Séminaire ICI : Nicolas Charpenay

Titre du séminaire et orateur

Variable-length coding for zero-error information transmission.

Nicolas Charpenay (ENS Paris-Saclay)

Date et lieu

Jeudi 10 octobre 2019, 11h.

Salle 384, ENSEA


The zero-error information theory aims at designing coding schemes in which the probability of a correct decoding is exactly equal to one. The zero-error capacity of a channel was defined in Shannon (1956) as the maximum asymptotic rate that can be reached with zero-error codes. In general, the characterization of the zero-error capacity is a wide open problem, even if some particular cases are solved. In this work, I will propose a new approach based on variable-length codes. The first result provides a single-letter expression for the asymptotic performances of this family of variable-length codes. The second result proves the optimality of intermingled variable-length codes for an example where no finite-length code could reach the zero-error capacity. These results are also connected to the problem of channel coding in the finite block-length regime.


Nicolas Charpenay is currently a student in Mathematics at the ENS Paris-Saclay doing an internsip at the ETIS laboratory. He graduated in M2 Optimization at Paris-Sud university, and will join Fribourg university (Switzerland) for a pre-doctoral year of reseach in Combinatorics.