08-06-2012, 03:35 PM
Simulation of MIMO Antenna Systems in Simulink
and Embedded Matlab
Embedded Matlab.pdf (Size: 649.59 KB / Downloads: 9)
Abstract
Multi-Input Multi-Output (MIMO) has emerged as
a hot topic in wireless communications during the last decade.
This is due to possible dramatic increases in reliability and
capacity as compared to single-antenna solutions. However, much
of the existing theoretical results are based on very simplistic
models of the antennas and transciever circuitry.
INTRODUCTION
Today, hardly any hardware of some complexity is built
without first performing extensive computer simulations. Communication
and radar systems involving antennas is no exception.
However, in almost all cases a communication (or
radar) system is simulated with very crude models of the
hardware and underlying physics. In contrast, the hardware
(e.g. antennas) design is based on detailed electromagnetic
simulation, but not taking the system aspects into account. The
purpose of this paper is to describe some steps in bridging the
gaps between system and hardware level simulation, based on
Matlab and Simulink. The goal is to be able to directly see
the effect of component design, or architecture, on systemlevel
performance measures.
IMPLEMENTATION OF MIMO COMMUNICATION
CHANNELS
The interaction between transmitting and receiving MIMO
antennas is described by a transfer function which takes into
account the radiation properties of the antennas and the propagation
properties of the environment. In Figure 2, the basic
steps needed to use models for the MIMO communication
channel are illustrated.
ANTENNA AND MATCHING NETWORK
This part of the system contains all components that are represented
by physical models in terms of scattering parameters
[8]. This description is used to quantify the distributed nature
of microwave components, which means that for example the
phase of a signal is not the same everywhere on a transmission
line. At lower frequencies this effect is usually ignored. The
effect is most commonly modelled in the frequency domain,
using travelling waves.