Curriculum Vitae Sander Wahls - Princeton University

Curriculum Vitae
Sander Wahls
Contact Information
Princeton University
Department of Electrical Engineering
B311 Engineering Quadrangle
Olden Street, Princeton, NJ 08544
wahls@princeton.edu
http://www.princeton.edu/~wahls
Research Areas
Signal processing, communications, machine learning, control
Current Research Interests
Machine learning methods for link adaptation
Nonlinear Fourier analysis
Education
Doctorate in electrical engineering (Dr.-Ing.)
Technische Universität Berlin, Berlin, Germany, Nov. 2011
Thesis: “Causality Constraints in Discrete-Time Filtering”
Referees: Prof. Thomas Sikora, Prof. Holger Boche
Grade: Summa cum laude
Diploma in mathematics (Dipl.-Math.)
Technische Universität Berlin, Berlin, Germany, Dec. 2007
Thesis: “A Minimum Norm Solution to the Operator Corona Problem and its
Application to MIMO-ISI Channel Equalization”
Referees: Prof. Volker Mehrmann, Prof. Holger Boche
Grade: Very good (1.1)
Academic Positions
Postdoctoral Research Fellow
Princeton University, Princeton, NJ, USA, Since Apr. 2012
Group of Prof. H. Vincent Poor
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Research Assistant
Technische Universität München, Munich, Germany, Oct. 2010 – Mar. 2012
Chair of Theoretical Information Technology (Prof. Holger Boche)
Technische Universität Berlin, Berlin, Germany, Jan. 2008 – Sep. 2010
Chair of Theoretical Information Technology and Information Theory (Prof.
Holger Boche)
Visiting Researcher
Fraunhofer Institut f. Nachrichtentechnik (HHI), Berlin, Germany, Feb. 2008 – Mar. 2012
Wireless Communication and Networks (Dr. Thomas Haustein)
Student Assistant
Grants
Fraunhofer Institut für Nachrichtentechnik (HHI), Berlin, Germany, Jun. 2005 – Dec. 2007
Broadband Mobile Networks (Prof. Holger Boche)
Two-year research fellowship of the German Research Foundation (2012-2014)
Publications
Thesis
1. S. Wahls, Causality Constraints in Discrete-Time Filter Design. Doctoral Thesis, Technische
Universität Berlin, Berlin, Germany, Oct. 2011. http://opus.kobv.de/
tuberlin/volltexte/2011/3259/
Book Chapters
2. V. Jungnickel, A. Forck, S. Jaeckel, S. Wahls, L. Thiele, T. Haustein, W. Zirwas, H.
Droste, and G. Kadel: ”Realtime implementation and field trials for downlink CoMP,”
in Coordinated Multi-Point in Mobile Communications, P. Marsch, G. Fettweis,
Eds., Cambridge University Press, 2011, ch. 13.3, pp. 331–353.
3. A. Forck, T. Haustein, V. Jungnickel, V. Venkatkumar, S. Wahls, T. Wirth, and
E. Schulz, “Early real-time experiments and field-trial measurements with 3GPP-LTE
air interface implemented on reconfigurable hardware platform,” in Long Term Evolution:
3GPP LTE Radio and Cellular Technology, B. Furht and S. A. Ahson, Eds.,
CRC Press, 2009, ch. 11, pp. 365–411.
Journal Articles
4. S. Wahls and H. Boche, ”Realizable spatio-temporal Tomlinson-Harashima precoders:
Theory and fast computation,” IEEE Transactions on Signal Processing, vol. 60, no.
9, pp. 4819–4833, Sep. 2012, doi: 10.1109/TSP.2012.2203123.
5. S. Wahls and H. Boche, ”Lower bounds on the infima in some H∞ optimization problems,”
IEEE Transactions on Automatic Control, vol. 57, no. 3, pp. 788–793, Mar.
2012, doi: 10.1109/TAC.2011.2168913.
6. S. Wahls and H. Boche, “Novel system inversion algorithm with application to oversampled
perfect reconstruction filter banks,” IEEE Transactions on Signal Processing,
vol. 58, no. 6, pp. 3008–3016, Jun. 2010, doi: 10.1109/TSP.2010.2044606.
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7. S. Wahls, H. Boche, and V. Pohl, “Zero-forcing precoding for frequency selective MIMO
channels with H ∞ criterion and causality constraint,” Signal Processing, vol. 89, no.
9, pp. 1754–1761, Sep. 2009, doi: 10.1016/j.sigpro.2009.03.010.
Conference Proceedings
8. S. Wahls and H. Boche, “A projection approach to adaptive IFIR filtering,” in Proc.
IEEE International Conference on Acoustics, Speech, and Signal Processing
(ICASSP) [USB only], Kyoto, Japan, Mar. 2012, Paper 1061.
