发表机构
KTH Royal Institute of Technology（皇家理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对丰富散射环境中不完美信道状态信息的问题，本文提出含导频传输、MMSE估计与ZF预编码的端到端框架，通过粒子群优化天线位置，揭示阵列几何与预编码器的耦合关系，为MA系统设计提供指导。
AI 中文摘要
6G及下一代通信对高频谱效率日益增长的需求，推动了对能利用多径传播信道空间结构的自适应天线架构的研究。传统基站阵列采用固定阵元位置部署，无法适配传播信道的瞬时空间结构。相比之下，可移动天线（MA）系统可动态重构天线位置，使阵列几何结构能跟踪当前用户集的信道特性。尽管现有MA研究在完美或统计信道状态信息（CSI）假设下已证明有显著增益，但不完美瞬时CSI、天线放置优化与预编码器设计之间的相互作用却鲜有关注。本文通过提出一种实用端到端框架来填补这一空白，该框架涵盖上行链路导频传输、基于聚类多径模型的MMSE信道估计，以及由估计CSI设计的下行链路ZF预编码。天线位置通过粒子群优化算法，以总速率最大化和最大-最小公平性两个目标进行优化。仿真结果表明，MA增益在稀疏、近视距（LoS）传播下最为显著，且随信道丰富度增加而减弱。此外，研究揭示了阵列几何结构与预编码器设计之间存在基本耦合：面向公平性的天线几何结构会编码空间公平性信息，该信息仅在采用兼容功率分配策略评估时才可恢复；不匹配的预编码器会完全掩盖几何优势，导致对天线放置对优化目标选择的鲁棒性得出误导性结论。这些发现为实际运行条件下可移动天线系统的设计与评估提供了具有实际意义的指导。
英文摘要
The growing demand for high spectral efficiency in 6G and beyond has driven research into adaptive antenna architectures capable of exploiting the spatial structure of multipath propagation channels. Conventional base station arrays are deployed with fixed element positions and cannot adapt to the instantaneous spatial structure of the propagation channel. In contrast, movable antenna (MA) systems enable dynamic reconfiguration of antenna positions, allowing the array geometry to track the channel characteristics of the current user set. While prior MA studies have demonstrated significant gains under perfect or statistical channel state information (CSI) assumptions, the interplay between imperfect instantaneous CSI, antenna placement optimization, and precoder design has received limited attention. This paper addresses this gap by proposing a practical end-to-end framework encompassing uplink pilot transmission, MMSE channel estimation under a clustered multipath model, and downlink ZF precoding designed from estimated CSI. Antenna positions are optimized via particle swarm optimization under two objectives: sum-rate maximization and max-min fairness. Simulation results show that MA gains are most pronounced under sparse, near-LoS propagation and diminish as channel richness increases. Furthermore, we reveal a fundamental coupling between array geometry and precoder design: a fairness-oriented antenna geometry encodes spatial fairness information that is only recoverable when evaluated with a compatible power allocation strategy. A mismatched precoder can completely mask the geometric advantage, leading to misleading conclusions about the robustness of antenna placement to the choice of optimization objective. These findings provide practically relevant guidance for the design and evaluation of movable antenna systems under realistic operating conditions.
