Energy Efficient User Clustering and Hybrid Precoding for Terahertz MIMO-NOMA Systems
Haisen Zhang, Haijun Zhang, Wei Liu, Keping Long, Jiangbo Dong, Victor C. M. Leung
Abstract
Terahertz (THz) band communication has been widely studied to meet the future demand for ultra-high capacity. In addition, multi-input multi-output (MIMO) technique and non-orthogonal multiple access (NOMA) technique with multiantenna also enable the network to serve more users. In this paper, we study the maximization of energy efficiency (EE) problem in THz-NOMA-MIMO systems for the first time. And the original optimization problem is divided into user clustering and hybrid precoding. Based on channel correlation characteristics, a fast convergence scheme for user clustering using enhanced K-means machine learning algorithm is proposed. Considering the power consumption and complexity, the hybrid precoding scheme based on the sub-connection structure is adopted. The simulation results show that the proposed scheme can achieve faster convergence and higher EE.