Non-orthogonal multiple access systems with wireless energy harvesting

Non-orthogonal multiple access (NOMA) is a candidate multiple access scheme in 5G systems for the simultaneous access of tremendous number of wireless nodes. On the other hand, RF-enabled wireless energy harvesting is a promising technology for self-sustainable wireless nodes. In this paper, we consider a NOMA system where the near user harvests energy from the strong radio signal to power-on the information decoder. A generalized energy harvesting framework is proposed by combining the conventional time switching and power splitting scheme, and the achievable rate regions for time switching and power splitting are characterized in closed-form. Numerical results demonstrate the relationship among generalized scheme, time switching scheme and power splitting scheme.