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Technology that arises out of the laboratory's research is
available for industrial applications. Some of the laboratories
technologies available from the laboratory are highlighted
below; for additional examples, contact the laboratory. All
such technologies can be freely used for noncommercial purposes.
If you are interested in licensing any for commercial purposes,
please contact either:
Featured Technology
Quantization Index Modulation
(QIM) | Download QIM reference
code:
In recent years, there have been a growing realm of applications
that require one to embed digital information into some host
signal, which may be inherently analog or digital and which
is generally not known at the decoder. There is a fundamental
tradeoff between the number of bits embedded, the distortion
incurred by the embedding process on the host signal, and
the robustness with which the bits are embedded. Good information
embedding systems make these tradeoffs efficiently. Spread-spectrum
systems are examples of information embedding systems that
are not efficient, except when the host signal is known at
the decoder. Quantization Index Modulation (QIM) systems,
by contrast, do achieve the fundamental performance limits
in many practical scenarios of interest, particularly when
combined with a technique referred to as distortion-compensation
(DC-QIM) and error control coding (coded DC-QIM). Moreover,
QIM systems can be implemented in a computationally very efficient
manner.
At one end of a spectrum, applications of QIM and its variants
include digital watermarking, data hiding and covert communication.
At the other end of the spectrum, there provide important
solutions to problems of backwards-compatible upgrading of
existing analog and digital communications infrastructure,
and efficient multiplexing of transmissions to different users
in multiple-antenna wireless systems.
More information on QIM and its applications can be found
in several of the papers and patents listed in the publications
section of the web site. Those interested in experimenting
with QIM in some application of interest can click on the
link below to download the public QIM reference code we are
making available below, which can serve as a useful starting
point for more sophisticated implementations.
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