Terahertz Wireless Channels: A Holistic Survey on Measurement, Modeling, and Analysis

TL;DR

This paper provides a comprehensive survey of terahertz wireless channels, covering measurement techniques, modeling approaches, channel characteristics, and future research directions for 6G systems.

Contribution

It offers the first holistic overview of THz channel measurement, modeling, and analysis, highlighting current methodologies and open challenges for 6G wireless communications.

Findings

Comparison of measurement methodologies including VNA, sliding correlation, and THz-TDS.

Categorization of channel models into deterministic, stochastic, and hybrid approaches.

Identification of open problems and future research directions in THz wireless channels.

Abstract

Terahertz (0.1-10 THz) communications are envisioned as a key technology for sixth generation (6G) wireless systems. The study of underlying THz wireless propagation channels provides the foundations for the development of reliable THz communication systems and their applications. This article provides a comprehensive overview of the study of THz wireless channels. First, the three most popular THz channel measurement methodologies, namely, frequency-domain channel measurement based on a vector network analyzer (VNA), time-domain channel measurement based on sliding correlation, and time-domain channel measurement based on THz pulses from time-domain spectroscopy (THz-TDS), are introduced and compared. Current channel measurement systems and measurement campaigns are reviewed. Then, existing channel modeling methodologies are categorized into deterministic, stochastic, and hybrid approaches. State-of-the-art THz channel models are analyzed, and the channel simulators that are based on them are introduced. Next, an in-depth review of channel characteristics in the THz band is presented. Finally, open problems and future research directions for research studies on THz wireless channels for 6G are elaborated.