In this paper, we investigate the outage performance of an intelligent reflecting surface (IRS)-assisted non-orthogonal multiple access (NOMA) uplink, in which a group of the surface reflecting elements are configured to boost the signal of one of the user equipments (UEs), while the remaining elements are used to boost the other one. By approximating the received powers of the UEs as Gamma random variables, tractable expressions for the outage probability under NOMA interference cancellation (IC) are obtained. We then evaluate the outage over different splits of the elements and pathloss differences between the two UEs. The analysis shows that for small pathloss differences, the split should be chosen such that most of the IRS elements are configured to boost the stronger UE, while for large pathloss differences, it is more beneficial to boost the weaker UE. Finally, we investigate a robust selection of the elements' split under the criterion of minimizing the maximum outage between the two UEs.

翻译：在本文中, 我们调查了一个智能反射表面( IRS) 辅助非垂直多存取( NOMA) 的上链路的失灵性能, 在上链路中, 一组表面反射元素被配置以提升一个用户设备( UES) 的信号, 而其余元素则用来提升另一个用户设备( UES ) 的信号。 通过将获得的 UES 接收到的能量作为 Gamma 随机变量, 可以获得NOMA 干扰取消( IC) 下断电概率的可移动表达式 。 然后我们评估两个 UES 之间元素的不同分割和路径损差差异的溢出。 分析显示, 对于小路径损差异, 应该选择部分表面反射元素, 使大多数IRS 元素被配置为增强更大的 UE, 而对于大的路径损耗损差异, 则更有利于提振弱的 UE。 最后, 我们根据最小化两个 UES之间最大外差的标准, 对元素的断裂进行严格选择 。