AI 中文总结
针对太赫兹频段室内场景跨场信道参数估计与表征难题，建立测量框架获取数据，提出跨场空间交替广义期望最大化算法，有效解决跨场多径分量问题，为太赫兹通信系统信道建模和设计提供定量指导。
AI 中文摘要
太赫兹（THz）频段为未来无线通信系统中超高数据速率传输提供了潜力。为扩展传输距离并提高频谱效率，大规模天线阵列的部署成为太赫兹频段有前景的解决方案。本文针对此类配置中跨场（混合近场/远场）信道参数估计和信道表征这一关键挑战。首先在室内场景建立260 - 380 GHz虚拟均匀线性阵列（ULA）测量框架，获取揭示空间非平稳性和跨场波前特性的高分辨率信道传递函数（CTF）。在此基础上，提出跨场空间交替广义期望最大化（SAGE）算法，通过贝叶斯相位曲率分类判别估计近场和远场多径分量（MPC），并通过可见区域估计明确跟踪空间生灭现象。测量数据分析验证了该算法在解决跨场MPC方面的有效性，并量化了在2米传输距离（380 GHz）近场MPC占总MPC的90%以上。还观察到随着载波频率增加和传输距离减小，空间非平稳性加剧。这些发现为无线太赫兹通信系统中的信道建模和系统设计提供了定量指导。
英文摘要
The terahertz (THz) frequency band offers the potential for ultra-high data rate transmission in future wireless communication systems. To extend the transmission distance and enhance spectral efficiency, the deployment of large-scale antenna arrays emerges as a promising solution in the THz band. This paper targets the critical challenge of cross-field (hybrid near-field/far-field) channel parameter estimation and channel characterization in such configurations. We first establish a 260-380 GHz virtual uniform linear array (ULA) measurement framework in an indoor scenario, capturing high-resolution channel transfer functions (CTFs) that reveal spatial non-stationarity and cross-field wavefront characteristics. Building upon these empirical observations, we propose a cross-field space-alternating generalized expectation-maximization (SAGE) algorithm that discriminatively estimates near-field and far-field multipath components (MPCs) via Bayesian phase-curvature classification, while explicitly tracking spatial birth-death phenomena through visibility region estimation. Analysis of the measurement data validates the algorithm's effectiveness in resolving cross-field MPCs and quantifies that near-field MPCs account for over 90% of total MPCs at 2 m transmission distance (380 GHz). We observe that spatial non-stationarity intensifies as the carrier frequency increases and the transmission distance decreases. These findings offer quantitative guidelines for channel modeling and system design in wireless THz communication systems.
Comments13 pages, 19 figures
