Mimo (Multi Input Multi Output) Concepts - Keysight X Series Manual

Concepts

MIMO (Multi Input Multi Output) Concepts

MIMO (Multi Input Multi Output) Concepts
Multiple antenna techniques take advantage of spatial diversity in the radio
channel. Multiple antenna techniques are of three main types: diversity, MIMO,
and beamforming, to improve signal robustness and to increase system
capacity and single-user data rates.
Figure 3-10
simplest to the most complex, indicating how the radio channel is accessed by
the system's transmitters and receivers.
Figure 3-10 MIMO Radio-Channel Access Modes
Transmit
antennas
SISO - The most basic radio channel access mode is single input single output
(SISO), in which only one transmit antenna and one receive antenna are used.
This is the form of communications that has been the default since radio began
and is the baseline against which all the multiple antenna techniques are
compared.
MISO - Slightly more complex than SISO is multiple input single output (MISO)
mode, which uses two or more transmitters and one receiver.
SIMO - The third mode shown in
(SIMO), which—in contrast to MISO—uses one transmitter and two or more
receivers.
MIMO - The final mode is full MIMO, which requires two or more transmitters
and two or more receivers. This mode is not just a superposition of SIMO and
MISO since multiple data streams are now transmitted simultaneously in the
same frequency and time, taking full advantage of the different paths in the
radio channel. For a system to be described as MIMO, it must have at least as
Keysight WLAN Measurement Guide
illustrates the range of possible antenna techniques from the
Receive
The radio channel
antennas
SISO
MISO
SIMO
MIMO
Figure 3-10 is single input multiple output
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