Codes on Graphs: Past, Present and Future


Event Speaker: 

G. David Forney, MIT

Event Location: 


Event Date/Time: 

Tuesday, October 23, 2012 - 4:00pm

Reception to follow.
The subject of codes on graphs began with convolutional codes and trellis diagrams, and continued with tail-biting trellis realizations and low-density parity-check (LDPC) codes on Tanner graphs.  In the past decade, the beginnings of a general theory of graphical realizations of linear and group codes has been developed. Cycle-free graph realizations are special, and are well understood.  Trellis realizations are also quite special, and are fairly well understood, even in the cyclic (tail-biting) case.  We have some powerful general duality theorems, which have nice theoretical and practical applications.  Recently, some progress has been made in establishing conditions under which general graphical realizations may be ``locally reduced,” using extensions of linear-system-theoretic concepts such as observability and controllability. However, the theory of general graphical realizations remains wide open.
G. David Forney, Jr. received the B.S.E. degree in electrical engineering from Princeton University, Princeton, NJ, in 1961, and the M.S. and Sc.D. degrees in electrical engineering from the Massachusetts Institute of Technology, Cambridge, MA, in 1963 and 1965, respectively.
From 1965-99 he was with the Codex Corporation, which was acquired by Motorola, Inc. in 1977, and its successor, the Motorola Information Systems Group, Mansfield, MA.  Since 1996, he has been an Adjunct Professor at M.I.T.
Dr. Forney was Editor of the IEEE Transactions on Information Theory from 1970 to 1973.  He has been a member of the Board of Governors of the IEEE Information Theory Society during 1970-76, 1986-94, and 2004-10, and was President in 1992 and 2008.  He is currently a member of the IEEE Awards Board, and Chair of its Awards Review Committee.  He has been awarded the 1970 IEEE Information Theory Group Prize Paper Award, the 1972 IEEE Browder J. Thompson Memorial Prize Paper Award, the 1990 and 2009 IEEE Donald G. Fink Prize Paper Awards, the 1992 IEEE Edison Medal, the 1995 IEEE Information Theory Society Claude E. Shannon Award, the 1996 Christopher Columbus International Communications Award, the 1997 Marconi International Fellowship, an IT Golden Jubilee (1998) Award for Technological Innovation, two IT Golden Jubilee Paper Awards, and the 2011 IEEE Information Theory Society Aaron D. Wyner Distinguished Service Award.  He received an honorary doctorate from EPFL, Lausanne, Switzerland in 2007.  He was elected a Fellow of the IEEE in 1973, a member of the National Academy of Engineering (U.S.A.) in 1983, a Fellow of the American Association for the Advancement of Science in 1993, an honorary member of the Popov Society (Russia) in 1994, a Fellow of the American Academy of Arts and Sciences in 1998, and a member of the National Academy of Sciences (U.S.A.) in 2003.