9. S. Wahls and H. Boche, “On spatio-temporal Tomlinsom Harashima precoding in IIR
channels: MMSE solution, properties, and fast computation,” in Proc. IEEE International
Conference on Acoustics, Speech, and Signal Processing (ICASSP), Prague,
Czech Republic, May 2011, doi: 10.1109/ICASSP.2011.5946714.
10. S. Wahls and H. Boche, “Linear IIR-MMSE precoding for frequency selective MIMO
channels,” in Proc. IEEE International Conference on Acoustics, Speech,
and Signal Processing (ICASSP), Prague, Czech Republic, May 2011, doi:
10.1109/ICASSP.2011.5946718.
11. S. Wahls and H. Boche, “Design of optimal feedback filters with guaranteed closedloop
stability for oversampled noise-shaping subband quantizers,” in Proc. IEEE
Conference on Decision and Control (CDC), Atlanta, GA, Dec. 2010, doi:
10.1109/CDC.2010.5717671.
12. V. Jungnickel, A. Forck, S. Jaeckel, F. Bauermeister, S. Schiffermüller, S. Schubert,
S. Wahls, L. Thiele, T. Haustein, H. Droste, and G. Kadel, “Field trials using
coordinated multi-point transmission in the downlink,” in Proc. 3rd International
Workshop on Wireless Distributed Networks, held in conjunction with IEEE
PIMRC 2010, Istanbul, Turkey, Sep. 2010, doi: 10.1109/PIMRCW.2010.5670408.
13. S. Wahls and H. Boche, “Effcient computation of the realizable MIMO DFE,” in Proc.
IEEE International Conference on Acoustics, Speech, and Signal Processing
(ICASSP), Dallas, USA, Mar. 2010, doi: 10.1109/ICASSP.2010.5496048.
14. S. Wahls and H. Boche, “Suffcient condition for invertibility of square FIR MIMO systems,”
in Proc. IEEE International Conference on Acoustics, Speech, and Signal
Processing (ICASSP), Dallas, USA, Mar. 2010, doi: 10.1109/ICASSP.2010.5495876.
15. S. Wahls and H. Boche, “Novel characterization of the infimum in H∞ full information
control of discrete-time plants,” in Proc. Combined IEEE Conference on Decision
and Control (CDC) / Chinese Control Conference (CCC), Shanghai, China, Dec.
2009, doi: 10.1109/CDC.2009.5400571.
16. V. Jungnickel, L. Thiele, T. Wirth, T. Haustein, S. Schiffermüller, A. Forck, S.
Wahls, S. Jaeckel, S. Schubert, C. Juchems, F. Luhn, R. Zavrtak, H. Droste, G.
Kadel, W. Kreher, J. Mueller, W. Stoermer, and G. Wannemacher, “Coordinated
multipoint trials in the downlink,” in Proc. 5th IEEE Broadband Wireless Access
Workshop (BWAWS), co-located with IEEE GLOBECOM 2009, Honolulu, Hawai,
Nov. 2009, doi: 10.1109/GLOCOMW.2009.5360722.
17. S. Wahls and H. Boche, “Realizable equalizers for frequency selective MIMO channels
with cochannel interference,” in Proc. IEEE International Conference on Acoustics,
Speech, and Signal Processing (ICASSP), Taipei, Taiwan, Apr. 2009, doi:
10.1109/ICASSP.2009.4960171.
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18. S. Wahls and H. Boche, “Impact of dimension on causal equalization of the MIMO
two-tap channel,” in Proc. International Symposium on Information Theory
and its Applications (ISITA), Auckland, New Zealand, Dec. 2008, doi:
10.1109/ISITA.2008.4895583.
19. T. Haustein, V. Venkatkumar, J. Eichinger, E. Schulz, T. Wirth, V. Jungnickel,
A. Forck, S. Wahls, C. Juchems, F. Luhn, and R. Zavrtak, “Measurements of multiantenna
gains using a 3GPP-LTE air interface in typical indoor and outdoor scenarios,”
in Proc. European Wireless (EW), Prague, Czech Republic, Jun. 2008, doi:
10.1109/EW.2008.4623926.
20. T. Wirth, V. Jungnickel, A. Forck, S. Wahls, H. Gaebler, T. Haustein, J. Eichinger,
D. Monge, E. Schulz, C. Juchems, F. Luhn, and R. Zavrtak, “Realtime multiuser
multi-antenna downlink measurements,” in Proc. IEEE Wireless Communications
and Networking Conference (WCNC), Las Vegas, USA, Mar. 2008, doi:
10.1109/WCNC.2008.239.
21. T. Wirth, V. Jungnickel, A. Forck, S. Wahls, V. Venkatkumar, T. Haustein, and
H. Wu, “Polarization dependent MIMO gains on multiuser downlink OFDMA with a
3GPP LTE air interface in typical urban outdoor scenarios,” in Proc. International
ITG/IEEE Workshop on Smart Antennas (WSA), Darmstadt, Germany, Feb. 2008,
doi: 10.1109/WSA.2008.4475552.
