Orthogonal Time Frequency Space Modulation -- Part I: Fundamentals and Challenges Ahead

TL;DR

This paper introduces the fundamentals of OTFS modulation, compares two implementation architectures, and discusses its potential benefits and future challenges for wireless networks.

Contribution

It provides a comprehensive overview of OTFS modulation, including two implementation methods and an analysis of its core concepts and challenges.

Findings

Comparison of SFFT- and DZT-based OTFS architectures

Discussion of OTFS benefits in delay-Doppler domain

Identification of future challenges for OTFS

Abstract

This letter is the first part of a three-part tutorial on orthogonal time frequency space (OTFS) modulation, which is a promising candidate waveform for future wireless networks. This letter introduces and compares two popular implementations of OTFS modulation, namely the symplectic finite Fourier transform (SFFT)- and discrete Zak transform (DZT)-based architectures. Based on these transceiver architectures, fundamental concepts of OTFS modulation, including the delay-Doppler (DD) domain, DD domain information multiplexing, and its potential benefits, are discussed. Finally, the challenges ahead for OTFS modulation are highlighted. Parts II and III of this tutorial on OTFS modulation focus on transceiver designs and integrated sensing and communication (ISAC), respectively.