Beam selection is a notable issue for recent wireless communications. A conventional single beam selection (SBS) concept is utilized to minimize the number of necessary radio frequency chains in millimeter-wave (mmWave) multiple-input multiple-output non-orthogonal multiple access (MIMO-NOMA) systems. In general, the traditional SBS concept cannot implement a multiple beam group selection opportunity for every supported user. In this circumstance, the user side spends too much computational burden to measure the decoded message and suffer a beam optimization problem. Therefore, we propose a hybrid beam selection (HBS) scheme to utilize a multiple SBS scheme in beamspace MIMO-NOMA systems. Consequently, each supported user can easily achieve a low beam optimization problem by selecting a reliable SBS group from the proposed HBS scheme and significantly increase the spectral performance. Furthermore, we demonstrate an iterative beam power maximization algorithm utilizing the HBS scheme to solve the power allocation problem in this paper. The numerical results are verified by computer simulations in terms of a downlink beamspace MIMO-NOMA channel with a lens antenna array environment.

对于最近的无线通信，波束选择是一个值得注意的问题。利用常规的单波束选择（SBS）概念来最小化毫米波（mmWave）多输入多输出非正交多址（MIMO-NOMA）系统中必要的射频链数量。通常，传统的SBS概念无法为每个受支持的用户实现多波束组选择机会。在这种情况下，用户侧花费过多的计算负担来测量解码的消息并遭受波束优化问题。因此，我们提出了一种在波束空间MIMO-NOMA系统中利用多重SBS方案的混合波束选择（HBS）方案。所以，通过从提出的HBS方案中选择可靠的SBS组，每个受支持的用户都可以轻松实现近波束优化问题，并显着提高频谱性能。此外，本文演示了一种使用HBS方案的迭代波束功率最大化算法来解决功率分配问题。通过计算机仿真，在具有透镜天线阵列环境的下行链路波束空间MIMO-NOMA信道方面验证了数值结果。