SCMA网络中基于保密能量效率最大化的分层安全多播策略

Layered Security Multicast Scheme Based on Security Energy Efficiency Maximization in SCMA Networks

首先,研究稀疏码多址接入(sparse code multiple access,SCMA)网络中的分层安全多播策略,来克服多播组的保密容量受限于组内最差用户信道条件的问题。其次,解决了网络保密能量效率最大化的最优化问题。为了减少解决最优化问题的计算复杂度,又提出了添加人工噪声下码本分配与功率分配的次优化算法(sub-optimization algorithm,SA)。仿真结果表明,本文提出的SA算法在基于SCMA网络中的网络保密能量效率方面要优于采用传统安全多播(conventional security multicast,CSM)策略的SCMA网络和基于正交频分多址(orthogonal frequency division multiple access,OFDMA)网络,并且提出的SA算法在SCMA网络中的安全多播系统功效要优于在OFDMA网络中的安全多播系统功效。

In this paper, we first study the layered security multicast scheme in SCMA(sparse code multiple access)network,whose system security capacity is no longer limited by the worst channel quality user in the multicast group. Secondly, we formulate a network security energy efficiency(SEE) maximization problem. In order to reduce the computational complexity, we then propose a suboptimization algorithm(SA) by separating codebook assignment and power allocation with artificial noise. Finally, the simulation results verify that the network SEE of the proposed algorithm significantly outperforms the conventional security multicast(CSM) scheme in SCMA systems and orthogonal frequency division multiple access(OFDMA) systems. Moreover, the security multicast performance of SCMA systems with SA is better than that of OFDMA systems with SA.