LTE Signaling
R&S
®
CMW-KM5xx/-KS5xx
37
User Manual 1173.9628.02 ─ 16
Scenario
TM
1)
DCI
Format
TX x RX
Antennas
Beamf.
Matrix
PMI
1)4)
Transmission Scheme
RA
1)
Type
6
1B
4x2
-
0 to 15
CL spatial multiplexing, single layer 2
1)
TM = transmission mode, PMI = precoding matrix indicator, 2CC = two component carriers, CA = carrier aggregation, RA =
resource allocation
2)
Fading not supported for 4x2 antenna configurations
3)
Output before radio channel, for example for external RF fading
4)
Depending on the scheduling type, the used PMI value is configured statically or it follows the PMI value reported by the UE
5)
Depending on the scheduling type, the transmission scheme is configured statically or it follows the RI value reported by the UE.
In the latter case, the scheme can change to transmit diversity.
6)
For scheduling type "Follow WB CQI-RI", only DCI format 2A is supported.
2.2.11.1
Radio Channel Coefficients for MIMO
A MIMO 2x2 configuration uses two transmit antennas (TX) and two receive antennas
(RX). An ideal radio channel would provide isolated connections between pairs of
antennas, so that each RX antenna receives only the signal of one TX antenna.
In practice, an ideal radio channel is not possible. A real radio channel couples the
sent signals, so that the RX antennas always receive a combination of the TX antenna
signals. This is illustrated in the following figure for MIMO 2x2, assuming that there is
only one signal path between each TX and RX antenna.
Fig. 2-15: Radio channel for MIMO 2x2
The channel amplitude and phase responses for the individual transmission paths can
be characterized by the complex coefficients h
11
to h
22
. The indices always specify the
receiver first.
In a test setup with the R&S
CMW and a UE, the radio channel is typically located
within the instrument. Each RF output connector is connected directly to one UE
antenna connector.
General Description
深圳德标仪器
135-1095-0799