This paper studies the deployment of multiple movable antennas (MAs) at the base station (BS) for enhancing the multiuser communication performance. First, we model the multiuser channel in the uplink to characterize the wireless channel variation caused by MAs' movement at the BS. Then, an optimization problem is formulated to maximize the minimum achievable rate among multiple users for MA-aided uplink multiuser communications by jointly optimizing the MAs' positions, their receive combining at the BS, and the transmit power of users, under the constraints of finite moving region of MAs, minimum inter-MA distance, and maximum transmit power of each user. To solve this challenging non-convex optimization problem, a two-loop iterative algorithm is proposed by leveraging the particle swarm optimization (PSO) method. Specifically, the outer-loop updates the positions of a set of particles, where each particle's position represents one realization of the antenna positioning vector (APV) of all MAs. The inner-loop implements the fitness evaluation for each particle in terms of the max-min achievable rate of multiple users with its corresponding APV, where the receive combining matrix of the BS and the transmit power of each user are optimized by applying the block coordinate descent (BCD) technique. Simulation results show that the antenna position optimization for MAs-aided BS can significantly improve the rate performance as compared to conventional BS with fixed-position antennas (FPAs).

翻译：本文研究在基站（BS）部署多个可移动天线（MA）以提升多用户通信性能。首先，建立上行多用户信道模型，表征BS处MA移动引起的无线信道变化。随后，在MA移动区域有限、MA间最小距离以及各用户最大传输功率等约束条件下，通过联合优化MA位置、BS处接收合并矩阵及用户发射功率，构建了最大化MA辅助上行多用户通信中多用户最小可达速率的最优化问题。为解决这一具有挑战性的非凸优化问题，提出了一种基于粒子群优化（PSO）方法的双环迭代算法。具体而言，外环更新一组粒子的位置，其中每个粒子的位置代表所有MA的天线位置向量（APV）的一种实现；内环基于各粒子对应的APV，通过应用块坐标下降（BCD）技术优化BS接收合并矩阵与各用户发射功率，实现多用户最小可达速率适值评估。仿真结果表明，与传统固定位置天线（FPA）基站相比，MA辅助基站的天线位置优化可显著提升速率性能。