Power Allocation in Downlink PDMA Systems

Pattern division multiple access (PDMA) is a multi- carrier non-orthogonal multiple access (NOMA), which can meet the requirements of massive user connections and super-high data rate in the fifth generation (5G) wireless networks. In this paper, we work on the optimization of power allocation to improve the performance of the downlink PDMA system significantly. Considering the perfect channel state information (CSI) is acquired at the transmitter, we propose an iterative power allocation (IPA) scheme based on the integration of the iterative subgradient method and the Mann iterative method. Moreover, Lagrange multipliers and the allocated power are updated until converged in each iteration. It is demonstrated in simulation results that the achievable sum throughput superiority of our proposed scheme over other schemes.