This article presents details about an extensive channel measurement campaign and subsequent statistical channel models for the characterization of 300 GHz channels for wireless rack-to-rack (R2R) and blade-to-blade (B2B) communications in a data center-like environment. Measurements were conducted in various scenarios such as R2R line-of-sight (LoS), R2R obstructed-LoS (OLoS), R2R reflected-non-LoS (RNLoS), R2R obstructed-RNLoS (ORNLoS), B2B RNLoS, B2B ORNLoS, and B2B LoS scenarios. In the aforementioned scenarios, we explored the impact of transmitter (Tx)/receiver (Rx) misalignment and obstructions such as cables, metal cabinets, and mesh structures on terahertz (THz) propagation, as well as feasibility of using existing metal objects as reflectors for NLoS links. For the R2R LoS scenario, an optical lens was used to extend the Tx-Rx separation distance. This led to a waveguide effect in the channels measured thereby resulting into a path loss exponent (PLE) of 1.48 with a shadowing gain of 0.7 dB. When obstructions of cables are present, ORNLoS link outperforms OLoS link with 2.5 dB lower shadowing gain and weaker multipath. Reflector in the RNLoS link has reflection coefficients very close to 1 for all incident angles. For the B2B scenario, a dual-reflector THz transceiver rack system is proposed to enable wireless links across vertically stacked servers and allow easy maintenance and repair of servers. The measured path loss closely follows the Friis values in the LoS link and in the RNLoS link with hollow vertical ground plane. When obstructions of cables are present, the ORNLoS link experiences 5–10 dB higher path loss and on average 0.25 GHz lower coherence bandwidth than the RNLoS link. The measured statistical channel properties show that the shadowing gain caused by cable clusters follows the log-normal distribution.

中文翻译：

---

与 300 GHz 无线数据中心链路相关的传播现象的表征

本文详细介绍了广泛的信道测量活动和随后的统计信道模型，用于表征数据中心环境中无线机架到机架 (R2R) 和刀片到刀片 (B2B) 通信的 300 GHz 信道。在各种场景下进行测量，例如 R2R 视线 (LoS)、R2R 受阻视距 (OLoS)、R2R 反射非视距 (RNLoS)、R2R 受阻 RNLoS (ORNLoS)、B2B RNLoS、B2B ORNLoS、和 B2B 视距场景。在上述场景中，我们探讨了发射器 (Tx)/接收器 (Rx) 未对准和电缆、金属机柜和网状结构等障碍物对太赫兹 (THz) 传播的影响，以及使用现有金属物体作为反射器的可行性用于 NLoS 链接。对于 R2R LoS 场景，一个光学镜头被用来延长 Tx-Rx 的分离距离。这导致测量的通道中出现波导效应，从而导致路径损耗指数 (PLE) 为 1.48，遮蔽增益为 0.7 dB。当存在电缆障碍物时，ORNLoS 链路性能优于 OLoS 链路，具有 2.5 dB 较低的阴影增益和较弱的多径。对于所有入射角，RNLoS 链路中的反射器的反射系数都非常接近 1。对于 B2B 场景，提出了双反射器太赫兹收发器机架系统，以实现垂直堆叠服务器之间的无线链接，并允许轻松维护和维修服务器。测得的路径损耗与 LoS 链路和具有空心垂直接地平面的 RNLoS 链路中的 Friis 值密切相关。当存在电缆障碍物时，ORNLoS 链路的路径损耗比 RNLoS 链路高 5-10 dB，相干带宽平均低 0.25 GHz。测量的统计信道特性表明，由电缆簇引起的阴影增益遵循对数正态分布。