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

TL;DR

This paper introduces OTFS, a 2D modulation scheme designed for 6G networks to improve communication reliability in high-mobility, high-frequency scenarios by encoding information in the delay-Doppler domain.

Contribution

It provides an overview of OTFS, discusses its challenges, preliminary results, and explores future research opportunities and applications in 6G wireless systems.

Findings

OTFS effectively handles channel dynamics in high-mobility scenarios.

Preliminary results show OTFS's robustness against Doppler effects.

OTFS offers promising applications for 6G wireless networks.

Abstract

The sixth-generation (6G) wireless networks are envisioned to provide a global coverage for the intelligent digital society of the near future, ranging from traditional terrestrial to non-terrestrial 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-dimensional 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.