In millimeter wave (mmWave) massive MIMO (multiple-input multiple-output) systems, it is difficult to apply conventional digital precoding techniques due to hardware constraints. Fortunately, the hybrid precoding can be utilized to reduce power consumption and high costs. In this paper, a codebook-based hybrid precoding scheme for downlink multiuser mmWave massive MIMO systems is proposed. Our main idea is that the analog and digital precoders are designed separately to maximize the achievable sum rate. In the analog domain, we take the potential multiuser conflict and angular domain of channel matrix into consideration and propose an efficient conflicting-aware (CA) beam-column selection method to obtain a discrete Fourier transform (DFT) codebook-based analog precoder. According to the CA method, all users are classified into two groups, i.e., conflicting users (CUs) and non-conflicting users (NCUs). Different criteria of beam-column selection are applied for the two user groups. Then, zero-forcing (ZF) digital precoder is directly used in the digital domain. Simulation results illustrate that our proposed algorithm which has low complexity achieves satisfactory SR performance, which approaches that of the full digital precoding (the upper bound) and outperforms other existing hybrid algorithms.

在毫米波（mmWave）大规模MIMO（多输入多输出）系统中，由于硬件限制，很难应用常规的数字预编码技术。幸运的是，可以利用混合预编码来减少功耗和高成本。本文提出了一种针对下行多用户毫米波大规模MIMO系统的基于码本的混合预编码方案。我们的主要思想是模拟和数字预编码器是分开设计的，以最大程度地实现可实现的总速率。在模拟域中，我们考虑了潜在的多用户冲突和信道矩阵的角域，并提出了一种有效的冲突感知（CA）波束列选择方法，以获得基于离散傅里叶变换（DFT）码本的模拟预编码器。根据CA方法，所有用户都分为两组，即 冲突的用户（CU）和非冲突的用户（NCU）。对两个用户组应用不同的梁柱选择标准。然后，迫零（ZF）数字预编码器直接用于数字领域。仿真结果表明，我们提出的算法具有较低的复杂度，可以达到令人满意的SR性能，接近全数字预编码（上限）的性能，并且优于其他现有的混合算法。