TeraHertz Band Communication: An Old Problem Revisited and Research Directions for the Next Decade

Abstract

TeraHertz (THz) band communications are envisioned as a key technology for 6G and Beyond. As a fundamental wireless infrastructure, THz communication can boost abundant promising applications. In 2014, our team published two comprehensive roadmaps for the development and progress of THz communication networks [1], [2], which helped the research community to start research on this subject afterwards. In particular, this topic became very important and appealing to the research community due to 6G wireless systems design and development in recent years. Many papers are getting published covering different aspects of wireless systems using the THz band. With this paper, our aim is looking back to the last decade and revisiting the old problems and pointing out what has been achieved in the research community so far. Furthermore, in this paper still to be investigated new research challenges for the THz band communication systems are presented by covering diverse subtopics such as from perspectives of devices, channel behavior, communication and networking problems, physical testbeds and demonstration systems. The key aspects presented in this paper will enable THz communications as a pillar of 6G and Beyond wireless systems in the next decade.

Performance Analysis of Time-Hopping Multiple Access Using Multi-Level PPM for Terahertz Nanocommunication

“…The EM nanonetworks are typically envisioned to operate in the THz band, i.e., from 0.1 THz to 10 THz [1], [4], [15], [18]- [20]. The terahertz channel developed in [14] captures the behavior of entire THz band including the molecular absorption loss.…”

“…2 dt and σ 2 n is the variance of the nanoreceiver noise. Now, provided that the noise level must be kept lower than the signal level to guarantee a certain BER and demodulate the signal as per ML decision rule (18), the joint p.d.f. f y k,j (x 1 , x 2 , ...x L ; j) can be defined to be likelihood function as…”

“…The communication distances could be increased up to a few meters, by identifying several transparency windows in the THz band, however, at the cost of achievable data rate [16], [17]. Nevertheless, 0.1 THz to 10 THz band is chosen to be the preferred frequency band of operation for the nanomachines [1], [18]- [20] due to several reasons, one being the graphene nanoantennas [21], [22] and plasmonic field-effect transistors (TeraFETs) [23] being established to operate in the THz band, which will result in the nanotranceivers design using graphene and its derivatives [24]- [26].…”

On Multiple-Antenna Techniques for Physical-Layer Range Security in the Terahertz Band

“…With an increasing demand for high-speed, reliable, and private information exchange, a new spectrum, as well as advanced security technologies, are awaited to be developed for next-generation wireless networks. The Terahertz (THz) band, with frequencies ranging from 0.1 to 10 THz, is envisioned to realize multi-Gbps or even Tbps data rates owing to the abundant bandwidth resource [1]- [3]. In addition to the bandwidth merit, the potential of THz communications to improve the information security is envisioned in [4], [5].…”

Sionna: An Open-Source Library for Next-Generation Physical Layer Research

“…Some of the most prominent 6G research topics are communication in the Terahertz band [4], cell-free, holographic, and very large aperture multiple-input multiple-output (MIMO) [5], unmanned aerial vehicle (UAV) and satellite communication [6], machine learning (ML)-based air interface design [7], semantic communication [8], reconfigurable intelligent surfaces (RIS) [9], sensing and localization [10], digital twins [11], computer vision for wireless [12], as well as federated learning over wireless [13]. Interestingly, research on most of the above topics requires one or more of the following:…”