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CATEGORIES:Signal Processing and Communications Lab Seminars
SUMMARY:Filter Design with Secrecy Constraints - Dr Miguel
R. D. Rodrigues\, University of Porto
DTSTART;TZID=Europe/London:20090225T141500
DTEND;TZID=Europe/London:20090225T151500
UID:TALK16943AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/16943
DESCRIPTION:The issues of privacy and security in wireless com
munication networks have taken on an increasingly
important role as these networks continue to flour
ish worldwide. Traditionally\, security is viewed
as an independent feature with little or no relati
on to the remaining data communication tasks and\,
therefore\, state-of-the-art cryptographic algor
ithms are insensitive to the physical nature of th
e wireless medium.\nThis talk introduces yet anoth
er physical-layer security paradigm\, based on an
estimation-theoretic problem formulation rather th
an the information-theoretic one: We consider the
problem of filter design with secrecy constraints
in the classical wiretap scenario\, where two legi
timate parties communicate in the presence of an e
avesdropper. In particular\, we consider the desig
n of transmit and receive filters that minimize th
e mean-squared error (MSE) between the legitimate
parties whilst guaranteeing a certain eavesdropper
MSE level subject to a total average power constr
aint\, in the situation where the main channel and
the wiretap channel consist of a bank of parallel
independent degraded Gaussian channels (a scenari
o representative of orthogonal frequency division
multiplexing (OFDM) communications systems).\nThe
traditional problem of filter design for point-to-
point communications systems can be easily cast in
to the framework of convex optimization theory by
using standard tools from majorization theory or m
atrix-monotone functions. In contrast\, the proble
m of filter design with secrecy constraints is muc
h more complex. We address this problem by putting
forth a novel mathematical framework\, revolving
around the notions of D-sets\, D-functions and D-o
ptimization problems\, that enables the transforma
tion of the original optimization problem into a c
onvex one. We derive the form of the optimal recei
ve filter and the optimal transmit filter. We also
derive the form of the optimal filters in the asy
mptotic regimes of low and high available power. W
e will complement theoretical insight with various
numerical results. \nThis represents joint work w
ith João Xavier from the Technical University of L
isbon\, Portugal.\n\n
LOCATION:LR5\, Engineering\, Department of
CONTACT:Rachel Fogg
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