Ribeiro, F., Ribeiro, F., Guerreiro, J., Guerreiro, J., R. Dinis, Cercas, F....D. Jayakody (2019). Multi-user detection for the downlink of NOMA systems with multi-antenna schemes and power-efficient amplifiers. Physical Communication, 33, 199?205. https://doi.org/10.1016/j.phycom.2019.01.003