Millimeter-Wave NOMA With User Grouping, Power Allocation and Hybrid Beamforming
Millimeter-Wave NOMA With User Grouping, Power Allocation and Hybrid Beamforming
复制标题
具有用户分组、功率分配和混合波束成形的毫米波 NOMA
DOI：
10.1109/twc.2019.2932070
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发表时间：
2019-11-01
影响因子：
10.4
通讯作者：
Xia, Xiang-Gen
中科院分区：
文献类型：
--
作者：
Zhu, Lipeng;Zhang, Jun;Xia, Xiang-Gen
研究了非正交多址接入技术在毫米波通信中的应用。特别地，我们考虑具有混合波束成形结构的下行链路传输。首先根据用户间的信道相关性提出了一种用户分组算法。然后，联合的混合波束成形和功率分配问题，制定最大化可实现的和速率，每个用户的最小速率约束。为了解决这一高维变量的非凸问题，首先得到了任意固定混合波束形成下的功率分配问题的解，将其分为组内功率分配和组间功率分配。然后，在给定任意固定模拟波束形成的情况下，利用近似迫零法设计数字波束形成，以最小化群间干扰。最后，用一种边界压缩粒子群优化算法求解了恒模约束下的模拟波束形成问题。仿真结果表明，所提出的联合方法，包括用户分组、混合波束形成和功率分配，在可实现的和速率和能量效率方面优于现有的方案和传统的毫米波正交多址系统。
This paper investigates the application of non-orthogonal multiple access in millimeter-Wave communications (mmWave-NOMA). Particularly, we consider downlink transmission with a hybrid beamforming structure. A user grouping algorithm is first proposed according to the channel correlations of the users. Whereafter, a joint hybrid beamforming and power allocation problem is formulated to maximize the achievable sum rate, subject to a minimum rate constraint for each user. To solve this non-convex problem with high-dimensional variables, we first obtain the solution of power allocation under arbitrary fixed hybrid beamforming, which is divided into intra-group power allocation and inter-group power allocation. Then, given arbitrary fixed analog beamforming, we utilize the approximate zero-forcing method to design the digital beamforming to minimize the inter-group interference. Finally, the analog beamforming problem with the constant-modulus constraint is solved with a proposed boundary-compressed particle swarm optimization algorithm. The simulation results show that the proposed joint approach, including user grouping, hybrid beamforming and power allocation, outperforms the state-of-the-art schemes and the conventional mmWave orthogonal multiple access system in terms of achievable sum rate, and energy efficiency.