Integrated sensing and communication (ISAC) has the advantages of efficient spectrum utilization and low hardware cost. It is promising to be implemented in the fifth-generation-advanced (5G-A) and sixth-generation (6G) mobile communication systems, having the potential to be applied in intelligent applications requiring both communication and high-accurate sensing capabilities. As the fundamental technology of ISAC, ISAC signal directly impacts the performance of sensing and communication. This article systematically reviews the literature on ISAC signals from the perspective of mobile communication systems, including ISAC signal design, ISAC signal processing algorithms and ISAC signal optimization. We first review the ISAC signal design based on 5G, 5G-A and 6G mobile communication systems. Then, radar signal processing methods are reviewed for ISAC signals, mainly including the channel information matrix method, spectrum lines estimator method and super resolution method. In terms of signal optimization, we summarize peak-to-average power ratio (PAPR) optimization, interference management, and adaptive signal optimization for ISAC signals. This article may provide the guidelines for the research of ISAC signals in 5G-A and 6G mobile communication systems.

翻译：综合遥感和通信(ISAC)具有高效频谱利用和低硬件成本的优势,有望在第五代先进(5G-A)和第六代(6G)移动通信系统中实施,有可能应用于需要通信和高精确感测能力的智能应用。作为ISAC的基本技术,ISAC信号直接影响到遥感和通信的性能。本文章系统地从移动通信系统的角度审查ISAC信号的文献,包括ISAC信号设计、ISAC信号处理算法和ISAC信号优化。我们首先审查基于5G、5G-A和6G移动通信系统的ISAC信号设计。然后,对ISAC信号的雷达信号处理方法进行审查,主要包括频道信息矩阵方法、频谱线测算法和超分辨率方法。在信号优化方面,我们总结了ISAC信号的峰到平均功率比率(PAR)优化、干扰管理和适应性信号优化。本文章可为5G-A和6G移动通信系统的ISAC信号研究提供指导方针。