HF communications: Past, present, and future

• Published in: China communications Vol. 15; no. 9; pp. 1 - 9
• Main Authors: Wang, Jinlong, Ding, Guoru, Wang, Haichao
• Format: Journal Article
• Language: English
• Published: China Institute of Communications 01.09.2018; College of Communications Engineering, Army Engineering University of PLA, Nanjing 210007, China%College of Communications Engineering, Army Engineering University of PLA, Nanjing 210007, China; National Mobile Communications Research Laboratory, Southeast University, Nanjing 210096, China
• Subjects: Aircraft; artificial intelligence; cognitive radio; HF communications; ionospheric refraction; Marine vehicles; Receivers; skywave propagation; Tutorials; Wideband; skywave propagation; HF communications; cognitive radio; ionospheric refraction; artificial intelligence
• ISSN: 1673-5447
• DOI: 10.1109/CC.2018.8456447

High frequency (HF) communication, commonly covering frequency range between 3 and 30 MHz, is an important wireless communication paradigm to offer over-the-horizon or even global communications with ranges up to thousands of kilometers via sky-wave propagation with ionospheric refraction. It has widespread applications in fields such as emergency communications in disaster areas, remote communications with aircrafts or ships and non-light-of-the-sight military operations. This tutorial article overviews the history of HF communication, demystifies the recent advances, and provides a preview of the next few years, which the authors believe will see fruitful outputs towards wideband, intelligent and integrated HF communications. Specifically, we first present brief preliminaries on the unique features of HF communications to facilitate general readers in the communication community. Then, we provide a historical review to show the technical evolution on the three generations of HF communication systems. Further, we highlight the key challenges and research directions. We hope that this article will stimulate more interests in addressing the technical challenges on the research and development of future HF radio communication systems.