标题： 6D可移动天线通过离散位置和旋转优化增强无线网络 显示英文标题

标题： 6D Movable Antenna Enhanced Wireless Network Via Discrete Position and Rotation Optimization

摘要： 六维可移动天线（6DMA）是一种通过根据用户的空闲分布和统计信道信息调整分布式天线表面的三维位置和三维旋转来提高无线网络容量的有效方法。 尽管连续定位/旋转6DMA表面可以实现最大的灵活性，从而获得最高的容量提升，但由于实际步进电机的离散运动限制，这很难实现。 因此，在本文中，我们考虑了一个仅具有有限数量可能的离散位置和旋转的6DMA辅助基站（BS）。 我们旨在通过联合优化基站上多个6DMA表面的三维位置和三维旋转，以最大化随机用户数量在随机位置下的平均网络容量，同时满足离散运动约束。 特别是，我们考虑了存在和不存在用户统计信道知识的实际情况，并分别利用蒙特卡罗和条件样本均值（CSM）方法提出了相应的离线和在线优化算法。 仿真结果验证了我们提出的离线和在线算法在6DMA表面的离散位置/旋转优化方面的有效性，与各种基准方案相比，这些基准方案包括固定位置天线（FPAs）和有限移动性的6DMAs。 结果表明，即使在离散位置/旋转约束下，通过利用用户的空闲分布特性，6DMA-BS可以显著提高无线网络容量。 显示英文摘要

摘要： Six-dimensional movable antenna (6DMA) is an effective approach to improve wireless network capacity by adjusting the 3D positions and 3D rotations of distributed antenna surfaces based on the users' spatial distribution and statistical channel information. Although continuously positioning/rotating 6DMA surfaces can achieve the greatest flexibility and thus the highest capacity improvement, it is difficult to implement due to the discrete movement constraints of practical stepper motors. Thus, in this paper, we consider a 6DMA-aided base station (BS) with only a finite number of possible discrete positions and rotations for the 6DMA surfaces. We aim to maximize the average network capacity for random numbers of users at random locations by jointly optimizing the 3D positions and 3D rotations of multiple 6DMA surfaces at the BS subject to discrete movement constraints. In particular, we consider the practical cases with and without statistical channel knowledge of the users, and propose corresponding offline and online optimization algorithms, by leveraging the Monte Carlo and conditional sample mean (CSM) methods, respectively. Simulation results verify the effectiveness of our proposed offline and online algorithms for discrete position/rotation optimization of 6DMA surfaces as compared to various benchmark schemes with fixed-position antennas (FPAs) and 6DMAs with limited movability. It is shown that 6DMA-BS can significantly enhance wireless network capacity, even under discrete position/rotation constraints, by exploiting the spatial distribution characteristics of the users.