Advanced Channel Decomposition Techniques in OTFS: A GSVD Approach for Multi-User Downlink. - Omid Abbassi Aghd; Oussama Ben Haj Belkacem; Dou Hu; João Guerreiro 001; Nuno Souto; Michal Szczachor; Rui Dinis 001 (CoRR, 2025)