Integrated sensing and communication (ISAC) is viewed as a crucial component of future mobile networks and has gained much interest in both academia and industry. Similar to the emergence of radio-frequency (RF) ISAC, the integration of free space optical communication and optical sensing yields optical ISAC (O-ISAC), which is regarded as a powerful complement to its RF counterpart. In this article, we first introduce the generalized system structure of O-ISAC, and then elaborate on three advantages of O-ISAC, i.e., increasing communication rate, enhancing sensing precision, and reducing interference. Next, waveform design and resource allocation of O-ISAC are discussed based on pulsed waveform, constant-modulus waveform, and multi-carrier waveform. Furthermore, we put forward future trends and challenges of O-ISAC, which are expected to provide some valuable directions for future research.

翻译：集成感知与通信（ISAC）被视为未来移动网络的关键组成部分，并已在学术界和工业界引起广泛关注。类似于射频（RF）ISAC的出现，自由空间光通信与光学感知的融合衍生出光学ISAC（O-ISAC），该技术被视作射频ISAC的有力补充。本文首先介绍O-ISAC的广义系统结构，进而详述其三大优势，即提升通信速率、增强感知精度与降低干扰。随后，基于脉冲波形、恒模波形及多载波波形，探讨了O-ISAC的波形设计与资源分配问题。最后，提出O-ISAC的未来趋势与挑战，以期为后续研究提供有价值的指导方向。