发表机构
Federal University of Ceará; Dalian University of Technology（塞阿拉联邦大学; 大连理工大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对三混合可重构天线系统，提出三线性信道估计框架TRACE，利用PARAFAC张量分解和交替最小二乘实现高精度信道恢复，性能接近oracle界。
AI 中文摘要
采用可重构天线（RA）的三混合波束赋形为射频（RF）模拟合并和基带处理增加了电磁（EM）域自由度，但同时也将EM角响应、空间转向矩阵和路径增益耦合到每个接收导频中。本文针对三混合接收机的单用户上行链路，提出了TRACE，一种三线性信道估计框架。通过沿导频维度循环辐射模式，接收导频构成三阶PARAFAC张量，其因子分别对应EM域角因子、RF投影转向因子和导频加权衰落因子。TRACE通过交替最小二乘拟合该张量，然后以闭式形式恢复物理信道参数。基于Kruskal的可辨识性转化为对导频时隙数、RF链和EM探测状态数的设计规则。在压缩配置下，TRACE达到oracle支撑界的SNR斜率，在10 dB以上保持在其1.4倍以内，同时优于基于字典的贪心基线。
英文摘要
Tri-hybrid beamforming with reconfigurable antennas (RAs) adds an electromagnetic (EM)-domain degree of freedom to radio-frequency (RF) analog combining and baseband processing, but it also couples the EM angular response, the spatial steering matrix, and the path gains inside every received pilot. This letter develops TRACE, a trilinear channel estimation framework for the single-user uplink of a tri-hybrid receiver. Cycling the radiation pattern over the pilot dimension yields a third-order PARAFAC tensor of the received pilots, with factors corresponding to the EM-domain angular factor, the RF-projected steering factor, and the pilot-weighted fading factor. TRACE fits this tensor by alternating least squares and then recovers the physical channel parameters in closed form. Kruskal-based identifiability translates into design rules for the number of pilot slots, RF chains, and EM probing states. In a compressive configuration, TRACE attains the SNR slope of an oracle-support bound, staying within a factor of $1.4$ of it above $10$~dB, while outperforming a dictionary-based greedy baseline.
