Across the world, there is growing interest in new waveforms, Zak-OTFS in particular, and over-the-air implementations are starting to appear. The choice between OFDM and Zak-OTFS is not so much a choice between waveforms as it is an architectural choice between preventing inter-carrier interference (ICI) and embracing ICI. In OFDM, once the Input-Output (I/O) relation is known, equalization is relatively simple, at least when there is no ICI. However, in the presence of ICI the I/O relation is non-predictable and its acquisition is non-trivial. In contrast, equalization is more involved in Zak-OTFS due to inter-symbol-interference (ISI), however the I/O relation is predictable and its acquisition is simple. {Zak-OTFS exhibits superior performance in doubly-spread 6G use cases with high delay/Doppler channel spreads (i.e., high mobility and/or large cells), but architectural choice is governed by the typical use case, today and in the future. What is typical depends to some degree on geography, since large delay spread is a characteristic of large cells which are the rule rather than the exception in many important wireless markets.} This paper provides a comprehensive performance comparison of cyclic prefix OFDM (CP-OFDM) and Zak-OTFS across the full range of 6G propagation environments. The performance results provide insights into the fundamental architectural choice.

翻译：全球范围内，对新波形（尤其是Zak-OTFS）的研究兴趣日益增长，空中接口实现方案也开始涌现。OFDM与Zak-OTFS之间的选择，与其说是波形选择，不如说是“抑制载波间干扰（ICI）”与“接纳ICI”两种架构理念的抉择。在OFDM中，一旦输入输出（I/O）关系已知，均衡过程相对简单（至少在无ICI条件下）。然而，当存在ICI时，其I/O关系具有不可预测性，且信道获取过程较为复杂。相比之下，Zak-OTFS因存在符号间干扰（ISI）使得均衡更为复杂，但其I/O关系具有可预测性，且信道获取过程简单。{Zak-OTFS在具有高时延/多普勒信道扩展（即高移动性和/或大覆盖范围）的双扩展6G应用场景中展现出优越性能，但架构选择需基于当前及未来的典型应用场景。典型场景特征在一定程度上受地域因素影响，因为大时延扩展是大覆盖网络的固有特性，而这在许多重要无线通信市场中已成为普遍现象而非特例。}本文针对6G全场景传播环境，对循环前缀OFDM（CP-OFDM）与Zak-OTFS进行了系统性性能比较。性能分析结果为这一基础性架构选择提供了重要参考依据。