*Article* **Energy Harvesting Maximizing for Millimeter-Wave Massive MIMO-NOMA**

#### **Shufeng Li \*, Zelin Wan, Libiao Jin and Jianhe Du**

School of Information and Communication Engineering, Communication University of China, Beijing 100024, China; 13787218609@163.com (Z.W.); libiao@cuc.edu.cn (L.J.); dujianhe1@163.com (J.D.)

**\*** Correspondence: lishufeng@cuc.edu.cn; Tel.: +86-1355-2288-205

Received: 23 November 2019; Accepted: 24 December 2019; Published: 26 December 2019

**Abstract:** Multiple-Input Multiple-Output Non-Orthogonal Multiple Access (MIMO-NOMA) is considered a promising multiple access technology in fifth generation (5G) networks, which can improve system capacity and spectral efficiency. In this paper, we proposed two methods of user grouping and proposed a dynamic power allocation solution for MIMO-NOMA system. Then we proposed an algorithm to maximize energy harvest for MIMO-NOMA system by integrating Simultaneous Wireless Information and Power Transfer (SWIPT), known as maximizing energy harvesting. Specifically, we added a power splitter at the receiver and found the optimal power splitting factor for each user. The harvested power of the user is maximized under the premise of satisfying the minimum communication rate. The simulation results show that the proposed method is effective.

**Keywords:** MIMO; NOMA; precoding; power allocation; user-clustering; power splitter
