Sub-THz Communications: Perspective and Results from the Hexa-X-II Project
Journal article, 2025
Sub-THz communications are envisioned to unlock ultra-high data rates, ultra-low latencies, and massive connectivity in future wireless systems by utilizing bandwidths of up to tens of GHz. This paper presents the holistic perspective on sub-THz communications developed within the European sixthgeneration (6G) flagship project Hexa-X-II. According to this perspective, successfully deploying sub-THz systems will require addressing several physical-layer (PHY) challenges associated with the harsh signal propagation and hardware limitations. In addition, sub-THz systems will drive advancements in essential wireless applications beyond communications, such as joint communications and sensing (JCAS). In this context, we present a collection of technical contributions and key findings from the Hexa-X-II project that have shaped this perspective. In contrast to existing works, these efforts collectively tackle the fundamental PHY challenges of sub-THz communications, i.e., understanding and modeling of radio propagation, radio-frequency (RF) power consumption and complexity, and hardware impairments. To achieve this, we present several results across three core areas, i.e., signal propagation and channel modeling, RF transceiver design, and PHY enablers, offering useful insights into the development of sub-THz systems. Lastly, we provide an overview of sub-THz JCAS, emphasizing it as one of the most promising applications in the sub-THz range.
sub-THz RF transceiver design
6G
Sub-THz communications
sub-THz PHY enablers
sub-THz JCAS
sub-THz channel modeling
Author
Italo Atzeni
University of Oulu
Gustavo Rodrigues de Lima Tejerina
University of Oulu
Rafael Berkvens
IMEC
Hui Chen
Chalmers, Electrical Engineering, Communication, Antennas and Optical Networks
Jean Marc Conrat
Aalto University
Mar Francis De Guzman
Technische Universität Dresden
Claude Desset
IMEC
Meik Dörpinghaus
Ericsson
Hamed Farhadi
Nokia
G. Fettweis
Ericsson
Florian Gast
Ericsson
Hardy Halbauer
Nokia
Rreze Halili
IMEC
Katsuyuki Haneda
Technische Universität Dresden
Ilkka Harjula
Orange Innovation
Bruno Jahan
Apple
Ramin Khayatzadeh
Nokia
Pekka Kyosti
University of Oulu
Rodolphe Legouable
Apple
Arto Lehti
Nokia
Dileepa Marasinghe
University of Oulu
Le Hang Nguyen
Nokia
Sharief Saleh
Chalmers, Electrical Engineering, Communication, Antennas and Optical Networks
Kaan Senparlak
Nokia
Nuutti Tervo
University of Oulu
Oskari Tervo
Orange Innovation
Henk Wymeersch
Chalmers, Electrical Engineering, Communication, Antennas and Optical Networks
Bo Xu
Nokia
Peize Zhang
University of Oulu
IEEE Open Journal of the Communications Society
2644125X (eISSN)
Vol. In PressSubject Categories (SSIF 2025)
Communication Systems
Telecommunications
Signal Processing
DOI
10.1109/OJCOMS.2025.3591836