基于ODDM调制的6G通感一体化系统波形设计：基础、挑战和未来方向

摘要：6G无线网络将提供全球覆盖的通信服务，覆盖范围将从地面通信网络到空天地一体化网网络，在该高速移动场景下，传统的正交频分复用（OFDM）由于存在多普勒偏移会导致性能下降。为了克服这一障碍，一种基于时延多普勒（DD）域正交脉冲的正交时延多普勒分集复用（ODDM）调制被提出，实现了DD域精细时间和频率分辨率上的正交性。通信感知一体化（ISAC）技术被视为下一代无线通信的一项有前景的技术，由于ODDM能够实现DD域上的信号与信道完美耦合，使其能够在通感一体化系统实现高可靠通信和高精度感知。详细介绍了ODDM调制技术在未来通感一体化网络的波形设计应用前景，以及ODDM基础理论与特点，并对当前DD域调制方法进行了调研和比较。最后提出ODDM面临的关键挑战以及未来在通感一体化波形设计方面的潜在方向。本研究可为面向未来大规模天线阵列高速移动场景下的通感一体化波形设计提供思路。

关键词：通感一体化；正交时延多普勒分集复用；波形设计

Abstract: The 6G wireless network will provide global coverage communication services, ranging from ground communication networks to space-air-ground networks. In these high-mobility scenarios, traditional orthogonal frequency division multiplexing (OFDM) suffers performance degradation due to Doppler shifts. To overcome this obstacle, orthogonal delay-Doppler modulation (ODDM) modulation based on delay-Doppler (DD) domain orthogonal pulses has been proposed, achieving orthogonality in the DD domain with fine time and frequency resolution. Integrated sensing and communications (ISAC) technology is regarded as a promising approach for next-generation wireless communication, and ODDM modulation, with its ability to achieve perfect coupling between signal and channels in the DD domain, enables high-reliability communication and high-precision in ISAC systems. The prospects of ODDM modulation technology in the future ISAC networks’ waveform design are elaborated. The fundamental theory and characteristics of ODDM are introducesd, and the research and comparison of current DD domain modulation methods are presented. Finally, the key challenges faced by ODDM and potential directions for future waveform design in ISAC systems are prospected. This study can be a reference for the future waveform design in ISAC systems for large-scale antenna arrays in high-speed mobile scenarios in the future.

Keywords: integrated sensing and communication; orthogonal delay-Doppler division multiplexing; waveform design