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：通信感知一体化（ISAC）具有频谱利用率高和硬件成本低的优势，有望在第五代增强版（5G-A）和第六代（6G）移动通信系统中实现，并具备应用于需要同时具备通信与高精度感知能力的智能应用的潜力。作为ISAC的基础技术，ISAC信号直接决定感知与通信的性能。本文从移动通信系统的角度系统综述了ISAC信号的文献，涵盖ISAC信号设计、ISAC信号处理算法及ISAC信号优化。我们首先回顾了基于5G、5G-A和6G移动通信系统的ISAC信号设计。随后，针对ISAC信号综述了雷达信号处理方法，主要包括信道信息矩阵法、频谱线估计法和超分辨率法。在信号优化方面，我们总结了ISAC信号的峰均功率比（PAPR）优化、干扰管理及自适应信号优化。本文可为5G-A与6G移动通信系统中ISAC信号的研究提供指导。