Outage Probability Constrained MIMO-NOMA Designs Under Imperfect CSI
Outage Probability Constrained MIMO-NOMA Designs Under Imperfect CSI
复制标题
不完美CSI下中断概率受限的MIMO-NOMA设计
DOI：
10.1109/twc.2018.2875490
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发表时间：
2018-12-01
影响因子：
10.4
通讯作者：
Fan, Pingzhi
中科院分区：
文献类型：
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作者：
Cui, Jingjing;Ding, Zhiguo;Fan, Pingzhi
非正交多址接入（NOMA）已被公认为是一种很有前途的多址接入方案，将用于第五代无线网络。在本文中，多输入多输出（MIMO）技术被应用到NOMA系统中，通过考虑两种类型的不完美的信道状态信息-信道分布信息（CDI）和信道估计的不确定性。基于这两种信道模型，在概率约束条件下，联合设计功率分配和波束形成向量，以最大化MIMO-NOMA的系统效用。由于NOMA中连续干扰消除的实现，每个簇中用户的功率分配系数变得耦合，这使得速率中断概率约束变得复杂，并导致两个具有挑战性的非凸问题。针对CDI下的优化问题，提出了一种基于一阶近似和半定规划（SDP）的连续凸近似（SCA）算法。针对信道估计不确定条件下的优化问题，提出了一种基于SCA和有效一维搜索的联合功率分配和接收波束形成算法，以最大化系统效用。此外，还讨论了这两个问题的收敛性和可行性.此外，一个有效的方法来寻找一个可行的初始解。仿真结果表明，在固定功率分配和波束形成的情况下，本文提出的两种算法的性能优于MIMO正交多址和MIMO固定NOMA（MIMO F-NOMA）。
Non-orthogonal multiple access (NOMA) has been recognized as a promising multiple access scheme to be used in fifth-generation wireless networks. In this paper, multiple-input and multiple-output (MIMO) techniques are applied to NOMA systems by considering two types of imperfect channel state information—channel distribution information (CDI) and channel estimation uncertainty. Based on the two considered channel models, the power allocation and beamforming vectors are jointly designed to maximize the system utility of MIMO-NOMA, subjected to probabilistic constraints. Due to the implementation of successive interference cancellation in NOMA, the power allocation coefficients of the users in each cluster become coupled, which complicates the rate outage probability constraints and results in two challenging non-convex problems. For the optimization problem under CDI, we propose an efficient successive convex approximation (SCA) algorithm based on first-order approximation and semidefinite programming (SDP). For the optimization problem under channel estimation uncertainty, a new algorithm for the joint power allocation and receive beamforming design is developed to maximize the system utility based on SCA and an efficient 1-D search. In addition, the convergence and the feasibility are discussed for the two formulated problems. Furthermore, an efficient method to find a feasible initial solution is provided. Finally, the presented simulation results validate that the proposed two algorithms outperform MIMO-orthogonal multiple access and MIMO fixed NOMA (MIMO F-NOMA) with fixed power allocation and beamforming.