Investigations into multiple-element antenna systems for wireless communications.
Speaker: Konstanty Bialkowski, ITEE
When: 2005-04-21 13:00:00
Venue: 50-S201
Host: Adam Postula
Abstract:The ever increasing demand for higher data rates is common to
all communication systems. In mobile communication systems this is no
different, and expectations have risen so that the quality of service
needs to equal or exceed that of wire based communication systems. This
expectations provides a challenge as in the wireless domain, there is
finite bandwidth available. In addition, the quality of signal
transmission in wireless communications is adversely affected by
multipath propagation and interference due to the presence of other
users in the system.
There have been many methods proposed in order to help mitigate these
problems. Systems such as spread spectrum techniques (FHSS, DSSS),
orthogonal frequency division multiplexing (OFDM), Ultra-wide band
(UWB) are some examples of such methods. In addition to these there are
also methods which involve adaptive antennas. Adaptive antennas usually
feature multiple elements and as such are called Multiple Elements
Antennas (MEA). MEAs can be used to compliment these other methods.
Multiple-Input Multiple-Output (MIMO) systems are a type of MEA system,
which makes use of multi-path propagation to form multiple channels
between transmitter and receiver. These channels can be used in two
ways: via spatial multiplexing (capacity is increased), or via spatial
diversity (data rate is fixed, but a given quality of service is
guaranteed). For MIMO systems, it has been shown that capacity
increases as a linear function of the number of antennas used.
The aim of this research is to investigate and develop MEA systems, and
specifically MIMO systems. Both theoretical and experimental
investigations will be performed. The theoretical work will concern
development and testing of various scattering models which can be used
for assessing capacity of MIMO systems. The experimental work will
concern the two platforms, a simple space and polarization diversity
system, as well as a full MIMO system. The diversity system will make
use of Bluetooth modules for the RF subsystem. The MIMO testbed will
initially feature a FPGA with a soft-core processor running uCLinux,
and two high speed Analogue-to-Digital input and Digital-to-Analogue
output channels. This testbed will be able to perform experiments based
on 2x2 MIMO. The experimental results will be used to refine and verify
theoretical models currently being used to predict the performance of
various coding schemes as well as transmitter and receiver antenna
configuration.
The importance of investigating MIMO systems is that they are being
proposed for stems are being proposed in order to meet the data rate
requirements in next generation wireless networks, such as 802.11n and
the fourth generation of mobile phone systems. Other applications of
MIMO can concern the areas of imaging, wireless sensors and wireless
power transmission.
Biography:Konstanty Bialkowski received his Bachelor of Electrical Engineering
(Honours I) / Bachelor of Science (Computer Science) degrees in 2003 at
the University of Queensland.
He is currently undertaking a PhD program under the supervision of Dr.
Adam Postula. His research interests include MIMO systems, wireless
communications and Linux.
Type: Ph.D confirmation
Contact:Adam Postula, seminar host (adam@itee.uq.edu.au)
or Guido Governatori (ITEE seminar co-ordinator)
(guido@itee.uq.edu.au)