Hybrid precoding is widely used in millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) systems. However, most prior work on hybrid precoding focused on the fully connected hybrid architectures and the subconnected but fixed architectures in which each radio frequency (RF) chain is connected to a specific subset of the antennas. The limited work shows that dynamic subarray architectures address the tradeoff between achievable spectral efficiency and energy efficiency of mmWave massive MIMO systems. Nevertheless, in the multiuser hybrid precoding systems, the existing dynamic subarray schemes ignore the fairness of users and the problem of user selection. In this paper, we propose a novel multiuser hybrid precoding scheme for dynamic subarray architectures. Firstly, we select a multiuser set among all users according to the analog effective channel information of the base station (BS) and then design the subset of the antennas to each RF by the fairness antenna-partitioning algorithm. Finally, the optimal analog precoding vector is designed according to each subarray, and the digital precoding is designed by the minimum mean-squared error (MMSE) criterion. The simulation results show that the performance advantages of the proposed multiuser hybrid precoding scheme for dynamic subarray architectures.

中文翻译：

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多用户毫米波大规模MIMO系统的动态子阵列连接混合预编码方案

混合预编码广泛用于毫米波（mmWave）大规模多输入多输出（MIMO）系统中。但是，关于混合预编码的大多数现有工作都集中在完全连接的混合体系结构和子连接但固定的体系结构中，其中每个射频（RF）链都连接到天线的特定子集。有限的工作表明，动态子阵列架构可解决mmWave大规模MIMO系统可实现的频谱效率与能效之间的折衷问题。然而，在多用户混合预编码系统中，现有的动态子阵列方案忽略了用户的公平性和用户选择的问题。在本文中，我们为动态子阵列架构提出了一种新颖的多用户混合预编码方案。首先，我们根据基站（BS）的模拟有效信道信息在所有用户中选择一个多用户集，然后通过公平天线划分算法为每个RF设计天线子集。最后，根据每个子阵列设计最佳的模拟预编码矢量，并根据最小均方误差（MMSE）准则设计数字预编码。仿真结果表明，所提出的多用户混合预编码方案在动态子阵列架构上具有性能优势。数字预编码是根据最小均方误差（MMSE）准则设计的。仿真结果表明，所提出的多用户混合预编码方案在动态子阵列架构上具有性能优势。数字预编码是根据最小均方误差（MMSE）准则设计的。仿真结果表明，所提出的多用户混合预编码方案在动态子阵列架构上具有性能优势。