Layered Security Multicast Algorithm based on Security Energy Efficiency Maximization in SCMA Networks

This paper studies the hierarchical secure multicast algorithm in sparse code multiple access (SCMA) networks, its network security capacity is no longer limited by the users with the worst channel quality in multicast group. Firstly, we propose a network security energy efficiency (SEE) maximization problem. Secondly, in order to reduce the computational complexity, we propose a suboptimal algorithm (SA), which separates the codebook assignment with artificial noise from the power allocation with artificial noise. To further decrease the complexity of Lagrange method, a power allocation algorithm with increased fixed power is introduced. Finally, simulation results show that the network performance of the proposed algorithm in SCMA network is significantly better than that in orthogonal frequency division multiple access (OFDMA) network.