发表机构
South China University of Technology; University of Missouri（华南理工大学; 密苏里大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出电磁孪生（ET）框架，通过递归同步状态实现持续CSI估计，利用UET-FISTA和ET-ADMM两种凸模式，在稀疏导频下显著提升信道估计精度和有效速率。
AI 中文摘要
每个重复的导频块通常被视为一个独立的信道估计问题，尽管大部分角度-时延状态在更新之间持续存在。本文定义电磁孪生（ET）为一种递归同步的信号处理状态，包含信道状态信息（CSI）、系数级不确定性、支持度置信度和年龄。信道知识图可初始化该状态；后续导频预测、校正、验证并存储该状态。我们构建了一个锚定窗口逆问题，其产生在线不确定性加权校正和固定滞后平滑，作为持久状态估计器的两种凸运行模式。不确定性感知的ET FISTA（UET-FISTA）提供零延迟更新，而交替方向乘子法（ET-ADMM）在允许延迟CSI时联合细化短窗口。留出导频在规定的族级错误接受概率下选择更新、完全刷新或保持，防止不准确的存储状态被盲目重用。条件贝叶斯Cramér-Rao界量化了存储状态和未来导频块提供的信息。使用20%导频时，UET-FISTA达到-11.55 dB的归一化均方误差，而静态FISTA为-3.42 dB。在200条独立50纪元轨迹上，三纪元平滑将匹配状态NMSE从-10.28 dB提升至-13.41 dB。在40条离网格QuaDRiGa轨迹上，在线UET-FISTA将静态恢复从-1.37 dB提升至-1.88 dB，有效速率从1.688提升至1.919 bit/s/Hz。这些结果识别了持续CSI何时减少导频需求，以及接收器何时应刷新或保持其状态。
英文摘要
Each repeated pilot block is typically treated as a separate channel-estimation problem, although much of the angle--delay state persists across updates. This paper defines an electromagnetic twin (ET) as a recursively synchronized signal-processing state containing channel state information (CSI), coefficientwise uncertainty, support confidence, and age. A channel knowledge map may initialize this state; subsequent pilots predict, correct, validate, and store the state. We formulate an anchored-window inverse problem that yields online uncertainty-weighted correction and fixed-lag smoothing as two convex operating modes of a persistent-state estimator. Uncertainty-aware ET FISTA (UET-FISTA) gives a zero-delay update, while an alternating direction method of multipliers (ET-ADMM) jointly refines a short window when delayed CSI is acceptable. Held-out pilots choose update, complete refresh, or hold under a prescribed family-wise false-acceptance probability, preventing an inaccurate stored state from being reused blindly. Conditional Bayesian Cramér--Rao bounds quantify the information supplied by the stored state and by future pilot blocks. With 20\% pilots, UET-FISTA reaches $-11.55$ dB normalized mean-square error, compared with $-3.42$ dB for static FISTA. Over 200 independent 50-epoch trajectories, three-epoch smoothing improves matched-state NMSE from $-10.28$ to $-13.41$ dB. On 40 off-grid QuaDRiGa trajectories, online UET-FISTA improves static recovery from $-1.37$ to $-1.88$ dB and effective rate from 1.688 to 1.919 bit/s/Hz. These results identify when persistent CSI reduces pilot demand and when the receiver should instead refresh or preserve its state.