22. V. Venkatkumar, T. Haustein, H. Wu, E. Schulz, T. Wirth, A. Forck, S. Wahls,
and V. Jungnickel, “Field trial results on multi-user MIMO downlink OFDMA in typical
outdoor scenario using proportional fair scheduling,” in Proc. International ITG
Workshop on Smart Antennas (WSA), Darmstadt, Germany, Feb. 2008, doi:
10.1109/WSA.2008.4475537.
23. T. Haustein, J. Eichinger, W. Zirwas, E. Schulz, A. Forck, H. Gäbler, V. Jungnickel,
S. Wahls, C. Juchems, F. Luhn, and R. Zavrtak, “MIMO-OFDM for a cellular deployment
- concepts, real-time implementation and measurements towards 3GPP-LTE,” in
Proc. European Signal Processing Conference (EUSIPCO), Poznan, Poland, Sep.
2007, invited.
24. V. Jungnickel, M. Schellmann, A. Forck, H. Gäbler, S. Wahls, A. Ibing, K.
Manolakis, T. Haustein, W. Zirwas, J. Eichinger, E. Schulz, C. Juchems, F. Luhn,
and R. Zavrtak, “Demonstration of virtual MIMO in the uplink,” in IET Smart Antennas
and Cooperative Communications Seminar, London, UK, Oct. 2007, invited.
25. S. Wahls and H. Boche, “Stable and causal LTI-precoders and equalizers for MIMO-
ISI channels with optimal robustness properties,” in Proc. International ITG/IEEE
Workshop on Smart Antennas (WSA), Vienna, Austria, Feb. 2007.
Software
Linear System Inversion Toolbox
A Scilab toolbox for optimal stable left-inversion of linear time-invariant systems.
The toolbox is available at http://atoms.scilab.org/toolboxes/lsitbx.
Factorization of Structured Matrices Toolbox
A Scilab toolbox for the fast factorization of matrices with displacement structure.
The toolbox is available at http://atoms.scilab.org/toolboxes/fsmtbx.
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DSP Algorithms
Service
I have implemented several algorithms (channel estimation, channel equalization,
phase tracking, link adaptation, scheduling, etc.) on Texas Instruments
6713 DSPs for a real-time wireless MIMO-OFDM testbed. The algorithms have
been used in the following demonstrations.
(2006, Dec.) Premiere in Asia: Siemens live demo shows what future mobile networks
can do. Press Release, Siemens Networks. [Online]. Available: http:
//www.siemens.cz/siemjet/en/home/ic/enterpriseNetworks/press/releases/
archive/Main$pageletManager$PressList$AssetGrid-gotoItem/37893.jet
(2007, May) Researchers at Nokia Siemens Networks double the capacity in uplink using
virtual MIMO in LTE networks. Press Release, Nokia Siemens Networks. [Online].
Available: http://www.nokiasiemensnetworks.com/press/press-releases/
researchers-at-nsn-double-the-capacity-in-uplink-using-virtual-mimo
(2007, Dec.) Up to ten times faster mobile broadband data rates a step closer
to reality. Press Release, Nokia Siemens Networks. [Online]. Available:
http://www.nokiasiemensnetworks.com/press/press-releases/
ten-times-faster-mobile-broadband-data-rates-step-closer-reality
(2008, Dec.) Nokia Siemens Networks peers into the ultra-fast future with groundbreaking
mobile broadband demonstration. Press Release, Nokia Siemens Networks.
[Online]. Available: http://w3.nokiasiemensnetworks.com/cn/Press/Press+
releases/news-archive/Nokia+Siemens+Networks+peers+into+the+ultra-fast+
future.htm
(2009, Jul.) System for increasing capacity in future mobile communications
networks successfully tested. Press Release, Deutsche Telekom. [Online].
Available: http://www.laboratories.telekom.com/public/English/Newsroom/
news/Pages/Verfahren-zur-Kapazitaetserhoehung-in-Mobilfunknetzen.aspx
(2009) LTE performance for initial deployments. White Paper, Nokia Siemens Networks.
[Online]. Available: http://www.nokiasiemensnetworks.com/sites/
default/files/document/LTE_measurement_A4_1302.pdf
TPC Member
Reviewer
Global Wireless Summit (GWS) 2013
IEEE Transactions on Signal Processing 2009, 2010, 2011, 2012
International Symposium on Wireless Communication Systems (ISWCS) 2011,
2012
International Conference on Methods and Models in Automation and Control
(MMAR) 2012
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Memberships
IEEE, since 2009
IEEE Signal Processing Society, since 2011
VDE-ITG, since 2012
GAMM Activity Group ”Mathematical Signal and Image Processing”, since 2012
Last Update
11/27/12
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