Stierstorfer, Clemens; Fischer, Robert F. H. (Lehrstuhl für Informationsübertragung, Friedrich–Alexander–Universität Erlangen–Nürnberg, Cauerstraße 7/LIT, 91058 Erlangen, Germany)
In this paper mappings for square QAM constellations employed for bit-interleaved coded modulation (BICM) in ultra-wide band scenarios are assessed. It is shown that for low signal-to-noise ratios Gray mappings do not maximize the capacity of BICM schemes. Instead, mappings based on the component-wise application of the set-partitioning principle lead to maximum capacity. Construction guidelines for such mappings are given.