In this paper, we investigate an intelligent reflect surface (IRS) assisted multi-user millimeter wave (mmWave) downlink communication system, exploiting IRS to alleviate the blockage effect and enhance the performance of the mmWave system. Considering the impact of IRS on user association, we formulate a sum rate maximization problem by jointly optimizing the passive beamforming at IRS and user association, which is an intractable non-convex problem. Then an alternating optimization algorithm is proposed to solve the problem efficiently. In the proposed algorithm, passive beamforming at IRS is optimized by utilizing the fractional programming method and user association is solved through the network optimization based auction algorithm. We provide numerical comparisons between the proposed algorithm and different reference algorithms. Simulation results demonstrate that the proposed algorithm can achieve significant gains in the sum rate of all users.

中文翻译：

---

IRS 辅助毫米波系统的联合无源波束成形和用户关联优化

在本文中，我们研究了智能反射面 (IRS) 辅助多用户毫米波 (mmWave) 下行链路通信系统，利用 IRS 来减轻阻塞效应并提高毫米波系统的性能。考虑到 IRS 对用户关联的影响，我们通过联合优化 IRS 和用户关联处的无源波束成形来制定一个总速率最大化问题，这是一个棘手的非凸问题。然后提出一种交替优化算法来有效地解决该问题。在所提出的算法中，利用分数规划方法优化IRS的被动波束成形，并通过基于网络优化的拍卖算法解决用户关联问题。我们提供了所提出算法和不同参考算法之间的数值比较。