Exact BER Performance Analysis for Downlink NOMA Systems Over Nakagami-m Fading Channels Assaf, Tasneem ; Al-Dweik, Arafat ; Moursi, Mohamed El ; Zeineldin, Hatem Abstract Publication: IEEE Access Pub Date: 2019 DOI: 10.1109/ACCESS.2019.2942113 Bibcode: 2019IEEEA...7m4539A