AI 中文总结
该研究针对可移动天线系统，提出VIM-MA方法，将多普勒频移作为信息自由度，设计了闭式解的码本，推导了无需信道状态信息的检测器，仿真显示其性能优于位置域索引。
AI 中文摘要
在可移动天线（MA）系统中，天线移动会产生多普勒频移，传统上被视为需要抑制的损伤。本文提出可移动天线的速度索引调制（VIM-MA），将这种多普勒效应重新定义为额外的信息承载自由度。发射机从预设计的离散码本中选择天线移动速度，使产生的多普勒频移携带传统调制符号承载之外的额外索引比特。码本设计被建模为在速度间距δ和码本大小Nv上最大化频谱效率，约束条件包括速度估计精度的平均信息克拉美罗型界（AIF-CRB）、物理轨道长度约束以及空间信道去相关约束。通过对数变量变换将问题转化为凸问题，得到闭式解。进一步证明，峰值码本速度等于Dmax/Ts，且去相关限制的间距始终低于瑞利多普勒分辨率，因此VIM-MA本质上是一种超分辨率方案。推导得到的协方差匹配检测器既不需要每条路径的角度知识，也不需要信道状态信息。仿真结果表明，在10λ孔径上承载5个索引比特的去相关限制码本仅在拥有先验角度知识时可实现，而无信道状态信息的检测器虽仅能承载3个比特，但在实际导频预算下，其达到该有效载荷的时间比位置域索引早约10 dB。
英文摘要
In movable antenna (MA) systems, antenna movement induces Doppler frequency shifts that are conventionally treated as an impairment requiring mitigation. In this paper, we propose \emph{Velocity Index Modulation for Movable Antennas} (VIM-MA), which reframes this Doppler effect as an additional information-bearing degree of freedom. The transmitter selects the antenna movement velocity from a pre-designed discrete codebook, so that the resulting Doppler shift conveys extra index bits beyond those carried by the conventional modulation symbol. Codebook design is formulated as a spectral efficiency maximization over the velocity spacing $δ$ and codebook size $N_v$, subject to an average-information Cramér--Rao-type bound (AIF-CRB) on velocity estimation accuracy, a physical track length constraint, and a spatial channel decorrelation constraint. A logarithmic change of variables renders the problem convex and yields a closed-form solution. We further establish that the peak codebook velocity equals $D_{\max}/T_s$, and that the decorrelation-limited spacing always lies below the Rayleigh Doppler resolution, so that VIM-MA is intrinsically a super-resolution scheme. A covariance-matched detector is derived that requires neither per-path angle knowledge nor channel state information. Simulation results show that the decorrelation-limited codebook, which carries five index bits over a $10λ$ aperture, is attainable only with oracle angle knowledge, whereas the channel-state-free detector is limited to three bits but reaches that payload approximately $10$~dB earlier than position-domain indexing charged a realistic pilot budget.
