A two-user downlink network aided by a reconfigurable intelligent surface is considered. The weighted sum signal to interference plus noise ratio maximization and the sum rate maximization models are presented, where the precoding vectors and the RIS matrix are jointly optimized. Since the optimization problem is non-convex and difficult, new approximation models are proposed. The upper bounds of the corresponding objective functions are derived and maximized. Two new algorithms based on the alternating direction method of multiplier are proposed. It is proved that the proposed algorithms converge to the KKT points of the approximation models as long as the iteration points converge. Simulation results show the good performances of the proposed models compared to state of the art algorithms.

翻译：使用可重新配置的智能表面辅助的双用户下行链路网络。 显示干扰的加权总和信号,加上噪声比最大化和总比率最大化模型,共同优化预编码矢量和RIS矩阵。 由于优化问题不复杂,因此提出了新的近似模型。 相应的客观功能的上限得到推算和最大化。 提出了基于乘数交替方向方法的两种新的算法。 证明拟议的算法在迭代点汇合近似模型的KKT点,只要迭代点汇合即可。 模拟结果显示拟议模型与艺术算法状态相比的良好表现。