Timing Misalignment and Its Impact on OTFS and Other Delay-Based Waveforms
Istanbul Medipol University（伊斯坦布尔梅迪波尔大学）；KAUST（阿卜杜拉国王科技大学）
Badr Eddine Ouakouak, Salah Eddine Zegrar, Hüseyin Arslan
备注：
Published in: IEEE Transactions on Communications. Date of Publication: 01 September 2026. Volume: 74. Page(s): 13657 - 13671. no ISSUE number is shown yet
发表信息：
IEEE Transactions on Communications 73 (2026): 12008-12022
The shift towards 6G wireless networks calls for advanced waveforms to support emerging applications such as ultra-reliable and massive machine-type communications. Among the proposed candidates, OTFS, ODDM, OTSM, and OCDM share the common feature of exploiting the delay domain for data transmission. While these waveforms offer significant advantages in high-mobility and sensing scenarios, their integration into multi-user uplink systems reveals a critical challenge: timing misalignment (TM). Unlike OFDM, where residual timing offsets translate into phase rotations, delay-based waveforms experience actual shifts of resources, whose impact we investigate in this work. We show that the aforementioned waveforms can be unified under a time-invariant setup through a common input--output relation, which enables a unified analysis of TM in uplink resource allocation. The results reveal a fundamental trade-off between interference mitigation and guard overhead in the presence of TM. We further benchmark the observed behavior against OFDM under Doppler spread as a reference impairment and highlight the analogy between TM in delay-based allocation and Doppler spread in frequency-based allocation. The results show that delay-based waveforms can maintain a net performance advantage over OFDM in the considered setup. Beyond this unified Doppler-free analysis, we evaluate the joint impact of Doppler spread and TM on each waveform individually. We also investigate BER performance and show how coding can mitigate the resulting interference. This study therefore establishes a problem framework that motivates the development of future compensation and scheduling strategies for practical multi-user operation of delay-based waveforms.
Does 6G Need a New Waveform: Comparing Zak-OTFS with CP-OFDM
Indian Institute of Technology Delhi（印度理工学院德里分校）；University of Texas at Austin（德克萨斯大学奥斯汀分校）；Cohere Technologies Inc.（Cohere科技有限公司）；Indian Institute of Science Bangalore（班加罗尔印度科学研究所）；Duke University（杜克大学）
On the Spectrum of OTFS/VOFDM Signals: PSD Analysis and Bandwidth Allocation
School of Information Science and Technology, Harbin Institute of Technology (Shenzhen)（哈尔滨工业大学（深圳）信息科学与工程学院）；Department of Electrical and Computer Engineering, University of Delaware（特拉华大学电气与计算机工程系）
Low-complexity Equalization of Zak-OTFS Via Neumann Series
Duke University（杜克大学）；Department of Electrical Engineering, Indian Institute of Technology Delhi（德里印度理工学院电气工程系）；Cohere Technologies Inc.（Cohere科技有限公司）；Department of Mathematics, University of Texas at Austin（德克萨斯大学奥斯汀分校数学系）
Prior-Aided Iterative Channel Reconstruction with Optimized Frame Structure for DSE Mitigation in CP-OTFS-Based LEO Satellite Systems
Beijing University of Posts and Telecommunications（北京邮电大学）；University of Science and Technology Beijing（北京科技大学）；Tsinghua University（清华大学）；China Mobile Research Institute（中国移动研究院）
Delay-Doppler Domain Signal Processing Aided OFDM (DD-a-OFDM) for 6G and Beyond
Beijing Jiaotong University（北京交通大学）；University of New South Wales（新南威尔士大学）；Technical University of Berlin（柏林工业大学）；Queensland University of Technology（昆士兰科技大学）；Southern University of Science and Technology（南方科技大学）；Xi’an Jiaotong University（西安交通大学）；Southeast University（东南大学）
Cyclic Delay-Doppler Shift: A Simple Transmit Diversity Technique for Ultra-Reliable Communications in Doubly Selective Channels
Sun Yat-sen University（中山大学）；Guangdong Provincial Key Laboratory of Sea-Air-Space Communication（广东省海空天通信重点实验室）；National Mobile Communications Research Laboratory（移动通信国家重点实验室）
