Coding and Modulation for Communication at the Shannon Limit

Dr.-Ing. Georg Böcherer

Institute for Communications Engineering, Technical University of Munich

Abstract:

The additive white Gaussian noise (AWGN) channel is a reasonable model for many practical scenarios in wired, wireless, and optical communications. Communication schemes used in current standards have an inherent performance gap of up to 1.53 dB to the Shannon capacity, because of suboptimal uniformly distributed signaling. In the first part of this talk, a recently developed higher-order modulation scheme is presented, which operates very close to the Shannon capacity and has an unprecedented flexibility to adapt the transmission rate to the channel quality. The scheme is based on probabilistic amplitude shaping (PAS), which separates signal shaping and forward error correction (FEC). Signal shaping is implemented by constant composition distribution matching (CCDM). Results from an optical experiment are presented, which illustrate the feasibility of the scheme for practical applications. In the second part of the talk, PAS with CCDM is analyzed from an information theoretic point of view. By random coding arguments, it is shown that PAS with CCDM provably achieves the Shannon capacity, asymptotically in the block length. The talk is concluded with an outline of open problems for future research.

Biography:

Georg Böcherer obtained his MSc degree in Electrical Engineering and Information Technology from the ETH Zürich. He spent one semester at the EPF Lausanne and wrote his master thesis at the Federal University of Pernambuco in Recife, Brazil. From 2007 to 2012 he worked towards his PhD degree at the Institute of Theoretical Information Technology at RWTH Aachen University. Since April 2012, he is with the Institute for Communications Engineering at Technische Universität München. His PhD thesis on probabilistic shaping received the E-Plus Dissertation Award. His work on coding for the ICT Cubes received the best paper award at ISWCS 2011. Together with two of his former master students, he won a Bell Labs Prize in 2015. He was a co-organizer of the Munich Workshop on Coding and Modulation (MCM 2015).