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- Smart antennas and MIMO systems |
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Speakers
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Andreas
F. Molisch, Mitsubishi Electric Research Lab,
and Lund University, Sweden; Juha Laurila,
Nokia Research Center, Helsinki, Finland; Klaus
Hugl, Nokia Research Center, Helsinki, Finland;
Ernst Bonek, Technische Universität Wien,
Austria
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Duration
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Full
Day
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Start
Time
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9h00 |
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Abstract
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Smart
antennas and MIMO (multiple-input multiple-output)
systems utilize multiple antennas at one and at
both wireless link ends, respectively. These techniques
can be used to increase the capacity of mobile radio
systems, both for upgrading second-generation systems
and for use in third- and fourth generation systems.
Thus, multi-antenna systems have attracted enormous
interest and a lot of effort has been spent for
its system development and standardization. The
tutorial will give a comprehensive overview over
all relevant aspects of smart antenna and MIMO systems.
The mobile radio channel, especially its directional
nature defined by the directions-of-arrival and
directions-of-departure of the waves propagating
from transmitter to receiver, determines the performance
of multi-antenna systems. Therefore, we start out
with an introduction of spatial channel sounding
techniques forming the basis for spatial channel
measurements and spatial channel characterization.
We present measurement results of the directional
channel properties as seen from the base station
and from the mobile terminal only, as well as measurements
of the double-directional propagation characteristics.
We then explain how these measurement results can
be utilized and included in spatial channel models,
which are required for the design and development
of adaptive antenna and MIMO systems.
Next, we describe transceiver structures and algorithms
for smart antennas at one link end. After an introduction
to the basic smart antenna technology, we describe
different adaptation techniques for multi-antenna
reception in detail. Thereby, we consider temporal
reference, spatial reference as well as blind adaptation
algorithms and present their performance in different
propagation conditions. Moreover, the fundamental
differences of reception and transmission using
several antennas will be explained and transmission
strategies including downlink beamforming and transmission
diversity will be derived. The more practical aspects
of roll-out and capacity of smart antenna base stations
- especially in the context of 3G systems - will
complete the considerations of multiple antennas
at one link end.
Next, we present the two operation modes of MIMO
systems applying multiple antennas for transmission
and reception: diversity enhancement, and BLAST-like
schemes. In the former case, the multiple antennas
at both link ends are used to provide a high degree
of diversity, resulting in a high-quality link.
We explain what diversity degree and beamforming
gain can be achieved in different types of wireless
channels. Then, we describe BLAST schemes where
independent data streams are sent from the different
transmit antennas, and the multiple receive antennas
are used to receive and separate those different
data streams. We show how the capacity of these
systems can increase linearly with the number of
transmit and receive antennas. Different BLAST implementations
are explained, and their advantages and drawbacks
are discussed. Finally, we demonstrate the principles
of space-time codes, and show how those can be applied
for diversity and capacity increase. A discussion
of interference-limited MIMO systems, and of waterfilling
schemes, will round off the presentation.
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Short
Biography of the Speaker(s):
Andreas F. Molisch received the Dipl. Ing., Dr. techn. (with
highest honors), and habilitation degrees from the Technical University
Vienna in 1990, 1994, and 1999, respectively. From 1991 to 2001,
he was with the Institut für Nachrichtentechnik und Hochfrequenztechnik
(INTHFT) of the TU Vienna, most recently as associate professor.
From 2001 to 2002, he was with AT&T Laboratories - Research; since
2002 he has been with Mitsubishi Electric Research Laboratory,
Murray Hill. He is also professor and chairholder for Radio Communications
at Lund University, Sweden His current research interests are
MIMO systems, UWB, characterization of mobile radio channels,
and wideband systems. He is senior member of the IEEE, and (co)author
of two books, five book chapters, some 50 journal papers, four
patents, and numerous conference contributions. He is also editor
for IEEE Trans. Wireless Comm., chairman of the COST273 working
group on MIMO channels, and active in the 3GPP adhoc group for
this topic.
Juha Laurila was born 1970 in Korpilahti, Finland. He received
the M.Sc. (E.E.) degree from the Helsinki University of Technology,
Finland (Institute of Radio Communications) in 1995 and the Dr.
Tech. degree from the Vienna University of Technology, Austria
(Institut fuer Nachrichtentechnik und Hochfrequenztechnik) in
2000. In his doctoral thesis he investigated semi-blind algorithms
for mobile communications concentrating on the reception with
multiple antennas at the base station. In 1995-96 he was with
the Helsinki University of Technology and from 1996 to 2000 with
the Vienna University of Technology, working as research engineer
at both universities. Since 2000 he has been working as senior
research engineer and most recently as research manager at Nokia
Research Center (Radio Communications Laboratory) Helsinki, Finland.
His current research activities are related to the utilisation
of multiple antenna techniques in cellular systems. His main interests
are in link-level algorithm development, but he is also involved
with spatial propagation studies and system-level investigations.
J. Laurila has authored or co-authored one book chapter and some
30 international reviewed journal and conference publications.
He holds one patent and several applications are pending.
Klaus Hugl was born in Mistelbach, Austria, 1974. He received
his Dipl. Ing. and Dr. techn. degrees (with highest honors) from
Technische Universität Wien (TU-Wien) in 1998 and 2002, respectively.
From 1998 to 2002, he was with the Institut für Nachrichtentechnik
und Hochfrequenztechnik (INTHF) of TU-Wien, working as a research
engineer. Since 2002, he has been with Nokia Research Center (Radio
Communications Laboratory) Helsinki, Finland. His current research
interests are adaptive antenna systems and spatial channel modeling/characterization.
He (co)-authored more than 10 international reviewed journal and
conference publications, and holds one patent in the field of
multi-antenna systems.
Ernst Bonek was born in Vienna, Austria, 1942. He received
the Dipl. Ing. and Dr. techn. degrees (with highest honors) from
the Technische Universität (TU) Wien. In 1984, he was appointed
Full Professor of Radio Frequency Engineering at the TU Wien.
His present field of interest is mobile communications at large.
Recent contributions concern the characterization of mobile radio
channels, cordless telephony, and advanced antennas and receiver
designs. Altogether, he authored or co-authored some 100 journal
publications. He holds three patents, and seven more applications
on mobile radio technology are pending. His current positions
in scientific organizations include: chairman of the "Antennas
and Propagation" working group in the European research initiative
"COST 273"; Area Editor of "Wireless Personal Communications";
Chairman of URSI (Union of radio scientists) commission Chairman
of a COST 259/260 workshop on "Spatial channel models and adaptive
antennas"; Senior Member of IEEE.
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