A Spectral Efficient Spatially Modulated Non-orthogonal Multiple Access for 5G

Non-orthogonal multiple access (NOMA) is a promising candidate for 5G networks. NOMA achieves superior spectral efficiency than conventional orthogonal multiple access (OMA), as in NOMA multiple users can use the same time and frequency resources. Multiple-Input-multiple-output is a promising technique that can enhance system performance. In this paper we present a multiple antenna based NOMA, known as spatially modulated NOMA. In proposed scheme different users are multiplexed in power domain while cell edge users are multiplexed in spatial domain. The information to cell edge users are conveyed using antenna indices thereby reduces number of decoding steps at NOMA users, cell edge interference reduces as no power is allocated to cell edge users and hence is more energy efficient as compare to conventional NOMA. Simulation results shows that proposed scheme achieves superior spectral efficiency as compare to conventional NOMA.