Frans M. J. Willems

Panelist during the Award Recipient Panel and 2025 IEEE Richard W. Hamming Medal Recipient

Frans M. J. Willems has made pioneering contributions to core areas of information theory. He has had a profound and lasting impact not only on theory but also as a thought leader in realizing applications. In 1982, Willems stunned the information theory community with his first paper on the multiple-access channel (MAC), in which he established the capacity region of a class of MAC channels with feedback. Beforehand, this capacity region was unknown for non-trivial MACs. His dissertation, for which he received the prestigious Marconi Young Scientist award, was a milestone in multi-user information theory. It included many other significant results on MACs with cribbing encoders, partial feedback, partially cooperating encoders, and generalized feedback. His analysis of the repetition-time algorithm revealed for the first time the connection between Lempel-Ziv-like methods and Kac’s theorem. This work received international acclaim and stimulated other researchers to further investigate Lempel-Ziv methods, which resulted in proof of the fact that Lempel-Ziv 77 achieves entropy for ergodic sources. Later in his career, Willems proposed a second universal data compression algorithm. The context-tree weighting method, developed jointly with Y.M. Shtarkov and T.J. Tjalkens, is a coding technique that combines computational efficiency with optimal redundancy behavior for tree sources. The compression rate that context-tree weighting achieves is excellent for many data types, including natural language. Many researchers now use this textbook-algorithm as a baseline for their investigations. Overall, Willems’ work has culminated in key contributions to patent portfolios, products, and strategies at companies such as Royal KPN, Philips, Catena Radio Systems, NXP Semiconductors, GenKey and Intrinsic-ID.

An IEEE Life Fellow, Willems is Full Professor Emeritus, Eindhoven University of Technology, Eindhoven, Netherlands.