Lu An-An, Chen Yan, Gao Xiqi
National Mobile Communications Research Laboratory (NCRL), Southeast University, Nanjing 210096, China.
Purple Mountain Laboratories, Nanjing 211111, China.
Entropy (Basel). 2021 Jul 13;23(7):887. doi: 10.3390/e23070887.
In this paper, we propose a novel broad coverage precoder design for three-dimensional (3D) massive multi-input multi-output (MIMO) equipped with huge uniform planar arrays (UPAs). The desired two-dimensional (2D) angle power spectrum is assumed to be separable. We use the per-antenna constant power constraint and the semi-unitary constraint which are widely used in the literature. For normal broad coverage precoder design, the dimension of the optimization space is the product of the number of antennas at the base station (BS) and the number of transmit streams. With the proposed method, the design of the high-dimensional precoding matrices is reduced to that of a set of low-dimensional orthonormal vectors, and of a pair of low-dimensional vectors. The dimensions of the vectors in the set and the pair are the number of antennas per column and per row of the UPA, respectively. We then use optimization methods to generate the set of orthonormal vectors and the pair of vectors, respectively. Finally, simulation results show that the proposed broad coverage precoding matrices achieve nearly the same performance as the normal broad coverage precoder with much lower computational complexity.
在本文中，我们针对配备超大型均匀平面阵列（UPA）的三维（3D）大规模多输入多输出（MIMO）系统提出了一种新颖的宽覆盖预编码器设计。假设期望的二维（2D）角功率谱是可分离的。我们采用了文献中广泛使用的每天线恒定功率约束和半酉约束。对于常规的宽覆盖预编码器设计，优化空间的维度是基站（BS）天线数量与发射流数量的乘积。利用所提出的方法，高维预编码矩阵的设计被简化为一组低维正交向量以及一对低维向量的设计。该集合中的向量以及这对向量的维度分别是UPA每列和每行的天线数量。然后，我们分别使用优化方法来生成该组正交向量和这对向量。最后，仿真结果表明，所提出的宽覆盖预编码矩阵在计算复杂度低得多的情况下实现了与常规宽覆盖预编码器几乎相同的性能。
