A Joint Iterative Optimal Resource Allocation Algorithm for Non-Orthogonal Multi-User and Multi-Weight Opportunistic Beamforming Systems
A Joint Iterative Optimal Resource Allocation Algorithm for Non-Orthogonal Multi-User and Multi-Weight Opportunistic Beamforming Systems
复制标题
非正交多用户多权值机会波束形成系统的联合迭代最优资源分配算法
DOI：
10.1109/tvt.2020.2965540
复制
发表时间：
2020-03-01
影响因子：
6.8
通讯作者：
Leung, Victor C. M.
中科院分区：
文献类型：
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作者：
Sun, Wen-Bin;Yu, Qi-Yue;Leung, Victor C. M.
机会波束形成（OBF）是无线通信领域一个有吸引力的研究课题，它能以较低的复杂度提供多用户分集。传统的OBF技术需要大量的等待用户，不能同时支持多个用户。为了解决上述问题，本文提出了一种下行多用户多权重机会波束形成非正交多址（MW-OBF-NOMA）系统。为了使系统的和谱效率（SE）最大化，建立了一个目标函数，但该目标函数是一个非凸问题，难以求出最优解。为了解决这个非凸问题，我们将其分为两个次优问题，逐一求解。基于这两个次优问题的解，提出了一种联合迭代资源分配算法。此外，我们讨论了信噪比（SNR）估计的影响，并推导了误码率（BER）的封闭表达式。数值计算结果表明，该系统可以在不增加资源的情况下同时为多个用户服务，并以较低的复杂度实现了改进的和SE。
Opportunistic beamforming (OBF) is an attractive research topic in wireless communications, which can provide multi-user diversity with a low complexity. The conventional OBF technique requires a large number of waiting users, and cannot simultaneously support multiple users. In order to solve the mentioned problem, this paper proposes a downlink multi-user multi-weight opportunistic beamforming non-orthogonal multiple access (MW-OBF-NOMA) system. An objective function is formulated to maximize the sum spectrum efficiency (SE) of the proposed system, however, it is a non-convex issue and intractable to derive an optimal solution. To solve this non-convex issue, we divide it into two sub-optimal issues and solve them one-by-one. Based on the solutions of the two sub-optimal issues, a joint iterative resource allocation algorithm is presented. Moreover, we discuss the influences of signal-to-noise ratio (SNR) estimation, and deduce a closed-form expression of bit error ratio (BER). Numerical results show that our proposed system can simultaneously serve multiple users without extra resources, and achieve an improved sum SE with a low complexity.