论文标题
依靠混合预编码
Weighted Sum Rate Maximization of the mmWave Cell-Free MIMO Downlink Relying on Hybrid Precoding
论文作者
论文摘要
依靠混合预编码的无细胞MIMO概念构成了一种创新技术，能够显着增加毫米波（MMWAVE）通信系统的网络容量。它分配了常规多细胞MIMO系统的细胞边界，同时通过限制接入点（APS）的射频（RF）链的数量大大降低功耗。在本文中，我们旨在通过构想低复杂性杂种预编码算法来最大化MMWave无细胞MIMO系统的加权总和速率（WSR）。我们制定了WSR优化问题，但要受到每个AP的发射功率约束，并且对模拟预码器的相位变速器的恒定模式约束。为迭代解决该问题提出了块坐标下降（BCD）算法。在每次迭代中，将经典的拉格朗日乘数方法和罚款双分解（PDD）方法合并，以获得近乎最佳的混合模拟/数字预编码矩阵。此外，我们扩展了我们提出的算法，用于为完全无细胞的MIMO系统的预编码提供封闭形式表达式。此外，我们介绍了我们提出的方法的融合分析和复杂性分析。最后，我们的仿真结果证明了针对完全数字和混合预编码矩阵提出的算法的优势。
The cell-free MIMO concept relying on hybrid precoding constitutes an innovative technique capable of dramatically increasing the network capacity of millimeter-wave (mmWave) communication systems. It dispenses with the cell boundary of conventional multi-cell MIMO systems, while drastically reducing the power consumption by limiting the number of radio frequency (RF) chains at the access points (APs). In this paper, we aim for maximizing the weighted sum rate (WSR) of mmWave cell-free MIMO systems by conceiving a low-complexity hybrid precoding algorithm. We formulate the WSR optimization problem subject to the transmit power constraint for each AP and the constant-modulus constraint for the phase shifters of the analog precoders. A block coordinate descent (BCD) algorithm is proposed for iteratively solving the problem. In each iteration, the classic Lagrangian multiplier method and the penalty dual decomposition (PDD) method are combined for obtaining near-optimal hybrid analog/digital precoding matrices. Furthermore, we extend our proposed algorithm for deriving closed-form expressions for the precoders of fully digital cell-free MIMO systems. Moreover, we present the convergency analysis and complexity analysis of our proposed method. Finally, our simulation results demonstrate the superiority of the algorithms proposed for both fully digital and hybrid precoding matrices.
