In this work, in order to achieve higher spectrum efficiency, we propose a reconfigurable intelligent surface (RIS)-assisted multi-user communication uplink system. Different from previous work in which the RIS only optimizes the phase of the incident users’ signal, we propose the use of the RIS to create a virtual constellation diagram to transmit the data of an additional user. We focus on the two-user case and develop a tight approximation for the probability distribution function (PDF) of the minimum distance between constellation points of both users. Then, based on the proposed statistical distribution, we derive the analytical expressions of the average bit error rate of the considered two users. The letter also shows the trade off between the performance of two users as a function of the proposed phase shift at the RIS.

中文翻译：

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一种新颖的 RIS 辅助调制方案

在这项工作中，为了实现更高的频谱效率，我们提出了一种可重构智能表面（RIS）辅助多用户通信上行链路系统。与之前的工作中 RIS 仅优化事件用户信号的相位不同，我们建议使用 RIS 创建虚拟星座图来传输额外用户的数据。我们专注于两个用户的情况，并为两个用户的星座点之间的最小距离的概率分布函数 (PDF) 开发了一个严格的近似值。然后，基于所提出的统计分布，我们推导出所考虑的两个用户的平均误码率的解析表达式。这封信还显示了两个用户的性能之间的权衡，作为 RIS 上建议的相移的函数。