Spatial pulse position modulation for multi-mode transmission systems. - John van Weerdenburg; Alex Alvarado; Juan Carlos Alvarado-Zacarias; Jose Enrique Antonio-Lopez; J. H. Bonarius; D. Molin; Marianne Bigot-Astruc; Antonius M. J. Koonen; Adrian Amezcua Correa; Pierre Sillard; Rodrigo Amezcua Correa; Chigo M. Okonkwo (OFC, 2017)