into ASCII
and XML. This enables third-party tools for fading emulation to use the Rohde
& Schwarz MIMO drive test solution to reproduce the MIMO channel in the
lab.
Benefits of the
LTE-MIMO feature
·
Determining in what areas MIMO can be
profitably used
·
Determining whether additional
investments for MIMO will pay off
·
Optimizing MIMO performance
·
Reproducing LTE signal channels in the
lab under real-world conditions
How to upgrade an existing R&S®TSMW
universal radio network analyzer
The MIMO feature requires R&S®ROMES
4.65 and the R&S®TSMW-K30 MIMO option. The R&S®TSMW option requires
also the R&S®TSMW-K29 LTE option and a second receiver (R&S®TSMW-K71
must not be active). For MIMO measurements it is strongly recommended to use a
MIMO antenna such as the R&S®TSMW-Z7 (700 MHz) or R&S®TSMW-Z8
(multiband) to obtain comparable measurements, since MIMO performance strongly
depends on the antenna design.