Orthogonal Time-Frequency Space Modulation: A Promising Next-Generation Waveform

• Published in: IEEE wireless communications Vol. 28; no. 4; pp. 136 - 144
• Main Authors: Wei, Zhiqiang, Yuan, Weijie, Li, Shuangyang, Yuan, Jinhong, Bharatula, Ganesh, Hadani, Ronny, Hanzo, Lajos
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: 6G mobile communication; Carrier frequencies; Cellular communication; Delays; Doppler effect; Fading channels; Frequency division multiplexing; Frequency modulation; Modulation; OFDM; Orthogonal Frequency Division Multiplexing; Time-frequency analysis; Waveforms; Wireless networks
• ISSN: 1536-1284; 1558-0687
• DOI: 10.1109/MWC.001.2000408

Sixth-generation (6G) wireless networks are envisioned to provide global coverage for the intelligent digital society of the near future, ranging from traditional terrestrial to non-terrestri-al networks, where reliable communications in high-mobility scenarios at high carrier frequencies would play a vital role. In such scenarios, the conventional orthogonal frequency division multiplexing (OFDM) modulation, that has been widely used in both the fourth-generation (4G) and the emerging fifth-generation (5G) cellular systems as well as in WiFi networks, is vulnerable to severe Doppler spread. In this context, this article aims to introduce a recently proposed two-dimension-al modulation scheme referred to as orthogonal time-frequency space (OTFS) modulation, which conveniently accommodates the channel dynamics via modulating information in the delay-Doppler domain. This article provides an easy-reading overview of OTFS, highlighting its underlying motivation and specific features. The critical challenges of OTFS and our preliminary results are presented. We also discuss a range of promising research opportunities and potential applications of OTFS in 6G wireless networks.