Besides traditional orthogonal multiple access (OMA), 5G and other future wireless communication systems will also involve non-orthogonal multiple access (NOMA). In that context, the combination of NOMA systems with the popular orthogonal frequency-division multiplexing (OFDM) will arise naturally in highly spectral efficient communications. Since OFDM signals are very prone to nonlinear distortion effects, the receiver design of NOMA-OFDM systems should be modified accordingly. In this work, we consider an efficient, nonlinear power amplification for NOMA-OFDM systems and we propose different reception strategies to cope with the nonlinear distortion. It is shown that the performance of conventional power-domain NOMA is very poor under nonlinear transmission scenarios. However, it is also demonstrated that Bussgang receivers combined with optimum detection schemes might be an excellent alternative ¹ .