Research highlights

1
Research highlights

• Framework for Traffic Analysis in Wireless
  Networks, first exact solution for outage in
  cellular networks
• 1st paper on MC-CDMA
• ICI mitigation in mobile OFDM
• New Attacks on Watermarking
• Detection theory applied to watermarking
• Privacy in Biometrics

2
Research Highlight 1991 Framework for Traffic
Analysis in Wireless Networks

• Mathematical framework based on Laplace
  Transforms for the analysis of random access
  schemes (MAC ) for wireless networks (considering
  PHY)
• Basic idea
• Rayleigh fading gives exponential pdf of power
• Average performance Laplace performance
  channel
• Interference power sum of power of individual
  components
• Average performance
• Visibility, Impact, Results
• Vederprijs 1992, MSc Cum laude, PhD cum laude
• Monograph published by Artech House (their 2nd
  book on Wireless)
• More than 119 citations ( 34 33 17 15 14
  10 ..)
• Virtual Cellular Network in Chinese cellular
  proposal

3
Research Highlight 1993 1st paper on MC-CDMA

• Basic idea
• cascade CDMA and OFDM, or equivalently,
• define spreading codes in the frequency domain
• Advantages in simultaneous user separation in
  multipath channels

• Impact
• Name and concept MC-CDMA proposed first in 1993
  paper
• Citations 405 37 38 26 20
• MC-CDMA has become a major research topic (85,300
  Google hits)
• MC-CDMA proposed in several standards (ETSI, IEEE
  802)

Credit also to Gerhard Fettweis
4
Research Highlight 2002 - 2004 ICI mitigation
in mobile OFDM

• Basic idea
• series expansion of temporal behavior of
  subcarriers allows simple modeling of Inter
  Carrier Interference
• Extension of statistical propagation model
  behavior for derivatives
• Impact, Visibility
• 2 IEEE Transactions papers (2004)
• patent applications
• Basis for solution implemented in two ICs
• 15 10 8 citations

MMSE ICI canceller
Conventional OFDM
Credit also to Stan Baggen et al.
5
Research Highlight 1997 Detection theory
applied to watermarking

• The basic idea
• Watermarking is equivalent to the detection of
  weak signals in the presence of structure
  interference
• Hollywood content is not AWGN ?
• Exploit structure (predictability) in the content
• Impact
• Papers, 60 19 15 .. citations
• Basic patent granted on predictive filtering for
  WM detection
• Applied in Watercast product
• you have seen content with our invisible
  watermarks, which are detected 24/24 on 1000 tv
  stations, using algorithms based on this idea

Credit also to Ton Kalker
6
Research Highlight 1998 New Attacks on
Watermarking

• Basic Idea
• robustness of watermark requires contiguous
  decision regions, whereas confidentiality of the
  key would require scattered chaotic regions
• Search for point on the decision threshold of
  WM detector
• Then evaluate sensitivity to small perturbations,
  say, dimension by dimension
• This strongly suggests the Conjecture
• Public-key watermarking can not exist
• Impact
• Patented countermeasures
• IEEE Proceedings paper and IHW
• Citations 150 71 62 38

7
Research Highlight 2002 Privacy in Biometrics

• The issue with conventional biometry
• Biometric template data can be misused by
  dishonest verifiers
• Someone who finds your passport can misuse your
  fingerprint
• How to set up a public data base for biometric
  verification?
• Basic idea
• One-way functions (cf. password protection) can
  be used if(f!) biometric measurements are
  preconditioned by helper data
• Information theoretic proof that helper data
  reveal less than e, that is, I(WX) lt e ? 0)
• Helper date does not need to affect reliability
  (FAR FRR)

• Impact
• leading theme for 10 fte project now at Philips
  Research, and project at universities.
• Potential impact passports that contain
  verification data for biometrics, without
  allowing misuse
• Privacy protection even in public database with
  dishonest verifiers of fingerprint
• Basis for PUF Research
• Citations 15 9 (since 2003)
• Tuyls, Willems effective cryptographic key
  length Shannon capacity of biometric
  measurement channel

X
F(x)
Y
G(x,w)
noise N
Helper data W
Challenge
8
Curriculum vitae Education

• Masters
• Eindhoven University of Technology, The
  Netherlands
• Ir., Cum Laude, December 1986
• PHD
• Delft University of Technology, The Netherlands
• Dr., Cum Laude, December 18, 1991
• Promoter Prof. Jens Arnbak

9
Curriculum vitae Professional experience

• Physics and Electronics Lab (FEL-TNO) radio
  propagation models for frequency and operations
  planning
• 1987-1988 Research Scientist, on military
  service (ROAG)
• Delft University of Technology Teletraffic in
  wireless networks
• 1988-1991 Universitair Docent (Asst. Prof.)
• 1994 Universitair Hoofddocent (Assoc. Prof.)
• The University of California at Berkeley
  Wireless Multimedia Communication
• 1992-1993 Assistant Professor
• 1995-1998 Adjunct Asst. Professor
• Nat.Lab. Philips Research, Eindhoven Conditional
  access, Copy management, Watermarks, Biometrics
  till 2003, Communication Systems after 2002
• 1995-1998 (Senior) Research Scientist
• 1998-2000 Principal Scientist
• 2001-now Department Head, Senior Director

10
Teaching experience

• T.U. Delft
• Transmission systems
• U.C. Berkeley
• Signal and Systems EECS 120,
• Probability Theory EECS 226, started EECS 126,
• Selected Topics in Communications EE 290i
  Wireless Communication
• Short Courses Tutorials
• U.C. Extension Wireless Communication Networks
• Philips CTT Wireless Basics Advanced wireless
  RF Transceivers CoCoSec (Security and DRM)
• EESI PATO IPA EIDMA WIC EPFL
• Coaching of students in during internships, and
  MSc, PhD, postdocs
• UC Berkeley TU Delft Philips Research
• Freelance radio presenter
• NOS, ROZ various local radio stations Internet
  webstation
• Educational CD-ROM and Internet
• Kluwer Springer