Power Allocation for SCMA Downlink Systems Based on Maximum Energy Efficiency

Sparse code multiple access(SCMA) is a novel kind of non-orthogonal multiple access technology which has the advantages of supporting more connections, low time delay and overcomes the near-far effect in CDMA system. In this paper we propose power allocation algorithms for SCMA downlink systems to maximize the energy efficiency. Since the resource allocation problem is non-convex, we employ the Lagrange dual decomposition method and Dinkelbach theory to solve the optimization problem. Our results shows that energy efficiency can be improved significantly by adopting optimal power allocation method. The SCMA maximum energy efficiency system save more energy in the condition of satisfying the user QoS requirement.