Downlink Power Allocation Optimization in Pattern Division Multiple Access

Non-orthogonal multiple access (NOMA), in particular pattern division (PDMA), has been recently considered as the critical technologies deployed for 5G applications. However, optimizing power allocation (PA) at base station (BS) to increase sum throughput of downlink (DL) PDMA system still remains a challenge. Although this problem explored some extent by assuming that BS can obtain perfect channel state information (CSI), assumption is unfeasible harsh environments. Therefore, effectively improve communications real world, we propose using with optimized PA. With CSI, iterative (IPA) iteratively update Lagrange multipliers proposed. Using Karush-Kuhn-Tucher (KKT) conditions, PA solution closed-form expressions derived from increasing throughput. imperfect outage probability when maximizing The probabilistic mixture be converted into non-probability problem, and thus, under CSI proposed IPA algorithm. simulation results demonstrate scheme outperforms existing schemes effective