Rate Splitting, Superposition Coding and Binning for Groupcasting over the Broadcast Channel: A General Framework

A general inner bound is given for the discrete memoryless broadcast channel with an arbitrary number of users and general message sets, a setting that accounts for the most general form of concurrent groupcasting, with messages intended for any set of subsets of receivers. Achievability is based on superposition coding and rate-splitting without and with binning, where each receiver jointly decodes both its desired messages as well as the partial interference assigned to it via rate-splitting. The proof of achievability builds on the techniques for the description and analysis of superposition coding recently developed by the authors for the multiple-access channel with general messages as well as a new recursive mutual covering lemma for the analysis of the more general achievable scheme with binning.
Comment: 8 pages. This work was presented in part at the 2017 IEEE International Symposium on Information Theory, Aachen, Germany, 2017, and appears in part in that symposium's proceedings. It was performed when the first author was a doctoral student at the University of Colorado, Boulder, and appears in his Ph.D. thesis