Signal Processing 83 (2003) 1561–1563

www.elsevier.com/locate/sigpro

Editorial

Hans Wilhelm Sch#u%ler celebrateshis 75th birthday

Many of this journal’s readers know Hans WilhelmSch#u%ler, from his books, his other publications, or theconferences and workshops which he chaired. Manyothers may remember the papers in this journal dedi-cated to his 70th birthday. All of them (and us) willprobably feel again that it is unbelievable: Already2ve years since then? Already 10 years since he be-came an Emeritus? Already 75 years? But he is stillso active?What more can be said?Which parts of the 70th-birthday greetings in SIG-

NAL PROCESSING ’98 do need to be repeated?But, given the solemn occasion and also the assump-

tion that there are younger readers as well as thosefrom other sectors of his/our digital-signal-processing2eld, some words are appropriate, as an informa-tion about pioneering work, a reminder of importantprogress and basic results, an introduction to thisspecial issue, and a warm greeting to Hans WilhelmSch#u%ler.So, this is a brief (and probably incomplete) sum-

mary of his long and successful way:

• Born at Dortmund in February 28th, 1928• School and practical education there, at and afterthe end of World War II, becoming a technician

• Polytechnical education at Dortmund, resulting inan “Ingenieur” degree in 1951

• University education and work at RWTH Aachenin electrical engineering/communications, witha “Diplom-Ingenieur”, “Doktor-Ingenieur”, and“Habilitation” degree within 10 years altogether(showing the amazing and sometimes, for his stu-dents, frightening “Sch#u%ler speed and intensity”already at this stage!)

• Lecturer at Aachen in 1961

• Research as an Assistant Professor at Cornell Uni-versity, Ithaka, USA, in 1962

• Professor at the Technical University of Karlsruhein 1963

• Professor and founder of “the INT”, the “Institutf#ur Nachrichtentechnik” (= telecommunications in-stitute) at the newly created Faculty of Engineeringof the University of Erlangen—N#urnberg, in 1966

• Guest researcher for many times in the US (at BellLabs, MIT/Cambridge, Rice University/Houston)

• Host of many US colleagues at INT who were hisand became our friends

• Architect of a strong INT structure with hisown central group in DSP theory and realizationand sub-groups in adjacent 2elds, like “controlin communications”, “information and codingtheory”, “2-D and image processing”, “speechprocessing”—a structure with strong links andmuch freedom, which is not at all common inGerman universities

• Member and motor of many committees preparingand pushing conferences, new research areas, po-litical developments in science, research directionsin Bavaria (“Academy of Science”) or the DFG(where he was a “Senator”), etc.

• Awarded many times, by the IEEE as well asEURASIP, by VDE and ITG, by the “Eduard–RheinFoundation” as well as the German government(“Bundes-Verdienstkreuz”), by the universities ofVienna and Munich with their “Doctor honoriscausa” degrees—just to mention the last award: the“2003 IEEE Jack Kilby Signal Processing Medal”,given for “his role in the early development ofthe 2eld of digital signal processing, especially thetheory, design, and implementation of analog anddigital 2lters”

0165-1684/03/$ - see front matter ? 2003 Elsevier Science B.V. All rights reserved.doi:10.1016/S0165-1684(03)00074-4

1562 U. Heute et al. / Signal Processing 83 (2003) 1561–1563

• “Doktor-Vater” of 49 co-workers who suLered—and gained from his guide-line: “Diamonds emergeunder pressure!”

• Host to seven of them, with the necessary surround-ings, atmosphere, and freedom, to acquire their“Habilitation” (which is the “classical” way to aprofessorship, in Germany), seeing them and tenothers of his own group as well as 2ve more fromINT become professors themselves

• Participant of regular meetings of INT membersyear by year, for the exchange of thoughts andideas—and for continuing and ever deeper friend-ships.

Five years ago, a special issue of SIGNAL PRO-CESSING on echo- and noise-reduction techniquescoincided with the 70th birthday, and the guest edi-tor, Eberhard H#ansler of Darmstadt, dedicated “his”issue to Hans Sch#u%ler, in his editorial. Some of theauthors of that issue re-appear now—as some of theauthors, but also having the honour to be guest editorsthemselves.In the latter role, we should very much like to

express our gratitude to the other authors, but es-pecially also to the reviewers for accepting a toughtime schedule (so that this 2ts quite well to HansSch#u%ler’s principles, see above: : :). The authorsare:

G!unter F. Dehner(INT Ph.D. 1976, now Head of “qDSP Design

& Applications”, Erlangen) with a “tutorial and be-yond” contribution about the classical INT subjectof IIR digital-2lter design with quantized coeP-cients, including some ideas developed very re-cently and partially in contact with Hans WilhelmSch#u%ler,

Alfred Fettweis(the other pioneer in digital 2ltering in Ger-

many at the same time, with his chair at Ruhr-Universit#at Bochum, now an Emeritus at Bochum)with deep thoughts about physical and mathematicalbases of “signals claimed to be faster than light”,

Heinz G!ockler (with Heiko Kopmann)(external INT Ph.D. 1989, now Professor for Digital

Signal Processing at Ruhr-Universit#at Bochum) with

novel error models and an error analysis for wide-banddirect-conversion receivers,

Ulrich Heute (with Th. G#ulzow and Th. Ludwig)(INT Ph.D. 1975, now Chair for Circuit & Sys-

tem Theory at the University of Kiel) with newvariable-rate and variable-bandwidth spectral-subtrac-tion noise reduction techniques,

Johannes Huber (with R. Fisher and Christoph Wind-passinger)(formerly one of the co-leaders of INT, now Chair

for Information Transmission at the University ofErlangen) with an overview and novel framework fordecision-feedback equalizers,

Karl Dirk Kammeyer (with D. W#ubben)(INT Ph.D. 1977, now Chair for Telecommuni-

cations at the University of Bremen) with a sur-vey and extensions of equalization techniques forMIMO systems under frequency-selective fadingconditions,

Sanjit K. Mitra (with St. Franz and G. Doblinger)(INT Humboldt guest researcher 1975 and several

times later, Chair for Signal and Image Processing,University of California, Santa Barbara) with ideasabout the application of the “warped DFT” to the de-tection of spectral lines in noise,

Rudolf Rabenstein (with L. Trautmann)(INT Ph.D. 1991, now a Senior Engineer and

“Privat-Dozent” at INT Erlangen) with results ofthe application of functional transforms to musicsynthesis,

Ivan Selesnick and Sidney Burrus (with F. Fernandesand C. van Spaendonck)(both INT guest researchers in 1997 and 1976, re-

spectively, where Humboldt-guest S. Burrus becamealmost a “permanent INT member” due to manylonger stays; both professors in the US, at BrooklynPolytechnic and Rice Univerity, respectively) with aninvestigation on allpass-based complex wavelet de-signs using allpass systems with minimax phase error,

Peter Vary (with P. Jax)(INT Ph.D. 1978, now Chair for Communica-

tion Devices at RWTH Aachen) with a paper on

U. Heute et al. / Signal Processing 83 (2003) 1561–1563 1563

improved synthetic creation of wideband speech fromtelephone-band signals.

From the guest-editorial team to Hans WilhelmSch#u%ler as well as to his wife, Helga Sch#u%ler (whois a professor, too, and “at least as active” accordingto her husband):

Congratulations, and all the best for the future!

Ulrich HeuteKarl Dirk Kammeyer

Peter Vary